1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Security-Enhanced Linux (SELinux) security module
4  *
5  *  This file contains the SELinux hook function implementations.
6  *
7  *  Authors:  Stephen Smalley, <stephen.smalley.work@gmail.com>
8  *	      Chris Vance, <cvance@nai.com>
9  *	      Wayne Salamon, <wsalamon@nai.com>
10  *	      James Morris <jmorris@redhat.com>
11  *
12  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
13  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
14  *					   Eric Paris <eparis@redhat.com>
15  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
16  *			    <dgoeddel@trustedcs.com>
17  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
18  *	Paul Moore <paul@paul-moore.com>
19  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
20  *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
21  *  Copyright (C) 2016 Mellanox Technologies
22  */
23 
24 #include <linux/init.h>
25 #include <linux/kd.h>
26 #include <linux/kernel.h>
27 #include <linux/kernel_read_file.h>
28 #include <linux/errno.h>
29 #include <linux/sched/signal.h>
30 #include <linux/sched/task.h>
31 #include <linux/lsm_hooks.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/proc_fs.h>
40 #include <linux/swap.h>
41 #include <linux/spinlock.h>
42 #include <linux/syscalls.h>
43 #include <linux/dcache.h>
44 #include <linux/file.h>
45 #include <linux/fdtable.h>
46 #include <linux/namei.h>
47 #include <linux/mount.h>
48 #include <linux/fs_context.h>
49 #include <linux/fs_parser.h>
50 #include <linux/netfilter_ipv4.h>
51 #include <linux/netfilter_ipv6.h>
52 #include <linux/tty.h>
53 #include <net/icmp.h>
54 #include <net/ip.h>		/* for local_port_range[] */
55 #include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
56 #include <net/inet_connection_sock.h>
57 #include <net/net_namespace.h>
58 #include <net/netlabel.h>
59 #include <linux/uaccess.h>
60 #include <asm/ioctls.h>
61 #include <linux/atomic.h>
62 #include <linux/bitops.h>
63 #include <linux/interrupt.h>
64 #include <linux/netdevice.h>	/* for network interface checks */
65 #include <net/netlink.h>
66 #include <linux/tcp.h>
67 #include <linux/udp.h>
68 #include <linux/dccp.h>
69 #include <linux/sctp.h>
70 #include <net/sctp/structs.h>
71 #include <linux/quota.h>
72 #include <linux/un.h>		/* for Unix socket types */
73 #include <net/af_unix.h>	/* for Unix socket types */
74 #include <linux/parser.h>
75 #include <linux/nfs_mount.h>
76 #include <net/ipv6.h>
77 #include <linux/hugetlb.h>
78 #include <linux/personality.h>
79 #include <linux/audit.h>
80 #include <linux/string.h>
81 #include <linux/mutex.h>
82 #include <linux/posix-timers.h>
83 #include <linux/syslog.h>
84 #include <linux/user_namespace.h>
85 #include <linux/export.h>
86 #include <linux/msg.h>
87 #include <linux/shm.h>
88 #include <linux/bpf.h>
89 #include <linux/kernfs.h>
90 #include <linux/stringhash.h>	/* for hashlen_string() */
91 #include <uapi/linux/mount.h>
92 #include <linux/fsnotify.h>
93 #include <linux/fanotify.h>
94 #include <linux/io_uring.h>
95 
96 #include "avc.h"
97 #include "objsec.h"
98 #include "netif.h"
99 #include "netnode.h"
100 #include "netport.h"
101 #include "ibpkey.h"
102 #include "xfrm.h"
103 #include "netlabel.h"
104 #include "audit.h"
105 #include "avc_ss.h"
106 
107 #define SELINUX_INODE_INIT_XATTRS 1
108 
109 struct selinux_state selinux_state;
110 
111 /* SECMARK reference count */
112 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
113 
114 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
115 static int selinux_enforcing_boot __initdata;
116 
enforcing_setup(char * str)117 static int __init enforcing_setup(char *str)
118 {
119 	unsigned long enforcing;
120 	if (!kstrtoul(str, 0, &enforcing))
121 		selinux_enforcing_boot = enforcing ? 1 : 0;
122 	return 1;
123 }
124 __setup("enforcing=", enforcing_setup);
125 #else
126 #define selinux_enforcing_boot 1
127 #endif
128 
129 int selinux_enabled_boot __initdata = 1;
130 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
selinux_enabled_setup(char * str)131 static int __init selinux_enabled_setup(char *str)
132 {
133 	unsigned long enabled;
134 	if (!kstrtoul(str, 0, &enabled))
135 		selinux_enabled_boot = enabled ? 1 : 0;
136 	return 1;
137 }
138 __setup("selinux=", selinux_enabled_setup);
139 #endif
140 
checkreqprot_setup(char * str)141 static int __init checkreqprot_setup(char *str)
142 {
143 	unsigned long checkreqprot;
144 
145 	if (!kstrtoul(str, 0, &checkreqprot)) {
146 		if (checkreqprot)
147 			pr_err("SELinux: checkreqprot set to 1 via kernel parameter.  This is no longer supported.\n");
148 	}
149 	return 1;
150 }
151 __setup("checkreqprot=", checkreqprot_setup);
152 
153 /**
154  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
155  *
156  * Description:
157  * This function checks the SECMARK reference counter to see if any SECMARK
158  * targets are currently configured, if the reference counter is greater than
159  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
160  * enabled, false (0) if SECMARK is disabled.  If the always_check_network
161  * policy capability is enabled, SECMARK is always considered enabled.
162  *
163  */
selinux_secmark_enabled(void)164 static int selinux_secmark_enabled(void)
165 {
166 	return (selinux_policycap_alwaysnetwork() ||
167 		atomic_read(&selinux_secmark_refcount));
168 }
169 
170 /**
171  * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
172  *
173  * Description:
174  * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
175  * (1) if any are enabled or false (0) if neither are enabled.  If the
176  * always_check_network policy capability is enabled, peer labeling
177  * is always considered enabled.
178  *
179  */
selinux_peerlbl_enabled(void)180 static int selinux_peerlbl_enabled(void)
181 {
182 	return (selinux_policycap_alwaysnetwork() ||
183 		netlbl_enabled() || selinux_xfrm_enabled());
184 }
185 
selinux_netcache_avc_callback(u32 event)186 static int selinux_netcache_avc_callback(u32 event)
187 {
188 	if (event == AVC_CALLBACK_RESET) {
189 		sel_netif_flush();
190 		sel_netnode_flush();
191 		sel_netport_flush();
192 		synchronize_net();
193 	}
194 	return 0;
195 }
196 
selinux_lsm_notifier_avc_callback(u32 event)197 static int selinux_lsm_notifier_avc_callback(u32 event)
198 {
199 	if (event == AVC_CALLBACK_RESET) {
200 		sel_ib_pkey_flush();
201 		call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
202 	}
203 
204 	return 0;
205 }
206 
207 /*
208  * initialise the security for the init task
209  */
cred_init_security(void)210 static void cred_init_security(void)
211 {
212 	struct task_security_struct *tsec;
213 
214 	tsec = selinux_cred(unrcu_pointer(current->real_cred));
215 	tsec->osid = tsec->sid = SECINITSID_KERNEL;
216 }
217 
218 /*
219  * get the security ID of a set of credentials
220  */
cred_sid(const struct cred * cred)221 static inline u32 cred_sid(const struct cred *cred)
222 {
223 	const struct task_security_struct *tsec;
224 
225 	tsec = selinux_cred(cred);
226 	return tsec->sid;
227 }
228 
__ad_net_init(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,struct sock * sk,u16 family)229 static void __ad_net_init(struct common_audit_data *ad,
230 			  struct lsm_network_audit *net,
231 			  int ifindex, struct sock *sk, u16 family)
232 {
233 	ad->type = LSM_AUDIT_DATA_NET;
234 	ad->u.net = net;
235 	net->netif = ifindex;
236 	net->sk = sk;
237 	net->family = family;
238 }
239 
ad_net_init_from_sk(struct common_audit_data * ad,struct lsm_network_audit * net,struct sock * sk)240 static void ad_net_init_from_sk(struct common_audit_data *ad,
241 				struct lsm_network_audit *net,
242 				struct sock *sk)
243 {
244 	__ad_net_init(ad, net, 0, sk, 0);
245 }
246 
ad_net_init_from_iif(struct common_audit_data * ad,struct lsm_network_audit * net,int ifindex,u16 family)247 static void ad_net_init_from_iif(struct common_audit_data *ad,
248 				 struct lsm_network_audit *net,
249 				 int ifindex, u16 family)
250 {
251 	__ad_net_init(ad, net, ifindex, NULL, family);
252 }
253 
254 /*
255  * get the objective security ID of a task
256  */
task_sid_obj(const struct task_struct * task)257 static inline u32 task_sid_obj(const struct task_struct *task)
258 {
259 	u32 sid;
260 
261 	rcu_read_lock();
262 	sid = cred_sid(__task_cred(task));
263 	rcu_read_unlock();
264 	return sid;
265 }
266 
267 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
268 
269 /*
270  * Try reloading inode security labels that have been marked as invalid.  The
271  * @may_sleep parameter indicates when sleeping and thus reloading labels is
272  * allowed; when set to false, returns -ECHILD when the label is
273  * invalid.  The @dentry parameter should be set to a dentry of the inode.
274  */
__inode_security_revalidate(struct inode * inode,struct dentry * dentry,bool may_sleep)275 static int __inode_security_revalidate(struct inode *inode,
276 				       struct dentry *dentry,
277 				       bool may_sleep)
278 {
279 	struct inode_security_struct *isec = selinux_inode(inode);
280 
281 	might_sleep_if(may_sleep);
282 
283 	if (selinux_initialized() &&
284 	    isec->initialized != LABEL_INITIALIZED) {
285 		if (!may_sleep)
286 			return -ECHILD;
287 
288 		/*
289 		 * Try reloading the inode security label.  This will fail if
290 		 * @opt_dentry is NULL and no dentry for this inode can be
291 		 * found; in that case, continue using the old label.
292 		 */
293 		inode_doinit_with_dentry(inode, dentry);
294 	}
295 	return 0;
296 }
297 
inode_security_novalidate(struct inode * inode)298 static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
299 {
300 	return selinux_inode(inode);
301 }
302 
inode_security_rcu(struct inode * inode,bool rcu)303 static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
304 {
305 	int error;
306 
307 	error = __inode_security_revalidate(inode, NULL, !rcu);
308 	if (error)
309 		return ERR_PTR(error);
310 	return selinux_inode(inode);
311 }
312 
313 /*
314  * Get the security label of an inode.
315  */
inode_security(struct inode * inode)316 static struct inode_security_struct *inode_security(struct inode *inode)
317 {
318 	__inode_security_revalidate(inode, NULL, true);
319 	return selinux_inode(inode);
320 }
321 
backing_inode_security_novalidate(struct dentry * dentry)322 static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
323 {
324 	struct inode *inode = d_backing_inode(dentry);
325 
326 	return selinux_inode(inode);
327 }
328 
329 /*
330  * Get the security label of a dentry's backing inode.
331  */
backing_inode_security(struct dentry * dentry)332 static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
333 {
334 	struct inode *inode = d_backing_inode(dentry);
335 
336 	__inode_security_revalidate(inode, dentry, true);
337 	return selinux_inode(inode);
338 }
339 
inode_free_security(struct inode * inode)340 static void inode_free_security(struct inode *inode)
341 {
342 	struct inode_security_struct *isec = selinux_inode(inode);
343 	struct superblock_security_struct *sbsec;
344 
345 	if (!isec)
346 		return;
347 	sbsec = selinux_superblock(inode->i_sb);
348 	/*
349 	 * As not all inode security structures are in a list, we check for
350 	 * empty list outside of the lock to make sure that we won't waste
351 	 * time taking a lock doing nothing.
352 	 *
353 	 * The list_del_init() function can be safely called more than once.
354 	 * It should not be possible for this function to be called with
355 	 * concurrent list_add(), but for better safety against future changes
356 	 * in the code, we use list_empty_careful() here.
357 	 */
358 	if (!list_empty_careful(&isec->list)) {
359 		spin_lock(&sbsec->isec_lock);
360 		list_del_init(&isec->list);
361 		spin_unlock(&sbsec->isec_lock);
362 	}
363 }
364 
365 struct selinux_mnt_opts {
366 	u32 fscontext_sid;
367 	u32 context_sid;
368 	u32 rootcontext_sid;
369 	u32 defcontext_sid;
370 };
371 
selinux_free_mnt_opts(void * mnt_opts)372 static void selinux_free_mnt_opts(void *mnt_opts)
373 {
374 	kfree(mnt_opts);
375 }
376 
377 enum {
378 	Opt_error = -1,
379 	Opt_context = 0,
380 	Opt_defcontext = 1,
381 	Opt_fscontext = 2,
382 	Opt_rootcontext = 3,
383 	Opt_seclabel = 4,
384 };
385 
386 #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg}
387 static const struct {
388 	const char *name;
389 	int len;
390 	int opt;
391 	bool has_arg;
392 } tokens[] = {
393 	A(context, true),
394 	A(fscontext, true),
395 	A(defcontext, true),
396 	A(rootcontext, true),
397 	A(seclabel, false),
398 };
399 #undef A
400 
match_opt_prefix(char * s,int l,char ** arg)401 static int match_opt_prefix(char *s, int l, char **arg)
402 {
403 	int i;
404 
405 	for (i = 0; i < ARRAY_SIZE(tokens); i++) {
406 		size_t len = tokens[i].len;
407 		if (len > l || memcmp(s, tokens[i].name, len))
408 			continue;
409 		if (tokens[i].has_arg) {
410 			if (len == l || s[len] != '=')
411 				continue;
412 			*arg = s + len + 1;
413 		} else if (len != l)
414 			continue;
415 		return tokens[i].opt;
416 	}
417 	return Opt_error;
418 }
419 
420 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
421 
may_context_mount_sb_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)422 static int may_context_mount_sb_relabel(u32 sid,
423 			struct superblock_security_struct *sbsec,
424 			const struct cred *cred)
425 {
426 	const struct task_security_struct *tsec = selinux_cred(cred);
427 	int rc;
428 
429 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
430 			  FILESYSTEM__RELABELFROM, NULL);
431 	if (rc)
432 		return rc;
433 
434 	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
435 			  FILESYSTEM__RELABELTO, NULL);
436 	return rc;
437 }
438 
may_context_mount_inode_relabel(u32 sid,struct superblock_security_struct * sbsec,const struct cred * cred)439 static int may_context_mount_inode_relabel(u32 sid,
440 			struct superblock_security_struct *sbsec,
441 			const struct cred *cred)
442 {
443 	const struct task_security_struct *tsec = selinux_cred(cred);
444 	int rc;
445 	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
446 			  FILESYSTEM__RELABELFROM, NULL);
447 	if (rc)
448 		return rc;
449 
450 	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
451 			  FILESYSTEM__ASSOCIATE, NULL);
452 	return rc;
453 }
454 
selinux_is_genfs_special_handling(struct super_block * sb)455 static int selinux_is_genfs_special_handling(struct super_block *sb)
456 {
457 	/* Special handling. Genfs but also in-core setxattr handler */
458 	return	!strcmp(sb->s_type->name, "sysfs") ||
459 		!strcmp(sb->s_type->name, "pstore") ||
460 		!strcmp(sb->s_type->name, "debugfs") ||
461 		!strcmp(sb->s_type->name, "tracefs") ||
462 		!strcmp(sb->s_type->name, "rootfs") ||
463 		(selinux_policycap_cgroupseclabel() &&
464 		 (!strcmp(sb->s_type->name, "cgroup") ||
465 		  !strcmp(sb->s_type->name, "cgroup2")));
466 }
467 
selinux_is_sblabel_mnt(struct super_block * sb)468 static int selinux_is_sblabel_mnt(struct super_block *sb)
469 {
470 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
471 
472 	/*
473 	 * IMPORTANT: Double-check logic in this function when adding a new
474 	 * SECURITY_FS_USE_* definition!
475 	 */
476 	BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7);
477 
478 	switch (sbsec->behavior) {
479 	case SECURITY_FS_USE_XATTR:
480 	case SECURITY_FS_USE_TRANS:
481 	case SECURITY_FS_USE_TASK:
482 	case SECURITY_FS_USE_NATIVE:
483 		return 1;
484 
485 	case SECURITY_FS_USE_GENFS:
486 		return selinux_is_genfs_special_handling(sb);
487 
488 	/* Never allow relabeling on context mounts */
489 	case SECURITY_FS_USE_MNTPOINT:
490 	case SECURITY_FS_USE_NONE:
491 	default:
492 		return 0;
493 	}
494 }
495 
sb_check_xattr_support(struct super_block * sb)496 static int sb_check_xattr_support(struct super_block *sb)
497 {
498 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
499 	struct dentry *root = sb->s_root;
500 	struct inode *root_inode = d_backing_inode(root);
501 	u32 sid;
502 	int rc;
503 
504 	/*
505 	 * Make sure that the xattr handler exists and that no
506 	 * error other than -ENODATA is returned by getxattr on
507 	 * the root directory.  -ENODATA is ok, as this may be
508 	 * the first boot of the SELinux kernel before we have
509 	 * assigned xattr values to the filesystem.
510 	 */
511 	if (!(root_inode->i_opflags & IOP_XATTR)) {
512 		pr_warn("SELinux: (dev %s, type %s) has no xattr support\n",
513 			sb->s_id, sb->s_type->name);
514 		goto fallback;
515 	}
516 
517 	rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
518 	if (rc < 0 && rc != -ENODATA) {
519 		if (rc == -EOPNOTSUPP) {
520 			pr_warn("SELinux: (dev %s, type %s) has no security xattr handler\n",
521 				sb->s_id, sb->s_type->name);
522 			goto fallback;
523 		} else {
524 			pr_warn("SELinux: (dev %s, type %s) getxattr errno %d\n",
525 				sb->s_id, sb->s_type->name, -rc);
526 			return rc;
527 		}
528 	}
529 	return 0;
530 
531 fallback:
532 	/* No xattr support - try to fallback to genfs if possible. */
533 	rc = security_genfs_sid(sb->s_type->name, "/",
534 				SECCLASS_DIR, &sid);
535 	if (rc)
536 		return -EOPNOTSUPP;
537 
538 	pr_warn("SELinux: (dev %s, type %s) falling back to genfs\n",
539 		sb->s_id, sb->s_type->name);
540 	sbsec->behavior = SECURITY_FS_USE_GENFS;
541 	sbsec->sid = sid;
542 	return 0;
543 }
544 
sb_finish_set_opts(struct super_block * sb)545 static int sb_finish_set_opts(struct super_block *sb)
546 {
547 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
548 	struct dentry *root = sb->s_root;
549 	struct inode *root_inode = d_backing_inode(root);
550 	int rc = 0;
551 
552 	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
553 		rc = sb_check_xattr_support(sb);
554 		if (rc)
555 			return rc;
556 	}
557 
558 	sbsec->flags |= SE_SBINITIALIZED;
559 
560 	/*
561 	 * Explicitly set or clear SBLABEL_MNT.  It's not sufficient to simply
562 	 * leave the flag untouched because sb_clone_mnt_opts might be handing
563 	 * us a superblock that needs the flag to be cleared.
564 	 */
565 	if (selinux_is_sblabel_mnt(sb))
566 		sbsec->flags |= SBLABEL_MNT;
567 	else
568 		sbsec->flags &= ~SBLABEL_MNT;
569 
570 	/* Initialize the root inode. */
571 	rc = inode_doinit_with_dentry(root_inode, root);
572 
573 	/* Initialize any other inodes associated with the superblock, e.g.
574 	   inodes created prior to initial policy load or inodes created
575 	   during get_sb by a pseudo filesystem that directly
576 	   populates itself. */
577 	spin_lock(&sbsec->isec_lock);
578 	while (!list_empty(&sbsec->isec_head)) {
579 		struct inode_security_struct *isec =
580 				list_first_entry(&sbsec->isec_head,
581 					   struct inode_security_struct, list);
582 		struct inode *inode = isec->inode;
583 		list_del_init(&isec->list);
584 		spin_unlock(&sbsec->isec_lock);
585 		inode = igrab(inode);
586 		if (inode) {
587 			if (!IS_PRIVATE(inode))
588 				inode_doinit_with_dentry(inode, NULL);
589 			iput(inode);
590 		}
591 		spin_lock(&sbsec->isec_lock);
592 	}
593 	spin_unlock(&sbsec->isec_lock);
594 	return rc;
595 }
596 
bad_option(struct superblock_security_struct * sbsec,char flag,u32 old_sid,u32 new_sid)597 static int bad_option(struct superblock_security_struct *sbsec, char flag,
598 		      u32 old_sid, u32 new_sid)
599 {
600 	char mnt_flags = sbsec->flags & SE_MNTMASK;
601 
602 	/* check if the old mount command had the same options */
603 	if (sbsec->flags & SE_SBINITIALIZED)
604 		if (!(sbsec->flags & flag) ||
605 		    (old_sid != new_sid))
606 			return 1;
607 
608 	/* check if we were passed the same options twice,
609 	 * aka someone passed context=a,context=b
610 	 */
611 	if (!(sbsec->flags & SE_SBINITIALIZED))
612 		if (mnt_flags & flag)
613 			return 1;
614 	return 0;
615 }
616 
617 /*
618  * Allow filesystems with binary mount data to explicitly set mount point
619  * labeling information.
620  */
selinux_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)621 static int selinux_set_mnt_opts(struct super_block *sb,
622 				void *mnt_opts,
623 				unsigned long kern_flags,
624 				unsigned long *set_kern_flags)
625 {
626 	const struct cred *cred = current_cred();
627 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
628 	struct dentry *root = sb->s_root;
629 	struct selinux_mnt_opts *opts = mnt_opts;
630 	struct inode_security_struct *root_isec;
631 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
632 	u32 defcontext_sid = 0;
633 	int rc = 0;
634 
635 	/*
636 	 * Specifying internal flags without providing a place to
637 	 * place the results is not allowed
638 	 */
639 	if (kern_flags && !set_kern_flags)
640 		return -EINVAL;
641 
642 	mutex_lock(&sbsec->lock);
643 
644 	if (!selinux_initialized()) {
645 		if (!opts) {
646 			/* Defer initialization until selinux_complete_init,
647 			   after the initial policy is loaded and the security
648 			   server is ready to handle calls. */
649 			if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
650 				sbsec->flags |= SE_SBNATIVE;
651 				*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
652 			}
653 			goto out;
654 		}
655 		rc = -EINVAL;
656 		pr_warn("SELinux: Unable to set superblock options "
657 			"before the security server is initialized\n");
658 		goto out;
659 	}
660 
661 	/*
662 	 * Binary mount data FS will come through this function twice.  Once
663 	 * from an explicit call and once from the generic calls from the vfs.
664 	 * Since the generic VFS calls will not contain any security mount data
665 	 * we need to skip the double mount verification.
666 	 *
667 	 * This does open a hole in which we will not notice if the first
668 	 * mount using this sb set explicit options and a second mount using
669 	 * this sb does not set any security options.  (The first options
670 	 * will be used for both mounts)
671 	 */
672 	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
673 	    && !opts)
674 		goto out;
675 
676 	root_isec = backing_inode_security_novalidate(root);
677 
678 	/*
679 	 * parse the mount options, check if they are valid sids.
680 	 * also check if someone is trying to mount the same sb more
681 	 * than once with different security options.
682 	 */
683 	if (opts) {
684 		if (opts->fscontext_sid) {
685 			fscontext_sid = opts->fscontext_sid;
686 			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
687 					fscontext_sid))
688 				goto out_double_mount;
689 			sbsec->flags |= FSCONTEXT_MNT;
690 		}
691 		if (opts->context_sid) {
692 			context_sid = opts->context_sid;
693 			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
694 					context_sid))
695 				goto out_double_mount;
696 			sbsec->flags |= CONTEXT_MNT;
697 		}
698 		if (opts->rootcontext_sid) {
699 			rootcontext_sid = opts->rootcontext_sid;
700 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
701 					rootcontext_sid))
702 				goto out_double_mount;
703 			sbsec->flags |= ROOTCONTEXT_MNT;
704 		}
705 		if (opts->defcontext_sid) {
706 			defcontext_sid = opts->defcontext_sid;
707 			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
708 					defcontext_sid))
709 				goto out_double_mount;
710 			sbsec->flags |= DEFCONTEXT_MNT;
711 		}
712 	}
713 
714 	if (sbsec->flags & SE_SBINITIALIZED) {
715 		/* previously mounted with options, but not on this attempt? */
716 		if ((sbsec->flags & SE_MNTMASK) && !opts)
717 			goto out_double_mount;
718 		rc = 0;
719 		goto out;
720 	}
721 
722 	if (strcmp(sb->s_type->name, "proc") == 0)
723 		sbsec->flags |= SE_SBPROC | SE_SBGENFS;
724 
725 	if (!strcmp(sb->s_type->name, "debugfs") ||
726 	    !strcmp(sb->s_type->name, "tracefs") ||
727 	    !strcmp(sb->s_type->name, "binder") ||
728 	    !strcmp(sb->s_type->name, "bpf") ||
729 	    !strcmp(sb->s_type->name, "pstore") ||
730 	    !strcmp(sb->s_type->name, "securityfs"))
731 		sbsec->flags |= SE_SBGENFS;
732 
733 	if (!strcmp(sb->s_type->name, "sysfs") ||
734 	    !strcmp(sb->s_type->name, "cgroup") ||
735 	    !strcmp(sb->s_type->name, "cgroup2"))
736 		sbsec->flags |= SE_SBGENFS | SE_SBGENFS_XATTR;
737 
738 	if (!sbsec->behavior) {
739 		/*
740 		 * Determine the labeling behavior to use for this
741 		 * filesystem type.
742 		 */
743 		rc = security_fs_use(sb);
744 		if (rc) {
745 			pr_warn("%s: security_fs_use(%s) returned %d\n",
746 					__func__, sb->s_type->name, rc);
747 			goto out;
748 		}
749 	}
750 
751 	/*
752 	 * If this is a user namespace mount and the filesystem type is not
753 	 * explicitly whitelisted, then no contexts are allowed on the command
754 	 * line and security labels must be ignored.
755 	 */
756 	if (sb->s_user_ns != &init_user_ns &&
757 	    strcmp(sb->s_type->name, "tmpfs") &&
758 	    strcmp(sb->s_type->name, "ramfs") &&
759 	    strcmp(sb->s_type->name, "devpts") &&
760 	    strcmp(sb->s_type->name, "overlay")) {
761 		if (context_sid || fscontext_sid || rootcontext_sid ||
762 		    defcontext_sid) {
763 			rc = -EACCES;
764 			goto out;
765 		}
766 		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
767 			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
768 			rc = security_transition_sid(current_sid(),
769 						     current_sid(),
770 						     SECCLASS_FILE, NULL,
771 						     &sbsec->mntpoint_sid);
772 			if (rc)
773 				goto out;
774 		}
775 		goto out_set_opts;
776 	}
777 
778 	/* sets the context of the superblock for the fs being mounted. */
779 	if (fscontext_sid) {
780 		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
781 		if (rc)
782 			goto out;
783 
784 		sbsec->sid = fscontext_sid;
785 	}
786 
787 	/*
788 	 * Switch to using mount point labeling behavior.
789 	 * sets the label used on all file below the mountpoint, and will set
790 	 * the superblock context if not already set.
791 	 */
792 	if (sbsec->flags & SE_SBNATIVE) {
793 		/*
794 		 * This means we are initializing a superblock that has been
795 		 * mounted before the SELinux was initialized and the
796 		 * filesystem requested native labeling. We had already
797 		 * returned SECURITY_LSM_NATIVE_LABELS in *set_kern_flags
798 		 * in the original mount attempt, so now we just need to set
799 		 * the SECURITY_FS_USE_NATIVE behavior.
800 		 */
801 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
802 	} else if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
803 		sbsec->behavior = SECURITY_FS_USE_NATIVE;
804 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
805 	}
806 
807 	if (context_sid) {
808 		if (!fscontext_sid) {
809 			rc = may_context_mount_sb_relabel(context_sid, sbsec,
810 							  cred);
811 			if (rc)
812 				goto out;
813 			sbsec->sid = context_sid;
814 		} else {
815 			rc = may_context_mount_inode_relabel(context_sid, sbsec,
816 							     cred);
817 			if (rc)
818 				goto out;
819 		}
820 		if (!rootcontext_sid)
821 			rootcontext_sid = context_sid;
822 
823 		sbsec->mntpoint_sid = context_sid;
824 		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
825 	}
826 
827 	if (rootcontext_sid) {
828 		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
829 						     cred);
830 		if (rc)
831 			goto out;
832 
833 		root_isec->sid = rootcontext_sid;
834 		root_isec->initialized = LABEL_INITIALIZED;
835 	}
836 
837 	if (defcontext_sid) {
838 		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
839 			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
840 			rc = -EINVAL;
841 			pr_warn("SELinux: defcontext option is "
842 			       "invalid for this filesystem type\n");
843 			goto out;
844 		}
845 
846 		if (defcontext_sid != sbsec->def_sid) {
847 			rc = may_context_mount_inode_relabel(defcontext_sid,
848 							     sbsec, cred);
849 			if (rc)
850 				goto out;
851 		}
852 
853 		sbsec->def_sid = defcontext_sid;
854 	}
855 
856 out_set_opts:
857 	rc = sb_finish_set_opts(sb);
858 out:
859 	mutex_unlock(&sbsec->lock);
860 	return rc;
861 out_double_mount:
862 	rc = -EINVAL;
863 	pr_warn("SELinux: mount invalid.  Same superblock, different "
864 	       "security settings for (dev %s, type %s)\n", sb->s_id,
865 	       sb->s_type->name);
866 	goto out;
867 }
868 
selinux_cmp_sb_context(const struct super_block * oldsb,const struct super_block * newsb)869 static int selinux_cmp_sb_context(const struct super_block *oldsb,
870 				    const struct super_block *newsb)
871 {
872 	struct superblock_security_struct *old = selinux_superblock(oldsb);
873 	struct superblock_security_struct *new = selinux_superblock(newsb);
874 	char oldflags = old->flags & SE_MNTMASK;
875 	char newflags = new->flags & SE_MNTMASK;
876 
877 	if (oldflags != newflags)
878 		goto mismatch;
879 	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
880 		goto mismatch;
881 	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
882 		goto mismatch;
883 	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
884 		goto mismatch;
885 	if (oldflags & ROOTCONTEXT_MNT) {
886 		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
887 		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
888 		if (oldroot->sid != newroot->sid)
889 			goto mismatch;
890 	}
891 	return 0;
892 mismatch:
893 	pr_warn("SELinux: mount invalid.  Same superblock, "
894 			    "different security settings for (dev %s, "
895 			    "type %s)\n", newsb->s_id, newsb->s_type->name);
896 	return -EBUSY;
897 }
898 
selinux_sb_clone_mnt_opts(const struct super_block * oldsb,struct super_block * newsb,unsigned long kern_flags,unsigned long * set_kern_flags)899 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
900 					struct super_block *newsb,
901 					unsigned long kern_flags,
902 					unsigned long *set_kern_flags)
903 {
904 	int rc = 0;
905 	const struct superblock_security_struct *oldsbsec =
906 						selinux_superblock(oldsb);
907 	struct superblock_security_struct *newsbsec = selinux_superblock(newsb);
908 
909 	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
910 	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
911 	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
912 
913 	/*
914 	 * Specifying internal flags without providing a place to
915 	 * place the results is not allowed.
916 	 */
917 	if (kern_flags && !set_kern_flags)
918 		return -EINVAL;
919 
920 	mutex_lock(&newsbsec->lock);
921 
922 	/*
923 	 * if the parent was able to be mounted it clearly had no special lsm
924 	 * mount options.  thus we can safely deal with this superblock later
925 	 */
926 	if (!selinux_initialized()) {
927 		if (kern_flags & SECURITY_LSM_NATIVE_LABELS) {
928 			newsbsec->flags |= SE_SBNATIVE;
929 			*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
930 		}
931 		goto out;
932 	}
933 
934 	/* how can we clone if the old one wasn't set up?? */
935 	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
936 
937 	/* if fs is reusing a sb, make sure that the contexts match */
938 	if (newsbsec->flags & SE_SBINITIALIZED) {
939 		mutex_unlock(&newsbsec->lock);
940 		if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context)
941 			*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
942 		return selinux_cmp_sb_context(oldsb, newsb);
943 	}
944 
945 	newsbsec->flags = oldsbsec->flags;
946 
947 	newsbsec->sid = oldsbsec->sid;
948 	newsbsec->def_sid = oldsbsec->def_sid;
949 	newsbsec->behavior = oldsbsec->behavior;
950 
951 	if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
952 		!(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
953 		rc = security_fs_use(newsb);
954 		if (rc)
955 			goto out;
956 	}
957 
958 	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
959 		newsbsec->behavior = SECURITY_FS_USE_NATIVE;
960 		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
961 	}
962 
963 	if (set_context) {
964 		u32 sid = oldsbsec->mntpoint_sid;
965 
966 		if (!set_fscontext)
967 			newsbsec->sid = sid;
968 		if (!set_rootcontext) {
969 			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
970 			newisec->sid = sid;
971 		}
972 		newsbsec->mntpoint_sid = sid;
973 	}
974 	if (set_rootcontext) {
975 		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
976 		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
977 
978 		newisec->sid = oldisec->sid;
979 	}
980 
981 	sb_finish_set_opts(newsb);
982 out:
983 	mutex_unlock(&newsbsec->lock);
984 	return rc;
985 }
986 
987 /*
988  * NOTE: the caller is responsible for freeing the memory even if on error.
989  */
selinux_add_opt(int token,const char * s,void ** mnt_opts)990 static int selinux_add_opt(int token, const char *s, void **mnt_opts)
991 {
992 	struct selinux_mnt_opts *opts = *mnt_opts;
993 	u32 *dst_sid;
994 	int rc;
995 
996 	if (token == Opt_seclabel)
997 		/* eaten and completely ignored */
998 		return 0;
999 	if (!s)
1000 		return -EINVAL;
1001 
1002 	if (!selinux_initialized()) {
1003 		pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n");
1004 		return -EINVAL;
1005 	}
1006 
1007 	if (!opts) {
1008 		opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1009 		if (!opts)
1010 			return -ENOMEM;
1011 		*mnt_opts = opts;
1012 	}
1013 
1014 	switch (token) {
1015 	case Opt_context:
1016 		if (opts->context_sid || opts->defcontext_sid)
1017 			goto err;
1018 		dst_sid = &opts->context_sid;
1019 		break;
1020 	case Opt_fscontext:
1021 		if (opts->fscontext_sid)
1022 			goto err;
1023 		dst_sid = &opts->fscontext_sid;
1024 		break;
1025 	case Opt_rootcontext:
1026 		if (opts->rootcontext_sid)
1027 			goto err;
1028 		dst_sid = &opts->rootcontext_sid;
1029 		break;
1030 	case Opt_defcontext:
1031 		if (opts->context_sid || opts->defcontext_sid)
1032 			goto err;
1033 		dst_sid = &opts->defcontext_sid;
1034 		break;
1035 	default:
1036 		WARN_ON(1);
1037 		return -EINVAL;
1038 	}
1039 	rc = security_context_str_to_sid(s, dst_sid, GFP_KERNEL);
1040 	if (rc)
1041 		pr_warn("SELinux: security_context_str_to_sid (%s) failed with errno=%d\n",
1042 			s, rc);
1043 	return rc;
1044 
1045 err:
1046 	pr_warn(SEL_MOUNT_FAIL_MSG);
1047 	return -EINVAL;
1048 }
1049 
show_sid(struct seq_file * m,u32 sid)1050 static int show_sid(struct seq_file *m, u32 sid)
1051 {
1052 	char *context = NULL;
1053 	u32 len;
1054 	int rc;
1055 
1056 	rc = security_sid_to_context(sid, &context, &len);
1057 	if (!rc) {
1058 		bool has_comma = strchr(context, ',');
1059 
1060 		seq_putc(m, '=');
1061 		if (has_comma)
1062 			seq_putc(m, '\"');
1063 		seq_escape(m, context, "\"\n\\");
1064 		if (has_comma)
1065 			seq_putc(m, '\"');
1066 	}
1067 	kfree(context);
1068 	return rc;
1069 }
1070 
selinux_sb_show_options(struct seq_file * m,struct super_block * sb)1071 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1072 {
1073 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
1074 	int rc;
1075 
1076 	if (!(sbsec->flags & SE_SBINITIALIZED))
1077 		return 0;
1078 
1079 	if (!selinux_initialized())
1080 		return 0;
1081 
1082 	if (sbsec->flags & FSCONTEXT_MNT) {
1083 		seq_putc(m, ',');
1084 		seq_puts(m, FSCONTEXT_STR);
1085 		rc = show_sid(m, sbsec->sid);
1086 		if (rc)
1087 			return rc;
1088 	}
1089 	if (sbsec->flags & CONTEXT_MNT) {
1090 		seq_putc(m, ',');
1091 		seq_puts(m, CONTEXT_STR);
1092 		rc = show_sid(m, sbsec->mntpoint_sid);
1093 		if (rc)
1094 			return rc;
1095 	}
1096 	if (sbsec->flags & DEFCONTEXT_MNT) {
1097 		seq_putc(m, ',');
1098 		seq_puts(m, DEFCONTEXT_STR);
1099 		rc = show_sid(m, sbsec->def_sid);
1100 		if (rc)
1101 			return rc;
1102 	}
1103 	if (sbsec->flags & ROOTCONTEXT_MNT) {
1104 		struct dentry *root = sb->s_root;
1105 		struct inode_security_struct *isec = backing_inode_security(root);
1106 		seq_putc(m, ',');
1107 		seq_puts(m, ROOTCONTEXT_STR);
1108 		rc = show_sid(m, isec->sid);
1109 		if (rc)
1110 			return rc;
1111 	}
1112 	if (sbsec->flags & SBLABEL_MNT) {
1113 		seq_putc(m, ',');
1114 		seq_puts(m, SECLABEL_STR);
1115 	}
1116 	return 0;
1117 }
1118 
inode_mode_to_security_class(umode_t mode)1119 static inline u16 inode_mode_to_security_class(umode_t mode)
1120 {
1121 	switch (mode & S_IFMT) {
1122 	case S_IFSOCK:
1123 		return SECCLASS_SOCK_FILE;
1124 	case S_IFLNK:
1125 		return SECCLASS_LNK_FILE;
1126 	case S_IFREG:
1127 		return SECCLASS_FILE;
1128 	case S_IFBLK:
1129 		return SECCLASS_BLK_FILE;
1130 	case S_IFDIR:
1131 		return SECCLASS_DIR;
1132 	case S_IFCHR:
1133 		return SECCLASS_CHR_FILE;
1134 	case S_IFIFO:
1135 		return SECCLASS_FIFO_FILE;
1136 
1137 	}
1138 
1139 	return SECCLASS_FILE;
1140 }
1141 
default_protocol_stream(int protocol)1142 static inline int default_protocol_stream(int protocol)
1143 {
1144 	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP ||
1145 		protocol == IPPROTO_MPTCP);
1146 }
1147 
default_protocol_dgram(int protocol)1148 static inline int default_protocol_dgram(int protocol)
1149 {
1150 	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1151 }
1152 
socket_type_to_security_class(int family,int type,int protocol)1153 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1154 {
1155 	bool extsockclass = selinux_policycap_extsockclass();
1156 
1157 	switch (family) {
1158 	case PF_UNIX:
1159 		switch (type) {
1160 		case SOCK_STREAM:
1161 		case SOCK_SEQPACKET:
1162 			return SECCLASS_UNIX_STREAM_SOCKET;
1163 		case SOCK_DGRAM:
1164 		case SOCK_RAW:
1165 			return SECCLASS_UNIX_DGRAM_SOCKET;
1166 		}
1167 		break;
1168 	case PF_INET:
1169 	case PF_INET6:
1170 		switch (type) {
1171 		case SOCK_STREAM:
1172 		case SOCK_SEQPACKET:
1173 			if (default_protocol_stream(protocol))
1174 				return SECCLASS_TCP_SOCKET;
1175 			else if (extsockclass && protocol == IPPROTO_SCTP)
1176 				return SECCLASS_SCTP_SOCKET;
1177 			else
1178 				return SECCLASS_RAWIP_SOCKET;
1179 		case SOCK_DGRAM:
1180 			if (default_protocol_dgram(protocol))
1181 				return SECCLASS_UDP_SOCKET;
1182 			else if (extsockclass && (protocol == IPPROTO_ICMP ||
1183 						  protocol == IPPROTO_ICMPV6))
1184 				return SECCLASS_ICMP_SOCKET;
1185 			else
1186 				return SECCLASS_RAWIP_SOCKET;
1187 		case SOCK_DCCP:
1188 			return SECCLASS_DCCP_SOCKET;
1189 		default:
1190 			return SECCLASS_RAWIP_SOCKET;
1191 		}
1192 		break;
1193 	case PF_NETLINK:
1194 		switch (protocol) {
1195 		case NETLINK_ROUTE:
1196 			return SECCLASS_NETLINK_ROUTE_SOCKET;
1197 		case NETLINK_SOCK_DIAG:
1198 			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1199 		case NETLINK_NFLOG:
1200 			return SECCLASS_NETLINK_NFLOG_SOCKET;
1201 		case NETLINK_XFRM:
1202 			return SECCLASS_NETLINK_XFRM_SOCKET;
1203 		case NETLINK_SELINUX:
1204 			return SECCLASS_NETLINK_SELINUX_SOCKET;
1205 		case NETLINK_ISCSI:
1206 			return SECCLASS_NETLINK_ISCSI_SOCKET;
1207 		case NETLINK_AUDIT:
1208 			return SECCLASS_NETLINK_AUDIT_SOCKET;
1209 		case NETLINK_FIB_LOOKUP:
1210 			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
1211 		case NETLINK_CONNECTOR:
1212 			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
1213 		case NETLINK_NETFILTER:
1214 			return SECCLASS_NETLINK_NETFILTER_SOCKET;
1215 		case NETLINK_DNRTMSG:
1216 			return SECCLASS_NETLINK_DNRT_SOCKET;
1217 		case NETLINK_KOBJECT_UEVENT:
1218 			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1219 		case NETLINK_GENERIC:
1220 			return SECCLASS_NETLINK_GENERIC_SOCKET;
1221 		case NETLINK_SCSITRANSPORT:
1222 			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
1223 		case NETLINK_RDMA:
1224 			return SECCLASS_NETLINK_RDMA_SOCKET;
1225 		case NETLINK_CRYPTO:
1226 			return SECCLASS_NETLINK_CRYPTO_SOCKET;
1227 		default:
1228 			return SECCLASS_NETLINK_SOCKET;
1229 		}
1230 	case PF_PACKET:
1231 		return SECCLASS_PACKET_SOCKET;
1232 	case PF_KEY:
1233 		return SECCLASS_KEY_SOCKET;
1234 	case PF_APPLETALK:
1235 		return SECCLASS_APPLETALK_SOCKET;
1236 	}
1237 
1238 	if (extsockclass) {
1239 		switch (family) {
1240 		case PF_AX25:
1241 			return SECCLASS_AX25_SOCKET;
1242 		case PF_IPX:
1243 			return SECCLASS_IPX_SOCKET;
1244 		case PF_NETROM:
1245 			return SECCLASS_NETROM_SOCKET;
1246 		case PF_ATMPVC:
1247 			return SECCLASS_ATMPVC_SOCKET;
1248 		case PF_X25:
1249 			return SECCLASS_X25_SOCKET;
1250 		case PF_ROSE:
1251 			return SECCLASS_ROSE_SOCKET;
1252 		case PF_DECnet:
1253 			return SECCLASS_DECNET_SOCKET;
1254 		case PF_ATMSVC:
1255 			return SECCLASS_ATMSVC_SOCKET;
1256 		case PF_RDS:
1257 			return SECCLASS_RDS_SOCKET;
1258 		case PF_IRDA:
1259 			return SECCLASS_IRDA_SOCKET;
1260 		case PF_PPPOX:
1261 			return SECCLASS_PPPOX_SOCKET;
1262 		case PF_LLC:
1263 			return SECCLASS_LLC_SOCKET;
1264 		case PF_CAN:
1265 			return SECCLASS_CAN_SOCKET;
1266 		case PF_TIPC:
1267 			return SECCLASS_TIPC_SOCKET;
1268 		case PF_BLUETOOTH:
1269 			return SECCLASS_BLUETOOTH_SOCKET;
1270 		case PF_IUCV:
1271 			return SECCLASS_IUCV_SOCKET;
1272 		case PF_RXRPC:
1273 			return SECCLASS_RXRPC_SOCKET;
1274 		case PF_ISDN:
1275 			return SECCLASS_ISDN_SOCKET;
1276 		case PF_PHONET:
1277 			return SECCLASS_PHONET_SOCKET;
1278 		case PF_IEEE802154:
1279 			return SECCLASS_IEEE802154_SOCKET;
1280 		case PF_CAIF:
1281 			return SECCLASS_CAIF_SOCKET;
1282 		case PF_ALG:
1283 			return SECCLASS_ALG_SOCKET;
1284 		case PF_NFC:
1285 			return SECCLASS_NFC_SOCKET;
1286 		case PF_VSOCK:
1287 			return SECCLASS_VSOCK_SOCKET;
1288 		case PF_KCM:
1289 			return SECCLASS_KCM_SOCKET;
1290 		case PF_QIPCRTR:
1291 			return SECCLASS_QIPCRTR_SOCKET;
1292 		case PF_SMC:
1293 			return SECCLASS_SMC_SOCKET;
1294 		case PF_XDP:
1295 			return SECCLASS_XDP_SOCKET;
1296 		case PF_MCTP:
1297 			return SECCLASS_MCTP_SOCKET;
1298 #if PF_MAX > 46
1299 #error New address family defined, please update this function.
1300 #endif
1301 		}
1302 	}
1303 
1304 	return SECCLASS_SOCKET;
1305 }
1306 
selinux_genfs_get_sid(struct dentry * dentry,u16 tclass,u16 flags,u32 * sid)1307 static int selinux_genfs_get_sid(struct dentry *dentry,
1308 				 u16 tclass,
1309 				 u16 flags,
1310 				 u32 *sid)
1311 {
1312 	int rc;
1313 	struct super_block *sb = dentry->d_sb;
1314 	char *buffer, *path;
1315 
1316 	buffer = (char *)__get_free_page(GFP_KERNEL);
1317 	if (!buffer)
1318 		return -ENOMEM;
1319 
1320 	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1321 	if (IS_ERR(path))
1322 		rc = PTR_ERR(path);
1323 	else {
1324 		if (flags & SE_SBPROC) {
1325 			/* each process gets a /proc/PID/ entry. Strip off the
1326 			 * PID part to get a valid selinux labeling.
1327 			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1328 			while (path[1] >= '0' && path[1] <= '9') {
1329 				path[1] = '/';
1330 				path++;
1331 			}
1332 		}
1333 		rc = security_genfs_sid(sb->s_type->name,
1334 					path, tclass, sid);
1335 		if (rc == -ENOENT) {
1336 			/* No match in policy, mark as unlabeled. */
1337 			*sid = SECINITSID_UNLABELED;
1338 			rc = 0;
1339 		}
1340 	}
1341 	free_page((unsigned long)buffer);
1342 	return rc;
1343 }
1344 
inode_doinit_use_xattr(struct inode * inode,struct dentry * dentry,u32 def_sid,u32 * sid)1345 static int inode_doinit_use_xattr(struct inode *inode, struct dentry *dentry,
1346 				  u32 def_sid, u32 *sid)
1347 {
1348 #define INITCONTEXTLEN 255
1349 	char *context;
1350 	unsigned int len;
1351 	int rc;
1352 
1353 	len = INITCONTEXTLEN;
1354 	context = kmalloc(len + 1, GFP_NOFS);
1355 	if (!context)
1356 		return -ENOMEM;
1357 
1358 	context[len] = '\0';
1359 	rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
1360 	if (rc == -ERANGE) {
1361 		kfree(context);
1362 
1363 		/* Need a larger buffer.  Query for the right size. */
1364 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
1365 		if (rc < 0)
1366 			return rc;
1367 
1368 		len = rc;
1369 		context = kmalloc(len + 1, GFP_NOFS);
1370 		if (!context)
1371 			return -ENOMEM;
1372 
1373 		context[len] = '\0';
1374 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX,
1375 				    context, len);
1376 	}
1377 	if (rc < 0) {
1378 		kfree(context);
1379 		if (rc != -ENODATA) {
1380 			pr_warn("SELinux: %s:  getxattr returned %d for dev=%s ino=%ld\n",
1381 				__func__, -rc, inode->i_sb->s_id, inode->i_ino);
1382 			return rc;
1383 		}
1384 		*sid = def_sid;
1385 		return 0;
1386 	}
1387 
1388 	rc = security_context_to_sid_default(context, rc, sid,
1389 					     def_sid, GFP_NOFS);
1390 	if (rc) {
1391 		char *dev = inode->i_sb->s_id;
1392 		unsigned long ino = inode->i_ino;
1393 
1394 		if (rc == -EINVAL) {
1395 			pr_notice_ratelimited("SELinux: inode=%lu on dev=%s was found to have an invalid context=%s.  This indicates you may need to relabel the inode or the filesystem in question.\n",
1396 					      ino, dev, context);
1397 		} else {
1398 			pr_warn("SELinux: %s:  context_to_sid(%s) returned %d for dev=%s ino=%ld\n",
1399 				__func__, context, -rc, dev, ino);
1400 		}
1401 	}
1402 	kfree(context);
1403 	return 0;
1404 }
1405 
1406 /* The inode's security attributes must be initialized before first use. */
inode_doinit_with_dentry(struct inode * inode,struct dentry * opt_dentry)1407 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1408 {
1409 	struct superblock_security_struct *sbsec = NULL;
1410 	struct inode_security_struct *isec = selinux_inode(inode);
1411 	u32 task_sid, sid = 0;
1412 	u16 sclass;
1413 	struct dentry *dentry;
1414 	int rc = 0;
1415 
1416 	if (isec->initialized == LABEL_INITIALIZED)
1417 		return 0;
1418 
1419 	spin_lock(&isec->lock);
1420 	if (isec->initialized == LABEL_INITIALIZED)
1421 		goto out_unlock;
1422 
1423 	if (isec->sclass == SECCLASS_FILE)
1424 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1425 
1426 	sbsec = selinux_superblock(inode->i_sb);
1427 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
1428 		/* Defer initialization until selinux_complete_init,
1429 		   after the initial policy is loaded and the security
1430 		   server is ready to handle calls. */
1431 		spin_lock(&sbsec->isec_lock);
1432 		if (list_empty(&isec->list))
1433 			list_add(&isec->list, &sbsec->isec_head);
1434 		spin_unlock(&sbsec->isec_lock);
1435 		goto out_unlock;
1436 	}
1437 
1438 	sclass = isec->sclass;
1439 	task_sid = isec->task_sid;
1440 	sid = isec->sid;
1441 	isec->initialized = LABEL_PENDING;
1442 	spin_unlock(&isec->lock);
1443 
1444 	switch (sbsec->behavior) {
1445 	/*
1446 	 * In case of SECURITY_FS_USE_NATIVE we need to re-fetch the labels
1447 	 * via xattr when called from delayed_superblock_init().
1448 	 */
1449 	case SECURITY_FS_USE_NATIVE:
1450 	case SECURITY_FS_USE_XATTR:
1451 		if (!(inode->i_opflags & IOP_XATTR)) {
1452 			sid = sbsec->def_sid;
1453 			break;
1454 		}
1455 		/* Need a dentry, since the xattr API requires one.
1456 		   Life would be simpler if we could just pass the inode. */
1457 		if (opt_dentry) {
1458 			/* Called from d_instantiate or d_splice_alias. */
1459 			dentry = dget(opt_dentry);
1460 		} else {
1461 			/*
1462 			 * Called from selinux_complete_init, try to find a dentry.
1463 			 * Some filesystems really want a connected one, so try
1464 			 * that first.  We could split SECURITY_FS_USE_XATTR in
1465 			 * two, depending upon that...
1466 			 */
1467 			dentry = d_find_alias(inode);
1468 			if (!dentry)
1469 				dentry = d_find_any_alias(inode);
1470 		}
1471 		if (!dentry) {
1472 			/*
1473 			 * this is can be hit on boot when a file is accessed
1474 			 * before the policy is loaded.  When we load policy we
1475 			 * may find inodes that have no dentry on the
1476 			 * sbsec->isec_head list.  No reason to complain as these
1477 			 * will get fixed up the next time we go through
1478 			 * inode_doinit with a dentry, before these inodes could
1479 			 * be used again by userspace.
1480 			 */
1481 			goto out_invalid;
1482 		}
1483 
1484 		rc = inode_doinit_use_xattr(inode, dentry, sbsec->def_sid,
1485 					    &sid);
1486 		dput(dentry);
1487 		if (rc)
1488 			goto out;
1489 		break;
1490 	case SECURITY_FS_USE_TASK:
1491 		sid = task_sid;
1492 		break;
1493 	case SECURITY_FS_USE_TRANS:
1494 		/* Default to the fs SID. */
1495 		sid = sbsec->sid;
1496 
1497 		/* Try to obtain a transition SID. */
1498 		rc = security_transition_sid(task_sid, sid,
1499 					     sclass, NULL, &sid);
1500 		if (rc)
1501 			goto out;
1502 		break;
1503 	case SECURITY_FS_USE_MNTPOINT:
1504 		sid = sbsec->mntpoint_sid;
1505 		break;
1506 	default:
1507 		/* Default to the fs superblock SID. */
1508 		sid = sbsec->sid;
1509 
1510 		if ((sbsec->flags & SE_SBGENFS) &&
1511 		     (!S_ISLNK(inode->i_mode) ||
1512 		      selinux_policycap_genfs_seclabel_symlinks())) {
1513 			/* We must have a dentry to determine the label on
1514 			 * procfs inodes */
1515 			if (opt_dentry) {
1516 				/* Called from d_instantiate or
1517 				 * d_splice_alias. */
1518 				dentry = dget(opt_dentry);
1519 			} else {
1520 				/* Called from selinux_complete_init, try to
1521 				 * find a dentry.  Some filesystems really want
1522 				 * a connected one, so try that first.
1523 				 */
1524 				dentry = d_find_alias(inode);
1525 				if (!dentry)
1526 					dentry = d_find_any_alias(inode);
1527 			}
1528 			/*
1529 			 * This can be hit on boot when a file is accessed
1530 			 * before the policy is loaded.  When we load policy we
1531 			 * may find inodes that have no dentry on the
1532 			 * sbsec->isec_head list.  No reason to complain as
1533 			 * these will get fixed up the next time we go through
1534 			 * inode_doinit() with a dentry, before these inodes
1535 			 * could be used again by userspace.
1536 			 */
1537 			if (!dentry)
1538 				goto out_invalid;
1539 			rc = selinux_genfs_get_sid(dentry, sclass,
1540 						   sbsec->flags, &sid);
1541 			if (rc) {
1542 				dput(dentry);
1543 				goto out;
1544 			}
1545 
1546 			if ((sbsec->flags & SE_SBGENFS_XATTR) &&
1547 			    (inode->i_opflags & IOP_XATTR)) {
1548 				rc = inode_doinit_use_xattr(inode, dentry,
1549 							    sid, &sid);
1550 				if (rc) {
1551 					dput(dentry);
1552 					goto out;
1553 				}
1554 			}
1555 			dput(dentry);
1556 		}
1557 		break;
1558 	}
1559 
1560 out:
1561 	spin_lock(&isec->lock);
1562 	if (isec->initialized == LABEL_PENDING) {
1563 		if (rc) {
1564 			isec->initialized = LABEL_INVALID;
1565 			goto out_unlock;
1566 		}
1567 		isec->initialized = LABEL_INITIALIZED;
1568 		isec->sid = sid;
1569 	}
1570 
1571 out_unlock:
1572 	spin_unlock(&isec->lock);
1573 	return rc;
1574 
1575 out_invalid:
1576 	spin_lock(&isec->lock);
1577 	if (isec->initialized == LABEL_PENDING) {
1578 		isec->initialized = LABEL_INVALID;
1579 		isec->sid = sid;
1580 	}
1581 	spin_unlock(&isec->lock);
1582 	return 0;
1583 }
1584 
1585 /* Convert a Linux signal to an access vector. */
signal_to_av(int sig)1586 static inline u32 signal_to_av(int sig)
1587 {
1588 	u32 perm = 0;
1589 
1590 	switch (sig) {
1591 	case SIGCHLD:
1592 		/* Commonly granted from child to parent. */
1593 		perm = PROCESS__SIGCHLD;
1594 		break;
1595 	case SIGKILL:
1596 		/* Cannot be caught or ignored */
1597 		perm = PROCESS__SIGKILL;
1598 		break;
1599 	case SIGSTOP:
1600 		/* Cannot be caught or ignored */
1601 		perm = PROCESS__SIGSTOP;
1602 		break;
1603 	default:
1604 		/* All other signals. */
1605 		perm = PROCESS__SIGNAL;
1606 		break;
1607 	}
1608 
1609 	return perm;
1610 }
1611 
1612 #if CAP_LAST_CAP > 63
1613 #error Fix SELinux to handle capabilities > 63.
1614 #endif
1615 
1616 /* Check whether a task is allowed to use a capability. */
cred_has_capability(const struct cred * cred,int cap,unsigned int opts,bool initns)1617 static int cred_has_capability(const struct cred *cred,
1618 			       int cap, unsigned int opts, bool initns)
1619 {
1620 	struct common_audit_data ad;
1621 	struct av_decision avd;
1622 	u16 sclass;
1623 	u32 sid = cred_sid(cred);
1624 	u32 av = CAP_TO_MASK(cap);
1625 	int rc;
1626 
1627 	ad.type = LSM_AUDIT_DATA_CAP;
1628 	ad.u.cap = cap;
1629 
1630 	switch (CAP_TO_INDEX(cap)) {
1631 	case 0:
1632 		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1633 		break;
1634 	case 1:
1635 		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1636 		break;
1637 	default:
1638 		pr_err("SELinux:  out of range capability %d\n", cap);
1639 		BUG();
1640 		return -EINVAL;
1641 	}
1642 
1643 	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1644 	if (!(opts & CAP_OPT_NOAUDIT)) {
1645 		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1646 		if (rc2)
1647 			return rc2;
1648 	}
1649 	return rc;
1650 }
1651 
1652 /* Check whether a task has a particular permission to an inode.
1653    The 'adp' parameter is optional and allows other audit
1654    data to be passed (e.g. the dentry). */
inode_has_perm(const struct cred * cred,struct inode * inode,u32 perms,struct common_audit_data * adp)1655 static int inode_has_perm(const struct cred *cred,
1656 			  struct inode *inode,
1657 			  u32 perms,
1658 			  struct common_audit_data *adp)
1659 {
1660 	struct inode_security_struct *isec;
1661 	u32 sid;
1662 
1663 	validate_creds(cred);
1664 
1665 	if (unlikely(IS_PRIVATE(inode)))
1666 		return 0;
1667 
1668 	sid = cred_sid(cred);
1669 	isec = selinux_inode(inode);
1670 
1671 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1672 }
1673 
1674 /* Same as inode_has_perm, but pass explicit audit data containing
1675    the dentry to help the auditing code to more easily generate the
1676    pathname if needed. */
dentry_has_perm(const struct cred * cred,struct dentry * dentry,u32 av)1677 static inline int dentry_has_perm(const struct cred *cred,
1678 				  struct dentry *dentry,
1679 				  u32 av)
1680 {
1681 	struct inode *inode = d_backing_inode(dentry);
1682 	struct common_audit_data ad;
1683 
1684 	ad.type = LSM_AUDIT_DATA_DENTRY;
1685 	ad.u.dentry = dentry;
1686 	__inode_security_revalidate(inode, dentry, true);
1687 	return inode_has_perm(cred, inode, av, &ad);
1688 }
1689 
1690 /* Same as inode_has_perm, but pass explicit audit data containing
1691    the path to help the auditing code to more easily generate the
1692    pathname if needed. */
path_has_perm(const struct cred * cred,const struct path * path,u32 av)1693 static inline int path_has_perm(const struct cred *cred,
1694 				const struct path *path,
1695 				u32 av)
1696 {
1697 	struct inode *inode = d_backing_inode(path->dentry);
1698 	struct common_audit_data ad;
1699 
1700 	ad.type = LSM_AUDIT_DATA_PATH;
1701 	ad.u.path = *path;
1702 	__inode_security_revalidate(inode, path->dentry, true);
1703 	return inode_has_perm(cred, inode, av, &ad);
1704 }
1705 
1706 /* Same as path_has_perm, but uses the inode from the file struct. */
file_path_has_perm(const struct cred * cred,struct file * file,u32 av)1707 static inline int file_path_has_perm(const struct cred *cred,
1708 				     struct file *file,
1709 				     u32 av)
1710 {
1711 	struct common_audit_data ad;
1712 
1713 	ad.type = LSM_AUDIT_DATA_FILE;
1714 	ad.u.file = file;
1715 	return inode_has_perm(cred, file_inode(file), av, &ad);
1716 }
1717 
1718 #ifdef CONFIG_BPF_SYSCALL
1719 static int bpf_fd_pass(const struct file *file, u32 sid);
1720 #endif
1721 
1722 /* Check whether a task can use an open file descriptor to
1723    access an inode in a given way.  Check access to the
1724    descriptor itself, and then use dentry_has_perm to
1725    check a particular permission to the file.
1726    Access to the descriptor is implicitly granted if it
1727    has the same SID as the process.  If av is zero, then
1728    access to the file is not checked, e.g. for cases
1729    where only the descriptor is affected like seek. */
file_has_perm(const struct cred * cred,struct file * file,u32 av)1730 static int file_has_perm(const struct cred *cred,
1731 			 struct file *file,
1732 			 u32 av)
1733 {
1734 	struct file_security_struct *fsec = selinux_file(file);
1735 	struct inode *inode = file_inode(file);
1736 	struct common_audit_data ad;
1737 	u32 sid = cred_sid(cred);
1738 	int rc;
1739 
1740 	ad.type = LSM_AUDIT_DATA_FILE;
1741 	ad.u.file = file;
1742 
1743 	if (sid != fsec->sid) {
1744 		rc = avc_has_perm(sid, fsec->sid,
1745 				  SECCLASS_FD,
1746 				  FD__USE,
1747 				  &ad);
1748 		if (rc)
1749 			goto out;
1750 	}
1751 
1752 #ifdef CONFIG_BPF_SYSCALL
1753 	rc = bpf_fd_pass(file, cred_sid(cred));
1754 	if (rc)
1755 		return rc;
1756 #endif
1757 
1758 	/* av is zero if only checking access to the descriptor. */
1759 	rc = 0;
1760 	if (av)
1761 		rc = inode_has_perm(cred, inode, av, &ad);
1762 
1763 out:
1764 	return rc;
1765 }
1766 
1767 /*
1768  * Determine the label for an inode that might be unioned.
1769  */
1770 static int
selinux_determine_inode_label(const struct task_security_struct * tsec,struct inode * dir,const struct qstr * name,u16 tclass,u32 * _new_isid)1771 selinux_determine_inode_label(const struct task_security_struct *tsec,
1772 				 struct inode *dir,
1773 				 const struct qstr *name, u16 tclass,
1774 				 u32 *_new_isid)
1775 {
1776 	const struct superblock_security_struct *sbsec =
1777 						selinux_superblock(dir->i_sb);
1778 
1779 	if ((sbsec->flags & SE_SBINITIALIZED) &&
1780 	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
1781 		*_new_isid = sbsec->mntpoint_sid;
1782 	} else if ((sbsec->flags & SBLABEL_MNT) &&
1783 		   tsec->create_sid) {
1784 		*_new_isid = tsec->create_sid;
1785 	} else {
1786 		const struct inode_security_struct *dsec = inode_security(dir);
1787 		return security_transition_sid(tsec->sid,
1788 					       dsec->sid, tclass,
1789 					       name, _new_isid);
1790 	}
1791 
1792 	return 0;
1793 }
1794 
1795 /* Check whether a task can create a file. */
may_create(struct inode * dir,struct dentry * dentry,u16 tclass)1796 static int may_create(struct inode *dir,
1797 		      struct dentry *dentry,
1798 		      u16 tclass)
1799 {
1800 	const struct task_security_struct *tsec = selinux_cred(current_cred());
1801 	struct inode_security_struct *dsec;
1802 	struct superblock_security_struct *sbsec;
1803 	u32 sid, newsid;
1804 	struct common_audit_data ad;
1805 	int rc;
1806 
1807 	dsec = inode_security(dir);
1808 	sbsec = selinux_superblock(dir->i_sb);
1809 
1810 	sid = tsec->sid;
1811 
1812 	ad.type = LSM_AUDIT_DATA_DENTRY;
1813 	ad.u.dentry = dentry;
1814 
1815 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1816 			  DIR__ADD_NAME | DIR__SEARCH,
1817 			  &ad);
1818 	if (rc)
1819 		return rc;
1820 
1821 	rc = selinux_determine_inode_label(tsec, dir, &dentry->d_name, tclass,
1822 					   &newsid);
1823 	if (rc)
1824 		return rc;
1825 
1826 	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1827 	if (rc)
1828 		return rc;
1829 
1830 	return avc_has_perm(newsid, sbsec->sid,
1831 			    SECCLASS_FILESYSTEM,
1832 			    FILESYSTEM__ASSOCIATE, &ad);
1833 }
1834 
1835 #define MAY_LINK	0
1836 #define MAY_UNLINK	1
1837 #define MAY_RMDIR	2
1838 
1839 /* Check whether a task can link, unlink, or rmdir a file/directory. */
may_link(struct inode * dir,struct dentry * dentry,int kind)1840 static int may_link(struct inode *dir,
1841 		    struct dentry *dentry,
1842 		    int kind)
1843 
1844 {
1845 	struct inode_security_struct *dsec, *isec;
1846 	struct common_audit_data ad;
1847 	u32 sid = current_sid();
1848 	u32 av;
1849 	int rc;
1850 
1851 	dsec = inode_security(dir);
1852 	isec = backing_inode_security(dentry);
1853 
1854 	ad.type = LSM_AUDIT_DATA_DENTRY;
1855 	ad.u.dentry = dentry;
1856 
1857 	av = DIR__SEARCH;
1858 	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1859 	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1860 	if (rc)
1861 		return rc;
1862 
1863 	switch (kind) {
1864 	case MAY_LINK:
1865 		av = FILE__LINK;
1866 		break;
1867 	case MAY_UNLINK:
1868 		av = FILE__UNLINK;
1869 		break;
1870 	case MAY_RMDIR:
1871 		av = DIR__RMDIR;
1872 		break;
1873 	default:
1874 		pr_warn("SELinux: %s:  unrecognized kind %d\n",
1875 			__func__, kind);
1876 		return 0;
1877 	}
1878 
1879 	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1880 	return rc;
1881 }
1882 
may_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1883 static inline int may_rename(struct inode *old_dir,
1884 			     struct dentry *old_dentry,
1885 			     struct inode *new_dir,
1886 			     struct dentry *new_dentry)
1887 {
1888 	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1889 	struct common_audit_data ad;
1890 	u32 sid = current_sid();
1891 	u32 av;
1892 	int old_is_dir, new_is_dir;
1893 	int rc;
1894 
1895 	old_dsec = inode_security(old_dir);
1896 	old_isec = backing_inode_security(old_dentry);
1897 	old_is_dir = d_is_dir(old_dentry);
1898 	new_dsec = inode_security(new_dir);
1899 
1900 	ad.type = LSM_AUDIT_DATA_DENTRY;
1901 
1902 	ad.u.dentry = old_dentry;
1903 	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1904 			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1905 	if (rc)
1906 		return rc;
1907 	rc = avc_has_perm(sid, old_isec->sid,
1908 			  old_isec->sclass, FILE__RENAME, &ad);
1909 	if (rc)
1910 		return rc;
1911 	if (old_is_dir && new_dir != old_dir) {
1912 		rc = avc_has_perm(sid, old_isec->sid,
1913 				  old_isec->sclass, DIR__REPARENT, &ad);
1914 		if (rc)
1915 			return rc;
1916 	}
1917 
1918 	ad.u.dentry = new_dentry;
1919 	av = DIR__ADD_NAME | DIR__SEARCH;
1920 	if (d_is_positive(new_dentry))
1921 		av |= DIR__REMOVE_NAME;
1922 	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1923 	if (rc)
1924 		return rc;
1925 	if (d_is_positive(new_dentry)) {
1926 		new_isec = backing_inode_security(new_dentry);
1927 		new_is_dir = d_is_dir(new_dentry);
1928 		rc = avc_has_perm(sid, new_isec->sid,
1929 				  new_isec->sclass,
1930 				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1931 		if (rc)
1932 			return rc;
1933 	}
1934 
1935 	return 0;
1936 }
1937 
1938 /* Check whether a task can perform a filesystem operation. */
superblock_has_perm(const struct cred * cred,struct super_block * sb,u32 perms,struct common_audit_data * ad)1939 static int superblock_has_perm(const struct cred *cred,
1940 			       struct super_block *sb,
1941 			       u32 perms,
1942 			       struct common_audit_data *ad)
1943 {
1944 	struct superblock_security_struct *sbsec;
1945 	u32 sid = cred_sid(cred);
1946 
1947 	sbsec = selinux_superblock(sb);
1948 	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1949 }
1950 
1951 /* Convert a Linux mode and permission mask to an access vector. */
file_mask_to_av(int mode,int mask)1952 static inline u32 file_mask_to_av(int mode, int mask)
1953 {
1954 	u32 av = 0;
1955 
1956 	if (!S_ISDIR(mode)) {
1957 		if (mask & MAY_EXEC)
1958 			av |= FILE__EXECUTE;
1959 		if (mask & MAY_READ)
1960 			av |= FILE__READ;
1961 
1962 		if (mask & MAY_APPEND)
1963 			av |= FILE__APPEND;
1964 		else if (mask & MAY_WRITE)
1965 			av |= FILE__WRITE;
1966 
1967 	} else {
1968 		if (mask & MAY_EXEC)
1969 			av |= DIR__SEARCH;
1970 		if (mask & MAY_WRITE)
1971 			av |= DIR__WRITE;
1972 		if (mask & MAY_READ)
1973 			av |= DIR__READ;
1974 	}
1975 
1976 	return av;
1977 }
1978 
1979 /* Convert a Linux file to an access vector. */
file_to_av(const struct file * file)1980 static inline u32 file_to_av(const struct file *file)
1981 {
1982 	u32 av = 0;
1983 
1984 	if (file->f_mode & FMODE_READ)
1985 		av |= FILE__READ;
1986 	if (file->f_mode & FMODE_WRITE) {
1987 		if (file->f_flags & O_APPEND)
1988 			av |= FILE__APPEND;
1989 		else
1990 			av |= FILE__WRITE;
1991 	}
1992 	if (!av) {
1993 		/*
1994 		 * Special file opened with flags 3 for ioctl-only use.
1995 		 */
1996 		av = FILE__IOCTL;
1997 	}
1998 
1999 	return av;
2000 }
2001 
2002 /*
2003  * Convert a file to an access vector and include the correct
2004  * open permission.
2005  */
open_file_to_av(struct file * file)2006 static inline u32 open_file_to_av(struct file *file)
2007 {
2008 	u32 av = file_to_av(file);
2009 	struct inode *inode = file_inode(file);
2010 
2011 	if (selinux_policycap_openperm() &&
2012 	    inode->i_sb->s_magic != SOCKFS_MAGIC)
2013 		av |= FILE__OPEN;
2014 
2015 	return av;
2016 }
2017 
2018 /* Hook functions begin here. */
2019 
selinux_binder_set_context_mgr(const struct cred * mgr)2020 static int selinux_binder_set_context_mgr(const struct cred *mgr)
2021 {
2022 	return avc_has_perm(current_sid(), cred_sid(mgr), SECCLASS_BINDER,
2023 			    BINDER__SET_CONTEXT_MGR, NULL);
2024 }
2025 
selinux_binder_transaction(const struct cred * from,const struct cred * to)2026 static int selinux_binder_transaction(const struct cred *from,
2027 				      const struct cred *to)
2028 {
2029 	u32 mysid = current_sid();
2030 	u32 fromsid = cred_sid(from);
2031 	u32 tosid = cred_sid(to);
2032 	int rc;
2033 
2034 	if (mysid != fromsid) {
2035 		rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
2036 				  BINDER__IMPERSONATE, NULL);
2037 		if (rc)
2038 			return rc;
2039 	}
2040 
2041 	return avc_has_perm(fromsid, tosid,
2042 			    SECCLASS_BINDER, BINDER__CALL, NULL);
2043 }
2044 
selinux_binder_transfer_binder(const struct cred * from,const struct cred * to)2045 static int selinux_binder_transfer_binder(const struct cred *from,
2046 					  const struct cred *to)
2047 {
2048 	return avc_has_perm(cred_sid(from), cred_sid(to),
2049 			    SECCLASS_BINDER, BINDER__TRANSFER,
2050 			    NULL);
2051 }
2052 
selinux_binder_transfer_file(const struct cred * from,const struct cred * to,const struct file * file)2053 static int selinux_binder_transfer_file(const struct cred *from,
2054 					const struct cred *to,
2055 					const struct file *file)
2056 {
2057 	u32 sid = cred_sid(to);
2058 	struct file_security_struct *fsec = selinux_file(file);
2059 	struct dentry *dentry = file->f_path.dentry;
2060 	struct inode_security_struct *isec;
2061 	struct common_audit_data ad;
2062 	int rc;
2063 
2064 	ad.type = LSM_AUDIT_DATA_PATH;
2065 	ad.u.path = file->f_path;
2066 
2067 	if (sid != fsec->sid) {
2068 		rc = avc_has_perm(sid, fsec->sid,
2069 				  SECCLASS_FD,
2070 				  FD__USE,
2071 				  &ad);
2072 		if (rc)
2073 			return rc;
2074 	}
2075 
2076 #ifdef CONFIG_BPF_SYSCALL
2077 	rc = bpf_fd_pass(file, sid);
2078 	if (rc)
2079 		return rc;
2080 #endif
2081 
2082 	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2083 		return 0;
2084 
2085 	isec = backing_inode_security(dentry);
2086 	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
2087 			    &ad);
2088 }
2089 
selinux_ptrace_access_check(struct task_struct * child,unsigned int mode)2090 static int selinux_ptrace_access_check(struct task_struct *child,
2091 				       unsigned int mode)
2092 {
2093 	u32 sid = current_sid();
2094 	u32 csid = task_sid_obj(child);
2095 
2096 	if (mode & PTRACE_MODE_READ)
2097 		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ,
2098 				NULL);
2099 
2100 	return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE,
2101 			NULL);
2102 }
2103 
selinux_ptrace_traceme(struct task_struct * parent)2104 static int selinux_ptrace_traceme(struct task_struct *parent)
2105 {
2106 	return avc_has_perm(task_sid_obj(parent), task_sid_obj(current),
2107 			    SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2108 }
2109 
selinux_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)2110 static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
2111 			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
2112 {
2113 	return avc_has_perm(current_sid(), task_sid_obj(target),
2114 			SECCLASS_PROCESS, PROCESS__GETCAP, NULL);
2115 }
2116 
selinux_capset(struct cred * new,const struct cred * old,const kernel_cap_t * effective,const kernel_cap_t * inheritable,const kernel_cap_t * permitted)2117 static int selinux_capset(struct cred *new, const struct cred *old,
2118 			  const kernel_cap_t *effective,
2119 			  const kernel_cap_t *inheritable,
2120 			  const kernel_cap_t *permitted)
2121 {
2122 	return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
2123 			    PROCESS__SETCAP, NULL);
2124 }
2125 
2126 /*
2127  * (This comment used to live with the selinux_task_setuid hook,
2128  * which was removed).
2129  *
2130  * Since setuid only affects the current process, and since the SELinux
2131  * controls are not based on the Linux identity attributes, SELinux does not
2132  * need to control this operation.  However, SELinux does control the use of
2133  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
2134  */
2135 
selinux_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)2136 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
2137 			   int cap, unsigned int opts)
2138 {
2139 	return cred_has_capability(cred, cap, opts, ns == &init_user_ns);
2140 }
2141 
selinux_quotactl(int cmds,int type,int id,struct super_block * sb)2142 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
2143 {
2144 	const struct cred *cred = current_cred();
2145 	int rc = 0;
2146 
2147 	if (!sb)
2148 		return 0;
2149 
2150 	switch (cmds) {
2151 	case Q_SYNC:
2152 	case Q_QUOTAON:
2153 	case Q_QUOTAOFF:
2154 	case Q_SETINFO:
2155 	case Q_SETQUOTA:
2156 	case Q_XQUOTAOFF:
2157 	case Q_XQUOTAON:
2158 	case Q_XSETQLIM:
2159 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2160 		break;
2161 	case Q_GETFMT:
2162 	case Q_GETINFO:
2163 	case Q_GETQUOTA:
2164 	case Q_XGETQUOTA:
2165 	case Q_XGETQSTAT:
2166 	case Q_XGETQSTATV:
2167 	case Q_XGETNEXTQUOTA:
2168 		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2169 		break;
2170 	default:
2171 		rc = 0;  /* let the kernel handle invalid cmds */
2172 		break;
2173 	}
2174 	return rc;
2175 }
2176 
selinux_quota_on(struct dentry * dentry)2177 static int selinux_quota_on(struct dentry *dentry)
2178 {
2179 	const struct cred *cred = current_cred();
2180 
2181 	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
2182 }
2183 
selinux_syslog(int type)2184 static int selinux_syslog(int type)
2185 {
2186 	switch (type) {
2187 	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
2188 	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2189 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2190 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2191 	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
2192 	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
2193 	/* Set level of messages printed to console */
2194 	case SYSLOG_ACTION_CONSOLE_LEVEL:
2195 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2196 				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
2197 				    NULL);
2198 	}
2199 	/* All other syslog types */
2200 	return avc_has_perm(current_sid(), SECINITSID_KERNEL,
2201 			    SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
2202 }
2203 
2204 /*
2205  * Check that a process has enough memory to allocate a new virtual
2206  * mapping. 0 means there is enough memory for the allocation to
2207  * succeed and -ENOMEM implies there is not.
2208  *
2209  * Do not audit the selinux permission check, as this is applied to all
2210  * processes that allocate mappings.
2211  */
selinux_vm_enough_memory(struct mm_struct * mm,long pages)2212 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2213 {
2214 	int rc, cap_sys_admin = 0;
2215 
2216 	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2217 				 CAP_OPT_NOAUDIT, true);
2218 	if (rc == 0)
2219 		cap_sys_admin = 1;
2220 
2221 	return cap_sys_admin;
2222 }
2223 
2224 /* binprm security operations */
2225 
ptrace_parent_sid(void)2226 static u32 ptrace_parent_sid(void)
2227 {
2228 	u32 sid = 0;
2229 	struct task_struct *tracer;
2230 
2231 	rcu_read_lock();
2232 	tracer = ptrace_parent(current);
2233 	if (tracer)
2234 		sid = task_sid_obj(tracer);
2235 	rcu_read_unlock();
2236 
2237 	return sid;
2238 }
2239 
check_nnp_nosuid(const struct linux_binprm * bprm,const struct task_security_struct * old_tsec,const struct task_security_struct * new_tsec)2240 static int check_nnp_nosuid(const struct linux_binprm *bprm,
2241 			    const struct task_security_struct *old_tsec,
2242 			    const struct task_security_struct *new_tsec)
2243 {
2244 	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2245 	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2246 	int rc;
2247 	u32 av;
2248 
2249 	if (!nnp && !nosuid)
2250 		return 0; /* neither NNP nor nosuid */
2251 
2252 	if (new_tsec->sid == old_tsec->sid)
2253 		return 0; /* No change in credentials */
2254 
2255 	/*
2256 	 * If the policy enables the nnp_nosuid_transition policy capability,
2257 	 * then we permit transitions under NNP or nosuid if the
2258 	 * policy allows the corresponding permission between
2259 	 * the old and new contexts.
2260 	 */
2261 	if (selinux_policycap_nnp_nosuid_transition()) {
2262 		av = 0;
2263 		if (nnp)
2264 			av |= PROCESS2__NNP_TRANSITION;
2265 		if (nosuid)
2266 			av |= PROCESS2__NOSUID_TRANSITION;
2267 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2268 				  SECCLASS_PROCESS2, av, NULL);
2269 		if (!rc)
2270 			return 0;
2271 	}
2272 
2273 	/*
2274 	 * We also permit NNP or nosuid transitions to bounded SIDs,
2275 	 * i.e. SIDs that are guaranteed to only be allowed a subset
2276 	 * of the permissions of the current SID.
2277 	 */
2278 	rc = security_bounded_transition(old_tsec->sid,
2279 					 new_tsec->sid);
2280 	if (!rc)
2281 		return 0;
2282 
2283 	/*
2284 	 * On failure, preserve the errno values for NNP vs nosuid.
2285 	 * NNP:  Operation not permitted for caller.
2286 	 * nosuid:  Permission denied to file.
2287 	 */
2288 	if (nnp)
2289 		return -EPERM;
2290 	return -EACCES;
2291 }
2292 
selinux_bprm_creds_for_exec(struct linux_binprm * bprm)2293 static int selinux_bprm_creds_for_exec(struct linux_binprm *bprm)
2294 {
2295 	const struct task_security_struct *old_tsec;
2296 	struct task_security_struct *new_tsec;
2297 	struct inode_security_struct *isec;
2298 	struct common_audit_data ad;
2299 	struct inode *inode = file_inode(bprm->file);
2300 	int rc;
2301 
2302 	/* SELinux context only depends on initial program or script and not
2303 	 * the script interpreter */
2304 
2305 	old_tsec = selinux_cred(current_cred());
2306 	new_tsec = selinux_cred(bprm->cred);
2307 	isec = inode_security(inode);
2308 
2309 	/* Default to the current task SID. */
2310 	new_tsec->sid = old_tsec->sid;
2311 	new_tsec->osid = old_tsec->sid;
2312 
2313 	/* Reset fs, key, and sock SIDs on execve. */
2314 	new_tsec->create_sid = 0;
2315 	new_tsec->keycreate_sid = 0;
2316 	new_tsec->sockcreate_sid = 0;
2317 
2318 	if (old_tsec->exec_sid) {
2319 		new_tsec->sid = old_tsec->exec_sid;
2320 		/* Reset exec SID on execve. */
2321 		new_tsec->exec_sid = 0;
2322 
2323 		/* Fail on NNP or nosuid if not an allowed transition. */
2324 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2325 		if (rc)
2326 			return rc;
2327 	} else {
2328 		/* Check for a default transition on this program. */
2329 		rc = security_transition_sid(old_tsec->sid,
2330 					     isec->sid, SECCLASS_PROCESS, NULL,
2331 					     &new_tsec->sid);
2332 		if (rc)
2333 			return rc;
2334 
2335 		/*
2336 		 * Fallback to old SID on NNP or nosuid if not an allowed
2337 		 * transition.
2338 		 */
2339 		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
2340 		if (rc)
2341 			new_tsec->sid = old_tsec->sid;
2342 	}
2343 
2344 	ad.type = LSM_AUDIT_DATA_FILE;
2345 	ad.u.file = bprm->file;
2346 
2347 	if (new_tsec->sid == old_tsec->sid) {
2348 		rc = avc_has_perm(old_tsec->sid, isec->sid,
2349 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2350 		if (rc)
2351 			return rc;
2352 	} else {
2353 		/* Check permissions for the transition. */
2354 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2355 				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2356 		if (rc)
2357 			return rc;
2358 
2359 		rc = avc_has_perm(new_tsec->sid, isec->sid,
2360 				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2361 		if (rc)
2362 			return rc;
2363 
2364 		/* Check for shared state */
2365 		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2366 			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2367 					  SECCLASS_PROCESS, PROCESS__SHARE,
2368 					  NULL);
2369 			if (rc)
2370 				return -EPERM;
2371 		}
2372 
2373 		/* Make sure that anyone attempting to ptrace over a task that
2374 		 * changes its SID has the appropriate permit */
2375 		if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2376 			u32 ptsid = ptrace_parent_sid();
2377 			if (ptsid != 0) {
2378 				rc = avc_has_perm(ptsid, new_tsec->sid,
2379 						  SECCLASS_PROCESS,
2380 						  PROCESS__PTRACE, NULL);
2381 				if (rc)
2382 					return -EPERM;
2383 			}
2384 		}
2385 
2386 		/* Clear any possibly unsafe personality bits on exec: */
2387 		bprm->per_clear |= PER_CLEAR_ON_SETID;
2388 
2389 		/* Enable secure mode for SIDs transitions unless
2390 		   the noatsecure permission is granted between
2391 		   the two SIDs, i.e. ahp returns 0. */
2392 		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2393 				  SECCLASS_PROCESS, PROCESS__NOATSECURE,
2394 				  NULL);
2395 		bprm->secureexec |= !!rc;
2396 	}
2397 
2398 	return 0;
2399 }
2400 
match_file(const void * p,struct file * file,unsigned fd)2401 static int match_file(const void *p, struct file *file, unsigned fd)
2402 {
2403 	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
2404 }
2405 
2406 /* Derived from fs/exec.c:flush_old_files. */
flush_unauthorized_files(const struct cred * cred,struct files_struct * files)2407 static inline void flush_unauthorized_files(const struct cred *cred,
2408 					    struct files_struct *files)
2409 {
2410 	struct file *file, *devnull = NULL;
2411 	struct tty_struct *tty;
2412 	int drop_tty = 0;
2413 	unsigned n;
2414 
2415 	tty = get_current_tty();
2416 	if (tty) {
2417 		spin_lock(&tty->files_lock);
2418 		if (!list_empty(&tty->tty_files)) {
2419 			struct tty_file_private *file_priv;
2420 
2421 			/* Revalidate access to controlling tty.
2422 			   Use file_path_has_perm on the tty path directly
2423 			   rather than using file_has_perm, as this particular
2424 			   open file may belong to another process and we are
2425 			   only interested in the inode-based check here. */
2426 			file_priv = list_first_entry(&tty->tty_files,
2427 						struct tty_file_private, list);
2428 			file = file_priv->file;
2429 			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2430 				drop_tty = 1;
2431 		}
2432 		spin_unlock(&tty->files_lock);
2433 		tty_kref_put(tty);
2434 	}
2435 	/* Reset controlling tty. */
2436 	if (drop_tty)
2437 		no_tty();
2438 
2439 	/* Revalidate access to inherited open files. */
2440 	n = iterate_fd(files, 0, match_file, cred);
2441 	if (!n) /* none found? */
2442 		return;
2443 
2444 	devnull = dentry_open(&selinux_null, O_RDWR, cred);
2445 	if (IS_ERR(devnull))
2446 		devnull = NULL;
2447 	/* replace all the matching ones with this */
2448 	do {
2449 		replace_fd(n - 1, devnull, 0);
2450 	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
2451 	if (devnull)
2452 		fput(devnull);
2453 }
2454 
2455 /*
2456  * Prepare a process for imminent new credential changes due to exec
2457  */
selinux_bprm_committing_creds(struct linux_binprm * bprm)2458 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2459 {
2460 	struct task_security_struct *new_tsec;
2461 	struct rlimit *rlim, *initrlim;
2462 	int rc, i;
2463 
2464 	new_tsec = selinux_cred(bprm->cred);
2465 	if (new_tsec->sid == new_tsec->osid)
2466 		return;
2467 
2468 	/* Close files for which the new task SID is not authorized. */
2469 	flush_unauthorized_files(bprm->cred, current->files);
2470 
2471 	/* Always clear parent death signal on SID transitions. */
2472 	current->pdeath_signal = 0;
2473 
2474 	/* Check whether the new SID can inherit resource limits from the old
2475 	 * SID.  If not, reset all soft limits to the lower of the current
2476 	 * task's hard limit and the init task's soft limit.
2477 	 *
2478 	 * Note that the setting of hard limits (even to lower them) can be
2479 	 * controlled by the setrlimit check.  The inclusion of the init task's
2480 	 * soft limit into the computation is to avoid resetting soft limits
2481 	 * higher than the default soft limit for cases where the default is
2482 	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2483 	 */
2484 	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2485 			  PROCESS__RLIMITINH, NULL);
2486 	if (rc) {
2487 		/* protect against do_prlimit() */
2488 		task_lock(current);
2489 		for (i = 0; i < RLIM_NLIMITS; i++) {
2490 			rlim = current->signal->rlim + i;
2491 			initrlim = init_task.signal->rlim + i;
2492 			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2493 		}
2494 		task_unlock(current);
2495 		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
2496 			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2497 	}
2498 }
2499 
2500 /*
2501  * Clean up the process immediately after the installation of new credentials
2502  * due to exec
2503  */
selinux_bprm_committed_creds(struct linux_binprm * bprm)2504 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2505 {
2506 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2507 	u32 osid, sid;
2508 	int rc;
2509 
2510 	osid = tsec->osid;
2511 	sid = tsec->sid;
2512 
2513 	if (sid == osid)
2514 		return;
2515 
2516 	/* Check whether the new SID can inherit signal state from the old SID.
2517 	 * If not, clear itimers to avoid subsequent signal generation and
2518 	 * flush and unblock signals.
2519 	 *
2520 	 * This must occur _after_ the task SID has been updated so that any
2521 	 * kill done after the flush will be checked against the new SID.
2522 	 */
2523 	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2524 	if (rc) {
2525 		clear_itimer();
2526 
2527 		spin_lock_irq(&unrcu_pointer(current->sighand)->siglock);
2528 		if (!fatal_signal_pending(current)) {
2529 			flush_sigqueue(&current->pending);
2530 			flush_sigqueue(&current->signal->shared_pending);
2531 			flush_signal_handlers(current, 1);
2532 			sigemptyset(&current->blocked);
2533 			recalc_sigpending();
2534 		}
2535 		spin_unlock_irq(&unrcu_pointer(current->sighand)->siglock);
2536 	}
2537 
2538 	/* Wake up the parent if it is waiting so that it can recheck
2539 	 * wait permission to the new task SID. */
2540 	read_lock(&tasklist_lock);
2541 	__wake_up_parent(current, unrcu_pointer(current->real_parent));
2542 	read_unlock(&tasklist_lock);
2543 }
2544 
2545 /* superblock security operations */
2546 
selinux_sb_alloc_security(struct super_block * sb)2547 static int selinux_sb_alloc_security(struct super_block *sb)
2548 {
2549 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2550 
2551 	mutex_init(&sbsec->lock);
2552 	INIT_LIST_HEAD(&sbsec->isec_head);
2553 	spin_lock_init(&sbsec->isec_lock);
2554 	sbsec->sid = SECINITSID_UNLABELED;
2555 	sbsec->def_sid = SECINITSID_FILE;
2556 	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
2557 
2558 	return 0;
2559 }
2560 
opt_len(const char * s)2561 static inline int opt_len(const char *s)
2562 {
2563 	bool open_quote = false;
2564 	int len;
2565 	char c;
2566 
2567 	for (len = 0; (c = s[len]) != '\0'; len++) {
2568 		if (c == '"')
2569 			open_quote = !open_quote;
2570 		if (c == ',' && !open_quote)
2571 			break;
2572 	}
2573 	return len;
2574 }
2575 
selinux_sb_eat_lsm_opts(char * options,void ** mnt_opts)2576 static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
2577 {
2578 	char *from = options;
2579 	char *to = options;
2580 	bool first = true;
2581 	int rc;
2582 
2583 	while (1) {
2584 		int len = opt_len(from);
2585 		int token;
2586 		char *arg = NULL;
2587 
2588 		token = match_opt_prefix(from, len, &arg);
2589 
2590 		if (token != Opt_error) {
2591 			char *p, *q;
2592 
2593 			/* strip quotes */
2594 			if (arg) {
2595 				for (p = q = arg; p < from + len; p++) {
2596 					char c = *p;
2597 					if (c != '"')
2598 						*q++ = c;
2599 				}
2600 				arg = kmemdup_nul(arg, q - arg, GFP_KERNEL);
2601 				if (!arg) {
2602 					rc = -ENOMEM;
2603 					goto free_opt;
2604 				}
2605 			}
2606 			rc = selinux_add_opt(token, arg, mnt_opts);
2607 			kfree(arg);
2608 			arg = NULL;
2609 			if (unlikely(rc)) {
2610 				goto free_opt;
2611 			}
2612 		} else {
2613 			if (!first) {	// copy with preceding comma
2614 				from--;
2615 				len++;
2616 			}
2617 			if (to != from)
2618 				memmove(to, from, len);
2619 			to += len;
2620 			first = false;
2621 		}
2622 		if (!from[len])
2623 			break;
2624 		from += len + 1;
2625 	}
2626 	*to = '\0';
2627 	return 0;
2628 
2629 free_opt:
2630 	if (*mnt_opts) {
2631 		selinux_free_mnt_opts(*mnt_opts);
2632 		*mnt_opts = NULL;
2633 	}
2634 	return rc;
2635 }
2636 
selinux_sb_mnt_opts_compat(struct super_block * sb,void * mnt_opts)2637 static int selinux_sb_mnt_opts_compat(struct super_block *sb, void *mnt_opts)
2638 {
2639 	struct selinux_mnt_opts *opts = mnt_opts;
2640 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2641 
2642 	/*
2643 	 * Superblock not initialized (i.e. no options) - reject if any
2644 	 * options specified, otherwise accept.
2645 	 */
2646 	if (!(sbsec->flags & SE_SBINITIALIZED))
2647 		return opts ? 1 : 0;
2648 
2649 	/*
2650 	 * Superblock initialized and no options specified - reject if
2651 	 * superblock has any options set, otherwise accept.
2652 	 */
2653 	if (!opts)
2654 		return (sbsec->flags & SE_MNTMASK) ? 1 : 0;
2655 
2656 	if (opts->fscontext_sid) {
2657 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2658 			       opts->fscontext_sid))
2659 			return 1;
2660 	}
2661 	if (opts->context_sid) {
2662 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2663 			       opts->context_sid))
2664 			return 1;
2665 	}
2666 	if (opts->rootcontext_sid) {
2667 		struct inode_security_struct *root_isec;
2668 
2669 		root_isec = backing_inode_security(sb->s_root);
2670 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2671 			       opts->rootcontext_sid))
2672 			return 1;
2673 	}
2674 	if (opts->defcontext_sid) {
2675 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2676 			       opts->defcontext_sid))
2677 			return 1;
2678 	}
2679 	return 0;
2680 }
2681 
selinux_sb_remount(struct super_block * sb,void * mnt_opts)2682 static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
2683 {
2684 	struct selinux_mnt_opts *opts = mnt_opts;
2685 	struct superblock_security_struct *sbsec = selinux_superblock(sb);
2686 
2687 	if (!(sbsec->flags & SE_SBINITIALIZED))
2688 		return 0;
2689 
2690 	if (!opts)
2691 		return 0;
2692 
2693 	if (opts->fscontext_sid) {
2694 		if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
2695 			       opts->fscontext_sid))
2696 			goto out_bad_option;
2697 	}
2698 	if (opts->context_sid) {
2699 		if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
2700 			       opts->context_sid))
2701 			goto out_bad_option;
2702 	}
2703 	if (opts->rootcontext_sid) {
2704 		struct inode_security_struct *root_isec;
2705 		root_isec = backing_inode_security(sb->s_root);
2706 		if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
2707 			       opts->rootcontext_sid))
2708 			goto out_bad_option;
2709 	}
2710 	if (opts->defcontext_sid) {
2711 		if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
2712 			       opts->defcontext_sid))
2713 			goto out_bad_option;
2714 	}
2715 	return 0;
2716 
2717 out_bad_option:
2718 	pr_warn("SELinux: unable to change security options "
2719 	       "during remount (dev %s, type=%s)\n", sb->s_id,
2720 	       sb->s_type->name);
2721 	return -EINVAL;
2722 }
2723 
selinux_sb_kern_mount(struct super_block * sb)2724 static int selinux_sb_kern_mount(struct super_block *sb)
2725 {
2726 	const struct cred *cred = current_cred();
2727 	struct common_audit_data ad;
2728 
2729 	ad.type = LSM_AUDIT_DATA_DENTRY;
2730 	ad.u.dentry = sb->s_root;
2731 	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2732 }
2733 
selinux_sb_statfs(struct dentry * dentry)2734 static int selinux_sb_statfs(struct dentry *dentry)
2735 {
2736 	const struct cred *cred = current_cred();
2737 	struct common_audit_data ad;
2738 
2739 	ad.type = LSM_AUDIT_DATA_DENTRY;
2740 	ad.u.dentry = dentry->d_sb->s_root;
2741 	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2742 }
2743 
selinux_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)2744 static int selinux_mount(const char *dev_name,
2745 			 const struct path *path,
2746 			 const char *type,
2747 			 unsigned long flags,
2748 			 void *data)
2749 {
2750 	const struct cred *cred = current_cred();
2751 
2752 	if (flags & MS_REMOUNT)
2753 		return superblock_has_perm(cred, path->dentry->d_sb,
2754 					   FILESYSTEM__REMOUNT, NULL);
2755 	else
2756 		return path_has_perm(cred, path, FILE__MOUNTON);
2757 }
2758 
selinux_move_mount(const struct path * from_path,const struct path * to_path)2759 static int selinux_move_mount(const struct path *from_path,
2760 			      const struct path *to_path)
2761 {
2762 	const struct cred *cred = current_cred();
2763 
2764 	return path_has_perm(cred, to_path, FILE__MOUNTON);
2765 }
2766 
selinux_umount(struct vfsmount * mnt,int flags)2767 static int selinux_umount(struct vfsmount *mnt, int flags)
2768 {
2769 	const struct cred *cred = current_cred();
2770 
2771 	return superblock_has_perm(cred, mnt->mnt_sb,
2772 				   FILESYSTEM__UNMOUNT, NULL);
2773 }
2774 
selinux_fs_context_submount(struct fs_context * fc,struct super_block * reference)2775 static int selinux_fs_context_submount(struct fs_context *fc,
2776 				   struct super_block *reference)
2777 {
2778 	const struct superblock_security_struct *sbsec = selinux_superblock(reference);
2779 	struct selinux_mnt_opts *opts;
2780 
2781 	/*
2782 	 * Ensure that fc->security remains NULL when no options are set
2783 	 * as expected by selinux_set_mnt_opts().
2784 	 */
2785 	if (!(sbsec->flags & (FSCONTEXT_MNT|CONTEXT_MNT|DEFCONTEXT_MNT)))
2786 		return 0;
2787 
2788 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
2789 	if (!opts)
2790 		return -ENOMEM;
2791 
2792 	if (sbsec->flags & FSCONTEXT_MNT)
2793 		opts->fscontext_sid = sbsec->sid;
2794 	if (sbsec->flags & CONTEXT_MNT)
2795 		opts->context_sid = sbsec->mntpoint_sid;
2796 	if (sbsec->flags & DEFCONTEXT_MNT)
2797 		opts->defcontext_sid = sbsec->def_sid;
2798 	fc->security = opts;
2799 	return 0;
2800 }
2801 
selinux_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)2802 static int selinux_fs_context_dup(struct fs_context *fc,
2803 				  struct fs_context *src_fc)
2804 {
2805 	const struct selinux_mnt_opts *src = src_fc->security;
2806 
2807 	if (!src)
2808 		return 0;
2809 
2810 	fc->security = kmemdup(src, sizeof(*src), GFP_KERNEL);
2811 	return fc->security ? 0 : -ENOMEM;
2812 }
2813 
2814 static const struct fs_parameter_spec selinux_fs_parameters[] = {
2815 	fsparam_string(CONTEXT_STR,	Opt_context),
2816 	fsparam_string(DEFCONTEXT_STR,	Opt_defcontext),
2817 	fsparam_string(FSCONTEXT_STR,	Opt_fscontext),
2818 	fsparam_string(ROOTCONTEXT_STR,	Opt_rootcontext),
2819 	fsparam_flag  (SECLABEL_STR,	Opt_seclabel),
2820 	{}
2821 };
2822 
selinux_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)2823 static int selinux_fs_context_parse_param(struct fs_context *fc,
2824 					  struct fs_parameter *param)
2825 {
2826 	struct fs_parse_result result;
2827 	int opt;
2828 
2829 	opt = fs_parse(fc, selinux_fs_parameters, param, &result);
2830 	if (opt < 0)
2831 		return opt;
2832 
2833 	return selinux_add_opt(opt, param->string, &fc->security);
2834 }
2835 
2836 /* inode security operations */
2837 
selinux_inode_alloc_security(struct inode * inode)2838 static int selinux_inode_alloc_security(struct inode *inode)
2839 {
2840 	struct inode_security_struct *isec = selinux_inode(inode);
2841 	u32 sid = current_sid();
2842 
2843 	spin_lock_init(&isec->lock);
2844 	INIT_LIST_HEAD(&isec->list);
2845 	isec->inode = inode;
2846 	isec->sid = SECINITSID_UNLABELED;
2847 	isec->sclass = SECCLASS_FILE;
2848 	isec->task_sid = sid;
2849 	isec->initialized = LABEL_INVALID;
2850 
2851 	return 0;
2852 }
2853 
selinux_inode_free_security(struct inode * inode)2854 static void selinux_inode_free_security(struct inode *inode)
2855 {
2856 	inode_free_security(inode);
2857 }
2858 
selinux_dentry_init_security(struct dentry * dentry,int mode,const struct qstr * name,const char ** xattr_name,void ** ctx,u32 * ctxlen)2859 static int selinux_dentry_init_security(struct dentry *dentry, int mode,
2860 					const struct qstr *name,
2861 					const char **xattr_name, void **ctx,
2862 					u32 *ctxlen)
2863 {
2864 	u32 newsid;
2865 	int rc;
2866 
2867 	rc = selinux_determine_inode_label(selinux_cred(current_cred()),
2868 					   d_inode(dentry->d_parent), name,
2869 					   inode_mode_to_security_class(mode),
2870 					   &newsid);
2871 	if (rc)
2872 		return rc;
2873 
2874 	if (xattr_name)
2875 		*xattr_name = XATTR_NAME_SELINUX;
2876 
2877 	return security_sid_to_context(newsid, (char **)ctx,
2878 				       ctxlen);
2879 }
2880 
selinux_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)2881 static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
2882 					  struct qstr *name,
2883 					  const struct cred *old,
2884 					  struct cred *new)
2885 {
2886 	u32 newsid;
2887 	int rc;
2888 	struct task_security_struct *tsec;
2889 
2890 	rc = selinux_determine_inode_label(selinux_cred(old),
2891 					   d_inode(dentry->d_parent), name,
2892 					   inode_mode_to_security_class(mode),
2893 					   &newsid);
2894 	if (rc)
2895 		return rc;
2896 
2897 	tsec = selinux_cred(new);
2898 	tsec->create_sid = newsid;
2899 	return 0;
2900 }
2901 
selinux_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,struct xattr * xattrs,int * xattr_count)2902 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2903 				       const struct qstr *qstr,
2904 				       struct xattr *xattrs, int *xattr_count)
2905 {
2906 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2907 	struct superblock_security_struct *sbsec;
2908 	struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
2909 	u32 newsid, clen;
2910 	int rc;
2911 	char *context;
2912 
2913 	sbsec = selinux_superblock(dir->i_sb);
2914 
2915 	newsid = tsec->create_sid;
2916 
2917 	rc = selinux_determine_inode_label(tsec, dir, qstr,
2918 		inode_mode_to_security_class(inode->i_mode),
2919 		&newsid);
2920 	if (rc)
2921 		return rc;
2922 
2923 	/* Possibly defer initialization to selinux_complete_init. */
2924 	if (sbsec->flags & SE_SBINITIALIZED) {
2925 		struct inode_security_struct *isec = selinux_inode(inode);
2926 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
2927 		isec->sid = newsid;
2928 		isec->initialized = LABEL_INITIALIZED;
2929 	}
2930 
2931 	if (!selinux_initialized() ||
2932 	    !(sbsec->flags & SBLABEL_MNT))
2933 		return -EOPNOTSUPP;
2934 
2935 	if (xattr) {
2936 		rc = security_sid_to_context_force(newsid,
2937 						   &context, &clen);
2938 		if (rc)
2939 			return rc;
2940 		xattr->value = context;
2941 		xattr->value_len = clen;
2942 		xattr->name = XATTR_SELINUX_SUFFIX;
2943 	}
2944 
2945 	return 0;
2946 }
2947 
selinux_inode_init_security_anon(struct inode * inode,const struct qstr * name,const struct inode * context_inode)2948 static int selinux_inode_init_security_anon(struct inode *inode,
2949 					    const struct qstr *name,
2950 					    const struct inode *context_inode)
2951 {
2952 	const struct task_security_struct *tsec = selinux_cred(current_cred());
2953 	struct common_audit_data ad;
2954 	struct inode_security_struct *isec;
2955 	int rc;
2956 
2957 	if (unlikely(!selinux_initialized()))
2958 		return 0;
2959 
2960 	isec = selinux_inode(inode);
2961 
2962 	/*
2963 	 * We only get here once per ephemeral inode.  The inode has
2964 	 * been initialized via inode_alloc_security but is otherwise
2965 	 * untouched.
2966 	 */
2967 
2968 	if (context_inode) {
2969 		struct inode_security_struct *context_isec =
2970 			selinux_inode(context_inode);
2971 		if (context_isec->initialized != LABEL_INITIALIZED) {
2972 			pr_err("SELinux:  context_inode is not initialized\n");
2973 			return -EACCES;
2974 		}
2975 
2976 		isec->sclass = context_isec->sclass;
2977 		isec->sid = context_isec->sid;
2978 	} else {
2979 		isec->sclass = SECCLASS_ANON_INODE;
2980 		rc = security_transition_sid(
2981 			tsec->sid, tsec->sid,
2982 			isec->sclass, name, &isec->sid);
2983 		if (rc)
2984 			return rc;
2985 	}
2986 
2987 	isec->initialized = LABEL_INITIALIZED;
2988 	/*
2989 	 * Now that we've initialized security, check whether we're
2990 	 * allowed to actually create this type of anonymous inode.
2991 	 */
2992 
2993 	ad.type = LSM_AUDIT_DATA_ANONINODE;
2994 	ad.u.anonclass = name ? (const char *)name->name : "?";
2995 
2996 	return avc_has_perm(tsec->sid,
2997 			    isec->sid,
2998 			    isec->sclass,
2999 			    FILE__CREATE,
3000 			    &ad);
3001 }
3002 
selinux_inode_create(struct inode * dir,struct dentry * dentry,umode_t mode)3003 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
3004 {
3005 	return may_create(dir, dentry, SECCLASS_FILE);
3006 }
3007 
selinux_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)3008 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
3009 {
3010 	return may_link(dir, old_dentry, MAY_LINK);
3011 }
3012 
selinux_inode_unlink(struct inode * dir,struct dentry * dentry)3013 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
3014 {
3015 	return may_link(dir, dentry, MAY_UNLINK);
3016 }
3017 
selinux_inode_symlink(struct inode * dir,struct dentry * dentry,const char * name)3018 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
3019 {
3020 	return may_create(dir, dentry, SECCLASS_LNK_FILE);
3021 }
3022 
selinux_inode_mkdir(struct inode * dir,struct dentry * dentry,umode_t mask)3023 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
3024 {
3025 	return may_create(dir, dentry, SECCLASS_DIR);
3026 }
3027 
selinux_inode_rmdir(struct inode * dir,struct dentry * dentry)3028 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
3029 {
3030 	return may_link(dir, dentry, MAY_RMDIR);
3031 }
3032 
selinux_inode_mknod(struct inode * dir,struct dentry * dentry,umode_t mode,dev_t dev)3033 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
3034 {
3035 	return may_create(dir, dentry, inode_mode_to_security_class(mode));
3036 }
3037 
selinux_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)3038 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3039 				struct inode *new_inode, struct dentry *new_dentry)
3040 {
3041 	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
3042 }
3043 
selinux_inode_readlink(struct dentry * dentry)3044 static int selinux_inode_readlink(struct dentry *dentry)
3045 {
3046 	const struct cred *cred = current_cred();
3047 
3048 	return dentry_has_perm(cred, dentry, FILE__READ);
3049 }
3050 
selinux_inode_follow_link(struct dentry * dentry,struct inode * inode,bool rcu)3051 static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
3052 				     bool rcu)
3053 {
3054 	const struct cred *cred = current_cred();
3055 	struct common_audit_data ad;
3056 	struct inode_security_struct *isec;
3057 	u32 sid;
3058 
3059 	validate_creds(cred);
3060 
3061 	ad.type = LSM_AUDIT_DATA_DENTRY;
3062 	ad.u.dentry = dentry;
3063 	sid = cred_sid(cred);
3064 	isec = inode_security_rcu(inode, rcu);
3065 	if (IS_ERR(isec))
3066 		return PTR_ERR(isec);
3067 
3068 	return avc_has_perm(sid, isec->sid, isec->sclass, FILE__READ, &ad);
3069 }
3070 
audit_inode_permission(struct inode * inode,u32 perms,u32 audited,u32 denied,int result)3071 static noinline int audit_inode_permission(struct inode *inode,
3072 					   u32 perms, u32 audited, u32 denied,
3073 					   int result)
3074 {
3075 	struct common_audit_data ad;
3076 	struct inode_security_struct *isec = selinux_inode(inode);
3077 
3078 	ad.type = LSM_AUDIT_DATA_INODE;
3079 	ad.u.inode = inode;
3080 
3081 	return slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3082 			    audited, denied, result, &ad);
3083 }
3084 
selinux_inode_permission(struct inode * inode,int mask)3085 static int selinux_inode_permission(struct inode *inode, int mask)
3086 {
3087 	const struct cred *cred = current_cred();
3088 	u32 perms;
3089 	bool from_access;
3090 	bool no_block = mask & MAY_NOT_BLOCK;
3091 	struct inode_security_struct *isec;
3092 	u32 sid;
3093 	struct av_decision avd;
3094 	int rc, rc2;
3095 	u32 audited, denied;
3096 
3097 	from_access = mask & MAY_ACCESS;
3098 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
3099 
3100 	/* No permission to check.  Existence test. */
3101 	if (!mask)
3102 		return 0;
3103 
3104 	validate_creds(cred);
3105 
3106 	if (unlikely(IS_PRIVATE(inode)))
3107 		return 0;
3108 
3109 	perms = file_mask_to_av(inode->i_mode, mask);
3110 
3111 	sid = cred_sid(cred);
3112 	isec = inode_security_rcu(inode, no_block);
3113 	if (IS_ERR(isec))
3114 		return PTR_ERR(isec);
3115 
3116 	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0,
3117 				  &avd);
3118 	audited = avc_audit_required(perms, &avd, rc,
3119 				     from_access ? FILE__AUDIT_ACCESS : 0,
3120 				     &denied);
3121 	if (likely(!audited))
3122 		return rc;
3123 
3124 	rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
3125 	if (rc2)
3126 		return rc2;
3127 	return rc;
3128 }
3129 
selinux_inode_setattr(struct dentry * dentry,struct iattr * iattr)3130 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
3131 {
3132 	const struct cred *cred = current_cred();
3133 	struct inode *inode = d_backing_inode(dentry);
3134 	unsigned int ia_valid = iattr->ia_valid;
3135 	__u32 av = FILE__WRITE;
3136 
3137 	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
3138 	if (ia_valid & ATTR_FORCE) {
3139 		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
3140 			      ATTR_FORCE);
3141 		if (!ia_valid)
3142 			return 0;
3143 	}
3144 
3145 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
3146 			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
3147 		return dentry_has_perm(cred, dentry, FILE__SETATTR);
3148 
3149 	if (selinux_policycap_openperm() &&
3150 	    inode->i_sb->s_magic != SOCKFS_MAGIC &&
3151 	    (ia_valid & ATTR_SIZE) &&
3152 	    !(ia_valid & ATTR_FILE))
3153 		av |= FILE__OPEN;
3154 
3155 	return dentry_has_perm(cred, dentry, av);
3156 }
3157 
selinux_inode_getattr(const struct path * path)3158 static int selinux_inode_getattr(const struct path *path)
3159 {
3160 	return path_has_perm(current_cred(), path, FILE__GETATTR);
3161 }
3162 
has_cap_mac_admin(bool audit)3163 static bool has_cap_mac_admin(bool audit)
3164 {
3165 	const struct cred *cred = current_cred();
3166 	unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT;
3167 
3168 	if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts))
3169 		return false;
3170 	if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true))
3171 		return false;
3172 	return true;
3173 }
3174 
selinux_inode_setxattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3175 static int selinux_inode_setxattr(struct mnt_idmap *idmap,
3176 				  struct dentry *dentry, const char *name,
3177 				  const void *value, size_t size, int flags)
3178 {
3179 	struct inode *inode = d_backing_inode(dentry);
3180 	struct inode_security_struct *isec;
3181 	struct superblock_security_struct *sbsec;
3182 	struct common_audit_data ad;
3183 	u32 newsid, sid = current_sid();
3184 	int rc = 0;
3185 
3186 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3187 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
3188 		if (rc)
3189 			return rc;
3190 
3191 		/* Not an attribute we recognize, so just check the
3192 		   ordinary setattr permission. */
3193 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3194 	}
3195 
3196 	if (!selinux_initialized())
3197 		return (inode_owner_or_capable(idmap, inode) ? 0 : -EPERM);
3198 
3199 	sbsec = selinux_superblock(inode->i_sb);
3200 	if (!(sbsec->flags & SBLABEL_MNT))
3201 		return -EOPNOTSUPP;
3202 
3203 	if (!inode_owner_or_capable(idmap, inode))
3204 		return -EPERM;
3205 
3206 	ad.type = LSM_AUDIT_DATA_DENTRY;
3207 	ad.u.dentry = dentry;
3208 
3209 	isec = backing_inode_security(dentry);
3210 	rc = avc_has_perm(sid, isec->sid, isec->sclass,
3211 			  FILE__RELABELFROM, &ad);
3212 	if (rc)
3213 		return rc;
3214 
3215 	rc = security_context_to_sid(value, size, &newsid,
3216 				     GFP_KERNEL);
3217 	if (rc == -EINVAL) {
3218 		if (!has_cap_mac_admin(true)) {
3219 			struct audit_buffer *ab;
3220 			size_t audit_size;
3221 
3222 			/* We strip a nul only if it is at the end, otherwise the
3223 			 * context contains a nul and we should audit that */
3224 			if (value) {
3225 				const char *str = value;
3226 
3227 				if (str[size - 1] == '\0')
3228 					audit_size = size - 1;
3229 				else
3230 					audit_size = size;
3231 			} else {
3232 				audit_size = 0;
3233 			}
3234 			ab = audit_log_start(audit_context(),
3235 					     GFP_ATOMIC, AUDIT_SELINUX_ERR);
3236 			if (!ab)
3237 				return rc;
3238 			audit_log_format(ab, "op=setxattr invalid_context=");
3239 			audit_log_n_untrustedstring(ab, value, audit_size);
3240 			audit_log_end(ab);
3241 
3242 			return rc;
3243 		}
3244 		rc = security_context_to_sid_force(value,
3245 						   size, &newsid);
3246 	}
3247 	if (rc)
3248 		return rc;
3249 
3250 	rc = avc_has_perm(sid, newsid, isec->sclass,
3251 			  FILE__RELABELTO, &ad);
3252 	if (rc)
3253 		return rc;
3254 
3255 	rc = security_validate_transition(isec->sid, newsid,
3256 					  sid, isec->sclass);
3257 	if (rc)
3258 		return rc;
3259 
3260 	return avc_has_perm(newsid,
3261 			    sbsec->sid,
3262 			    SECCLASS_FILESYSTEM,
3263 			    FILESYSTEM__ASSOCIATE,
3264 			    &ad);
3265 }
3266 
selinux_inode_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name,struct posix_acl * kacl)3267 static int selinux_inode_set_acl(struct mnt_idmap *idmap,
3268 				 struct dentry *dentry, const char *acl_name,
3269 				 struct posix_acl *kacl)
3270 {
3271 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3272 }
3273 
selinux_inode_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3274 static int selinux_inode_get_acl(struct mnt_idmap *idmap,
3275 				 struct dentry *dentry, const char *acl_name)
3276 {
3277 	return dentry_has_perm(current_cred(), dentry, FILE__GETATTR);
3278 }
3279 
selinux_inode_remove_acl(struct mnt_idmap * idmap,struct dentry * dentry,const char * acl_name)3280 static int selinux_inode_remove_acl(struct mnt_idmap *idmap,
3281 				    struct dentry *dentry, const char *acl_name)
3282 {
3283 	return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3284 }
3285 
selinux_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)3286 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3287 					const void *value, size_t size,
3288 					int flags)
3289 {
3290 	struct inode *inode = d_backing_inode(dentry);
3291 	struct inode_security_struct *isec;
3292 	u32 newsid;
3293 	int rc;
3294 
3295 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3296 		/* Not an attribute we recognize, so nothing to do. */
3297 		return;
3298 	}
3299 
3300 	if (!selinux_initialized()) {
3301 		/* If we haven't even been initialized, then we can't validate
3302 		 * against a policy, so leave the label as invalid. It may
3303 		 * resolve to a valid label on the next revalidation try if
3304 		 * we've since initialized.
3305 		 */
3306 		return;
3307 	}
3308 
3309 	rc = security_context_to_sid_force(value, size,
3310 					   &newsid);
3311 	if (rc) {
3312 		pr_err("SELinux:  unable to map context to SID"
3313 		       "for (%s, %lu), rc=%d\n",
3314 		       inode->i_sb->s_id, inode->i_ino, -rc);
3315 		return;
3316 	}
3317 
3318 	isec = backing_inode_security(dentry);
3319 	spin_lock(&isec->lock);
3320 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3321 	isec->sid = newsid;
3322 	isec->initialized = LABEL_INITIALIZED;
3323 	spin_unlock(&isec->lock);
3324 }
3325 
selinux_inode_getxattr(struct dentry * dentry,const char * name)3326 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
3327 {
3328 	const struct cred *cred = current_cred();
3329 
3330 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3331 }
3332 
selinux_inode_listxattr(struct dentry * dentry)3333 static int selinux_inode_listxattr(struct dentry *dentry)
3334 {
3335 	const struct cred *cred = current_cred();
3336 
3337 	return dentry_has_perm(cred, dentry, FILE__GETATTR);
3338 }
3339 
selinux_inode_removexattr(struct mnt_idmap * idmap,struct dentry * dentry,const char * name)3340 static int selinux_inode_removexattr(struct mnt_idmap *idmap,
3341 				     struct dentry *dentry, const char *name)
3342 {
3343 	if (strcmp(name, XATTR_NAME_SELINUX)) {
3344 		int rc = cap_inode_removexattr(idmap, dentry, name);
3345 		if (rc)
3346 			return rc;
3347 
3348 		/* Not an attribute we recognize, so just check the
3349 		   ordinary setattr permission. */
3350 		return dentry_has_perm(current_cred(), dentry, FILE__SETATTR);
3351 	}
3352 
3353 	if (!selinux_initialized())
3354 		return 0;
3355 
3356 	/* No one is allowed to remove a SELinux security label.
3357 	   You can change the label, but all data must be labeled. */
3358 	return -EACCES;
3359 }
3360 
selinux_path_notify(const struct path * path,u64 mask,unsigned int obj_type)3361 static int selinux_path_notify(const struct path *path, u64 mask,
3362 						unsigned int obj_type)
3363 {
3364 	int ret;
3365 	u32 perm;
3366 
3367 	struct common_audit_data ad;
3368 
3369 	ad.type = LSM_AUDIT_DATA_PATH;
3370 	ad.u.path = *path;
3371 
3372 	/*
3373 	 * Set permission needed based on the type of mark being set.
3374 	 * Performs an additional check for sb watches.
3375 	 */
3376 	switch (obj_type) {
3377 	case FSNOTIFY_OBJ_TYPE_VFSMOUNT:
3378 		perm = FILE__WATCH_MOUNT;
3379 		break;
3380 	case FSNOTIFY_OBJ_TYPE_SB:
3381 		perm = FILE__WATCH_SB;
3382 		ret = superblock_has_perm(current_cred(), path->dentry->d_sb,
3383 						FILESYSTEM__WATCH, &ad);
3384 		if (ret)
3385 			return ret;
3386 		break;
3387 	case FSNOTIFY_OBJ_TYPE_INODE:
3388 		perm = FILE__WATCH;
3389 		break;
3390 	default:
3391 		return -EINVAL;
3392 	}
3393 
3394 	/* blocking watches require the file:watch_with_perm permission */
3395 	if (mask & (ALL_FSNOTIFY_PERM_EVENTS))
3396 		perm |= FILE__WATCH_WITH_PERM;
3397 
3398 	/* watches on read-like events need the file:watch_reads permission */
3399 	if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE))
3400 		perm |= FILE__WATCH_READS;
3401 
3402 	return path_has_perm(current_cred(), path, perm);
3403 }
3404 
3405 /*
3406  * Copy the inode security context value to the user.
3407  *
3408  * Permission check is handled by selinux_inode_getxattr hook.
3409  */
selinux_inode_getsecurity(struct mnt_idmap * idmap,struct inode * inode,const char * name,void ** buffer,bool alloc)3410 static int selinux_inode_getsecurity(struct mnt_idmap *idmap,
3411 				     struct inode *inode, const char *name,
3412 				     void **buffer, bool alloc)
3413 {
3414 	u32 size;
3415 	int error;
3416 	char *context = NULL;
3417 	struct inode_security_struct *isec;
3418 
3419 	/*
3420 	 * If we're not initialized yet, then we can't validate contexts, so
3421 	 * just let vfs_getxattr fall back to using the on-disk xattr.
3422 	 */
3423 	if (!selinux_initialized() ||
3424 	    strcmp(name, XATTR_SELINUX_SUFFIX))
3425 		return -EOPNOTSUPP;
3426 
3427 	/*
3428 	 * If the caller has CAP_MAC_ADMIN, then get the raw context
3429 	 * value even if it is not defined by current policy; otherwise,
3430 	 * use the in-core value under current policy.
3431 	 * Use the non-auditing forms of the permission checks since
3432 	 * getxattr may be called by unprivileged processes commonly
3433 	 * and lack of permission just means that we fall back to the
3434 	 * in-core context value, not a denial.
3435 	 */
3436 	isec = inode_security(inode);
3437 	if (has_cap_mac_admin(false))
3438 		error = security_sid_to_context_force(isec->sid, &context,
3439 						      &size);
3440 	else
3441 		error = security_sid_to_context(isec->sid,
3442 						&context, &size);
3443 	if (error)
3444 		return error;
3445 	error = size;
3446 	if (alloc) {
3447 		*buffer = context;
3448 		goto out_nofree;
3449 	}
3450 	kfree(context);
3451 out_nofree:
3452 	return error;
3453 }
3454 
selinux_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)3455 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3456 				     const void *value, size_t size, int flags)
3457 {
3458 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3459 	struct superblock_security_struct *sbsec;
3460 	u32 newsid;
3461 	int rc;
3462 
3463 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
3464 		return -EOPNOTSUPP;
3465 
3466 	sbsec = selinux_superblock(inode->i_sb);
3467 	if (!(sbsec->flags & SBLABEL_MNT))
3468 		return -EOPNOTSUPP;
3469 
3470 	if (!value || !size)
3471 		return -EACCES;
3472 
3473 	rc = security_context_to_sid(value, size, &newsid,
3474 				     GFP_KERNEL);
3475 	if (rc)
3476 		return rc;
3477 
3478 	spin_lock(&isec->lock);
3479 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3480 	isec->sid = newsid;
3481 	isec->initialized = LABEL_INITIALIZED;
3482 	spin_unlock(&isec->lock);
3483 	return 0;
3484 }
3485 
selinux_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)3486 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
3487 {
3488 	const int len = sizeof(XATTR_NAME_SELINUX);
3489 
3490 	if (!selinux_initialized())
3491 		return 0;
3492 
3493 	if (buffer && len <= buffer_size)
3494 		memcpy(buffer, XATTR_NAME_SELINUX, len);
3495 	return len;
3496 }
3497 
selinux_inode_getsecid(struct inode * inode,u32 * secid)3498 static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3499 {
3500 	struct inode_security_struct *isec = inode_security_novalidate(inode);
3501 	*secid = isec->sid;
3502 }
3503 
selinux_inode_copy_up(struct dentry * src,struct cred ** new)3504 static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
3505 {
3506 	u32 sid;
3507 	struct task_security_struct *tsec;
3508 	struct cred *new_creds = *new;
3509 
3510 	if (new_creds == NULL) {
3511 		new_creds = prepare_creds();
3512 		if (!new_creds)
3513 			return -ENOMEM;
3514 	}
3515 
3516 	tsec = selinux_cred(new_creds);
3517 	/* Get label from overlay inode and set it in create_sid */
3518 	selinux_inode_getsecid(d_inode(src), &sid);
3519 	tsec->create_sid = sid;
3520 	*new = new_creds;
3521 	return 0;
3522 }
3523 
selinux_inode_copy_up_xattr(const char * name)3524 static int selinux_inode_copy_up_xattr(const char *name)
3525 {
3526 	/* The copy_up hook above sets the initial context on an inode, but we
3527 	 * don't then want to overwrite it by blindly copying all the lower
3528 	 * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
3529 	 */
3530 	if (strcmp(name, XATTR_NAME_SELINUX) == 0)
3531 		return 1; /* Discard */
3532 	/*
3533 	 * Any other attribute apart from SELINUX is not claimed, supported
3534 	 * by selinux.
3535 	 */
3536 	return -EOPNOTSUPP;
3537 }
3538 
3539 /* kernfs node operations */
3540 
selinux_kernfs_init_security(struct kernfs_node * kn_dir,struct kernfs_node * kn)3541 static int selinux_kernfs_init_security(struct kernfs_node *kn_dir,
3542 					struct kernfs_node *kn)
3543 {
3544 	const struct task_security_struct *tsec = selinux_cred(current_cred());
3545 	u32 parent_sid, newsid, clen;
3546 	int rc;
3547 	char *context;
3548 
3549 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, NULL, 0);
3550 	if (rc == -ENODATA)
3551 		return 0;
3552 	else if (rc < 0)
3553 		return rc;
3554 
3555 	clen = (u32)rc;
3556 	context = kmalloc(clen, GFP_KERNEL);
3557 	if (!context)
3558 		return -ENOMEM;
3559 
3560 	rc = kernfs_xattr_get(kn_dir, XATTR_NAME_SELINUX, context, clen);
3561 	if (rc < 0) {
3562 		kfree(context);
3563 		return rc;
3564 	}
3565 
3566 	rc = security_context_to_sid(context, clen, &parent_sid,
3567 				     GFP_KERNEL);
3568 	kfree(context);
3569 	if (rc)
3570 		return rc;
3571 
3572 	if (tsec->create_sid) {
3573 		newsid = tsec->create_sid;
3574 	} else {
3575 		u16 secclass = inode_mode_to_security_class(kn->mode);
3576 		struct qstr q;
3577 
3578 		q.name = kn->name;
3579 		q.hash_len = hashlen_string(kn_dir, kn->name);
3580 
3581 		rc = security_transition_sid(tsec->sid,
3582 					     parent_sid, secclass, &q,
3583 					     &newsid);
3584 		if (rc)
3585 			return rc;
3586 	}
3587 
3588 	rc = security_sid_to_context_force(newsid,
3589 					   &context, &clen);
3590 	if (rc)
3591 		return rc;
3592 
3593 	rc = kernfs_xattr_set(kn, XATTR_NAME_SELINUX, context, clen,
3594 			      XATTR_CREATE);
3595 	kfree(context);
3596 	return rc;
3597 }
3598 
3599 
3600 /* file security operations */
3601 
selinux_revalidate_file_permission(struct file * file,int mask)3602 static int selinux_revalidate_file_permission(struct file *file, int mask)
3603 {
3604 	const struct cred *cred = current_cred();
3605 	struct inode *inode = file_inode(file);
3606 
3607 	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
3608 	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
3609 		mask |= MAY_APPEND;
3610 
3611 	return file_has_perm(cred, file,
3612 			     file_mask_to_av(inode->i_mode, mask));
3613 }
3614 
selinux_file_permission(struct file * file,int mask)3615 static int selinux_file_permission(struct file *file, int mask)
3616 {
3617 	struct inode *inode = file_inode(file);
3618 	struct file_security_struct *fsec = selinux_file(file);
3619 	struct inode_security_struct *isec;
3620 	u32 sid = current_sid();
3621 
3622 	if (!mask)
3623 		/* No permission to check.  Existence test. */
3624 		return 0;
3625 
3626 	isec = inode_security(inode);
3627 	if (sid == fsec->sid && fsec->isid == isec->sid &&
3628 	    fsec->pseqno == avc_policy_seqno())
3629 		/* No change since file_open check. */
3630 		return 0;
3631 
3632 	return selinux_revalidate_file_permission(file, mask);
3633 }
3634 
selinux_file_alloc_security(struct file * file)3635 static int selinux_file_alloc_security(struct file *file)
3636 {
3637 	struct file_security_struct *fsec = selinux_file(file);
3638 	u32 sid = current_sid();
3639 
3640 	fsec->sid = sid;
3641 	fsec->fown_sid = sid;
3642 
3643 	return 0;
3644 }
3645 
3646 /*
3647  * Check whether a task has the ioctl permission and cmd
3648  * operation to an inode.
3649  */
ioctl_has_perm(const struct cred * cred,struct file * file,u32 requested,u16 cmd)3650 static int ioctl_has_perm(const struct cred *cred, struct file *file,
3651 		u32 requested, u16 cmd)
3652 {
3653 	struct common_audit_data ad;
3654 	struct file_security_struct *fsec = selinux_file(file);
3655 	struct inode *inode = file_inode(file);
3656 	struct inode_security_struct *isec;
3657 	struct lsm_ioctlop_audit ioctl;
3658 	u32 ssid = cred_sid(cred);
3659 	int rc;
3660 	u8 driver = cmd >> 8;
3661 	u8 xperm = cmd & 0xff;
3662 
3663 	ad.type = LSM_AUDIT_DATA_IOCTL_OP;
3664 	ad.u.op = &ioctl;
3665 	ad.u.op->cmd = cmd;
3666 	ad.u.op->path = file->f_path;
3667 
3668 	if (ssid != fsec->sid) {
3669 		rc = avc_has_perm(ssid, fsec->sid,
3670 				SECCLASS_FD,
3671 				FD__USE,
3672 				&ad);
3673 		if (rc)
3674 			goto out;
3675 	}
3676 
3677 	if (unlikely(IS_PRIVATE(inode)))
3678 		return 0;
3679 
3680 	isec = inode_security(inode);
3681 	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
3682 				    requested, driver, xperm, &ad);
3683 out:
3684 	return rc;
3685 }
3686 
selinux_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)3687 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3688 			      unsigned long arg)
3689 {
3690 	const struct cred *cred = current_cred();
3691 	int error = 0;
3692 
3693 	switch (cmd) {
3694 	case FIONREAD:
3695 	case FIBMAP:
3696 	case FIGETBSZ:
3697 	case FS_IOC_GETFLAGS:
3698 	case FS_IOC_GETVERSION:
3699 		error = file_has_perm(cred, file, FILE__GETATTR);
3700 		break;
3701 
3702 	case FS_IOC_SETFLAGS:
3703 	case FS_IOC_SETVERSION:
3704 		error = file_has_perm(cred, file, FILE__SETATTR);
3705 		break;
3706 
3707 	/* sys_ioctl() checks */
3708 	case FIONBIO:
3709 	case FIOASYNC:
3710 		error = file_has_perm(cred, file, 0);
3711 		break;
3712 
3713 	case KDSKBENT:
3714 	case KDSKBSENT:
3715 		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3716 					    CAP_OPT_NONE, true);
3717 		break;
3718 
3719 	case FIOCLEX:
3720 	case FIONCLEX:
3721 		if (!selinux_policycap_ioctl_skip_cloexec())
3722 			error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3723 		break;
3724 
3725 	/* default case assumes that the command will go
3726 	 * to the file's ioctl() function.
3727 	 */
3728 	default:
3729 		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3730 	}
3731 	return error;
3732 }
3733 
3734 static int default_noexec __ro_after_init;
3735 
file_map_prot_check(struct file * file,unsigned long prot,int shared)3736 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3737 {
3738 	const struct cred *cred = current_cred();
3739 	u32 sid = cred_sid(cred);
3740 	int rc = 0;
3741 
3742 	if (default_noexec &&
3743 	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
3744 				   (!shared && (prot & PROT_WRITE)))) {
3745 		/*
3746 		 * We are making executable an anonymous mapping or a
3747 		 * private file mapping that will also be writable.
3748 		 * This has an additional check.
3749 		 */
3750 		rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3751 				  PROCESS__EXECMEM, NULL);
3752 		if (rc)
3753 			goto error;
3754 	}
3755 
3756 	if (file) {
3757 		/* read access is always possible with a mapping */
3758 		u32 av = FILE__READ;
3759 
3760 		/* write access only matters if the mapping is shared */
3761 		if (shared && (prot & PROT_WRITE))
3762 			av |= FILE__WRITE;
3763 
3764 		if (prot & PROT_EXEC)
3765 			av |= FILE__EXECUTE;
3766 
3767 		return file_has_perm(cred, file, av);
3768 	}
3769 
3770 error:
3771 	return rc;
3772 }
3773 
selinux_mmap_addr(unsigned long addr)3774 static int selinux_mmap_addr(unsigned long addr)
3775 {
3776 	int rc = 0;
3777 
3778 	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3779 		u32 sid = current_sid();
3780 		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3781 				  MEMPROTECT__MMAP_ZERO, NULL);
3782 	}
3783 
3784 	return rc;
3785 }
3786 
selinux_mmap_file(struct file * file,unsigned long reqprot __always_unused,unsigned long prot,unsigned long flags)3787 static int selinux_mmap_file(struct file *file,
3788 			     unsigned long reqprot __always_unused,
3789 			     unsigned long prot, unsigned long flags)
3790 {
3791 	struct common_audit_data ad;
3792 	int rc;
3793 
3794 	if (file) {
3795 		ad.type = LSM_AUDIT_DATA_FILE;
3796 		ad.u.file = file;
3797 		rc = inode_has_perm(current_cred(), file_inode(file),
3798 				    FILE__MAP, &ad);
3799 		if (rc)
3800 			return rc;
3801 	}
3802 
3803 	return file_map_prot_check(file, prot,
3804 				   (flags & MAP_TYPE) == MAP_SHARED);
3805 }
3806 
selinux_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot __always_unused,unsigned long prot)3807 static int selinux_file_mprotect(struct vm_area_struct *vma,
3808 				 unsigned long reqprot __always_unused,
3809 				 unsigned long prot)
3810 {
3811 	const struct cred *cred = current_cred();
3812 	u32 sid = cred_sid(cred);
3813 
3814 	if (default_noexec &&
3815 	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3816 		int rc = 0;
3817 		if (vma_is_initial_heap(vma)) {
3818 			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3819 					  PROCESS__EXECHEAP, NULL);
3820 		} else if (!vma->vm_file && (vma_is_initial_stack(vma) ||
3821 			    vma_is_stack_for_current(vma))) {
3822 			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
3823 					  PROCESS__EXECSTACK, NULL);
3824 		} else if (vma->vm_file && vma->anon_vma) {
3825 			/*
3826 			 * We are making executable a file mapping that has
3827 			 * had some COW done. Since pages might have been
3828 			 * written, check ability to execute the possibly
3829 			 * modified content.  This typically should only
3830 			 * occur for text relocations.
3831 			 */
3832 			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3833 		}
3834 		if (rc)
3835 			return rc;
3836 	}
3837 
3838 	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3839 }
3840 
selinux_file_lock(struct file * file,unsigned int cmd)3841 static int selinux_file_lock(struct file *file, unsigned int cmd)
3842 {
3843 	const struct cred *cred = current_cred();
3844 
3845 	return file_has_perm(cred, file, FILE__LOCK);
3846 }
3847 
selinux_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)3848 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3849 			      unsigned long arg)
3850 {
3851 	const struct cred *cred = current_cred();
3852 	int err = 0;
3853 
3854 	switch (cmd) {
3855 	case F_SETFL:
3856 		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3857 			err = file_has_perm(cred, file, FILE__WRITE);
3858 			break;
3859 		}
3860 		fallthrough;
3861 	case F_SETOWN:
3862 	case F_SETSIG:
3863 	case F_GETFL:
3864 	case F_GETOWN:
3865 	case F_GETSIG:
3866 	case F_GETOWNER_UIDS:
3867 		/* Just check FD__USE permission */
3868 		err = file_has_perm(cred, file, 0);
3869 		break;
3870 	case F_GETLK:
3871 	case F_SETLK:
3872 	case F_SETLKW:
3873 	case F_OFD_GETLK:
3874 	case F_OFD_SETLK:
3875 	case F_OFD_SETLKW:
3876 #if BITS_PER_LONG == 32
3877 	case F_GETLK64:
3878 	case F_SETLK64:
3879 	case F_SETLKW64:
3880 #endif
3881 		err = file_has_perm(cred, file, FILE__LOCK);
3882 		break;
3883 	}
3884 
3885 	return err;
3886 }
3887 
selinux_file_set_fowner(struct file * file)3888 static void selinux_file_set_fowner(struct file *file)
3889 {
3890 	struct file_security_struct *fsec;
3891 
3892 	fsec = selinux_file(file);
3893 	fsec->fown_sid = current_sid();
3894 }
3895 
selinux_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)3896 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3897 				       struct fown_struct *fown, int signum)
3898 {
3899 	struct file *file;
3900 	u32 sid = task_sid_obj(tsk);
3901 	u32 perm;
3902 	struct file_security_struct *fsec;
3903 
3904 	/* struct fown_struct is never outside the context of a struct file */
3905 	file = container_of(fown, struct file, f_owner);
3906 
3907 	fsec = selinux_file(file);
3908 
3909 	if (!signum)
3910 		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3911 	else
3912 		perm = signal_to_av(signum);
3913 
3914 	return avc_has_perm(fsec->fown_sid, sid,
3915 			    SECCLASS_PROCESS, perm, NULL);
3916 }
3917 
selinux_file_receive(struct file * file)3918 static int selinux_file_receive(struct file *file)
3919 {
3920 	const struct cred *cred = current_cred();
3921 
3922 	return file_has_perm(cred, file, file_to_av(file));
3923 }
3924 
selinux_file_open(struct file * file)3925 static int selinux_file_open(struct file *file)
3926 {
3927 	struct file_security_struct *fsec;
3928 	struct inode_security_struct *isec;
3929 
3930 	fsec = selinux_file(file);
3931 	isec = inode_security(file_inode(file));
3932 	/*
3933 	 * Save inode label and policy sequence number
3934 	 * at open-time so that selinux_file_permission
3935 	 * can determine whether revalidation is necessary.
3936 	 * Task label is already saved in the file security
3937 	 * struct as its SID.
3938 	 */
3939 	fsec->isid = isec->sid;
3940 	fsec->pseqno = avc_policy_seqno();
3941 	/*
3942 	 * Since the inode label or policy seqno may have changed
3943 	 * between the selinux_inode_permission check and the saving
3944 	 * of state above, recheck that access is still permitted.
3945 	 * Otherwise, access might never be revalidated against the
3946 	 * new inode label or new policy.
3947 	 * This check is not redundant - do not remove.
3948 	 */
3949 	return file_path_has_perm(file->f_cred, file, open_file_to_av(file));
3950 }
3951 
3952 /* task security operations */
3953 
selinux_task_alloc(struct task_struct * task,unsigned long clone_flags)3954 static int selinux_task_alloc(struct task_struct *task,
3955 			      unsigned long clone_flags)
3956 {
3957 	u32 sid = current_sid();
3958 
3959 	return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
3960 }
3961 
3962 /*
3963  * prepare a new set of credentials for modification
3964  */
selinux_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)3965 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3966 				gfp_t gfp)
3967 {
3968 	const struct task_security_struct *old_tsec = selinux_cred(old);
3969 	struct task_security_struct *tsec = selinux_cred(new);
3970 
3971 	*tsec = *old_tsec;
3972 	return 0;
3973 }
3974 
3975 /*
3976  * transfer the SELinux data to a blank set of creds
3977  */
selinux_cred_transfer(struct cred * new,const struct cred * old)3978 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3979 {
3980 	const struct task_security_struct *old_tsec = selinux_cred(old);
3981 	struct task_security_struct *tsec = selinux_cred(new);
3982 
3983 	*tsec = *old_tsec;
3984 }
3985 
selinux_cred_getsecid(const struct cred * c,u32 * secid)3986 static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
3987 {
3988 	*secid = cred_sid(c);
3989 }
3990 
3991 /*
3992  * set the security data for a kernel service
3993  * - all the creation contexts are set to unlabelled
3994  */
selinux_kernel_act_as(struct cred * new,u32 secid)3995 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3996 {
3997 	struct task_security_struct *tsec = selinux_cred(new);
3998 	u32 sid = current_sid();
3999 	int ret;
4000 
4001 	ret = avc_has_perm(sid, secid,
4002 			   SECCLASS_KERNEL_SERVICE,
4003 			   KERNEL_SERVICE__USE_AS_OVERRIDE,
4004 			   NULL);
4005 	if (ret == 0) {
4006 		tsec->sid = secid;
4007 		tsec->create_sid = 0;
4008 		tsec->keycreate_sid = 0;
4009 		tsec->sockcreate_sid = 0;
4010 	}
4011 	return ret;
4012 }
4013 
4014 /*
4015  * set the file creation context in a security record to the same as the
4016  * objective context of the specified inode
4017  */
selinux_kernel_create_files_as(struct cred * new,struct inode * inode)4018 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
4019 {
4020 	struct inode_security_struct *isec = inode_security(inode);
4021 	struct task_security_struct *tsec = selinux_cred(new);
4022 	u32 sid = current_sid();
4023 	int ret;
4024 
4025 	ret = avc_has_perm(sid, isec->sid,
4026 			   SECCLASS_KERNEL_SERVICE,
4027 			   KERNEL_SERVICE__CREATE_FILES_AS,
4028 			   NULL);
4029 
4030 	if (ret == 0)
4031 		tsec->create_sid = isec->sid;
4032 	return ret;
4033 }
4034 
selinux_kernel_module_request(char * kmod_name)4035 static int selinux_kernel_module_request(char *kmod_name)
4036 {
4037 	struct common_audit_data ad;
4038 
4039 	ad.type = LSM_AUDIT_DATA_KMOD;
4040 	ad.u.kmod_name = kmod_name;
4041 
4042 	return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
4043 			    SYSTEM__MODULE_REQUEST, &ad);
4044 }
4045 
selinux_kernel_module_from_file(struct file * file)4046 static int selinux_kernel_module_from_file(struct file *file)
4047 {
4048 	struct common_audit_data ad;
4049 	struct inode_security_struct *isec;
4050 	struct file_security_struct *fsec;
4051 	u32 sid = current_sid();
4052 	int rc;
4053 
4054 	/* init_module */
4055 	if (file == NULL)
4056 		return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
4057 					SYSTEM__MODULE_LOAD, NULL);
4058 
4059 	/* finit_module */
4060 
4061 	ad.type = LSM_AUDIT_DATA_FILE;
4062 	ad.u.file = file;
4063 
4064 	fsec = selinux_file(file);
4065 	if (sid != fsec->sid) {
4066 		rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
4067 		if (rc)
4068 			return rc;
4069 	}
4070 
4071 	isec = inode_security(file_inode(file));
4072 	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
4073 				SYSTEM__MODULE_LOAD, &ad);
4074 }
4075 
selinux_kernel_read_file(struct file * file,enum kernel_read_file_id id,bool contents)4076 static int selinux_kernel_read_file(struct file *file,
4077 				    enum kernel_read_file_id id,
4078 				    bool contents)
4079 {
4080 	int rc = 0;
4081 
4082 	switch (id) {
4083 	case READING_MODULE:
4084 		rc = selinux_kernel_module_from_file(contents ? file : NULL);
4085 		break;
4086 	default:
4087 		break;
4088 	}
4089 
4090 	return rc;
4091 }
4092 
selinux_kernel_load_data(enum kernel_load_data_id id,bool contents)4093 static int selinux_kernel_load_data(enum kernel_load_data_id id, bool contents)
4094 {
4095 	int rc = 0;
4096 
4097 	switch (id) {
4098 	case LOADING_MODULE:
4099 		rc = selinux_kernel_module_from_file(NULL);
4100 		break;
4101 	default:
4102 		break;
4103 	}
4104 
4105 	return rc;
4106 }
4107 
selinux_task_setpgid(struct task_struct * p,pid_t pgid)4108 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
4109 {
4110 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4111 			    PROCESS__SETPGID, NULL);
4112 }
4113 
selinux_task_getpgid(struct task_struct * p)4114 static int selinux_task_getpgid(struct task_struct *p)
4115 {
4116 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4117 			    PROCESS__GETPGID, NULL);
4118 }
4119 
selinux_task_getsid(struct task_struct * p)4120 static int selinux_task_getsid(struct task_struct *p)
4121 {
4122 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4123 			    PROCESS__GETSESSION, NULL);
4124 }
4125 
selinux_current_getsecid_subj(u32 * secid)4126 static void selinux_current_getsecid_subj(u32 *secid)
4127 {
4128 	*secid = current_sid();
4129 }
4130 
selinux_task_getsecid_obj(struct task_struct * p,u32 * secid)4131 static void selinux_task_getsecid_obj(struct task_struct *p, u32 *secid)
4132 {
4133 	*secid = task_sid_obj(p);
4134 }
4135 
selinux_task_setnice(struct task_struct * p,int nice)4136 static int selinux_task_setnice(struct task_struct *p, int nice)
4137 {
4138 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4139 			    PROCESS__SETSCHED, NULL);
4140 }
4141 
selinux_task_setioprio(struct task_struct * p,int ioprio)4142 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
4143 {
4144 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4145 			    PROCESS__SETSCHED, NULL);
4146 }
4147 
selinux_task_getioprio(struct task_struct * p)4148 static int selinux_task_getioprio(struct task_struct *p)
4149 {
4150 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4151 			    PROCESS__GETSCHED, NULL);
4152 }
4153 
selinux_task_prlimit(const struct cred * cred,const struct cred * tcred,unsigned int flags)4154 static int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
4155 				unsigned int flags)
4156 {
4157 	u32 av = 0;
4158 
4159 	if (!flags)
4160 		return 0;
4161 	if (flags & LSM_PRLIMIT_WRITE)
4162 		av |= PROCESS__SETRLIMIT;
4163 	if (flags & LSM_PRLIMIT_READ)
4164 		av |= PROCESS__GETRLIMIT;
4165 	return avc_has_perm(cred_sid(cred), cred_sid(tcred),
4166 			    SECCLASS_PROCESS, av, NULL);
4167 }
4168 
selinux_task_setrlimit(struct task_struct * p,unsigned int resource,struct rlimit * new_rlim)4169 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
4170 		struct rlimit *new_rlim)
4171 {
4172 	struct rlimit *old_rlim = p->signal->rlim + resource;
4173 
4174 	/* Control the ability to change the hard limit (whether
4175 	   lowering or raising it), so that the hard limit can
4176 	   later be used as a safe reset point for the soft limit
4177 	   upon context transitions.  See selinux_bprm_committing_creds. */
4178 	if (old_rlim->rlim_max != new_rlim->rlim_max)
4179 		return avc_has_perm(current_sid(), task_sid_obj(p),
4180 				    SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
4181 
4182 	return 0;
4183 }
4184 
selinux_task_setscheduler(struct task_struct * p)4185 static int selinux_task_setscheduler(struct task_struct *p)
4186 {
4187 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4188 			    PROCESS__SETSCHED, NULL);
4189 }
4190 
selinux_task_getscheduler(struct task_struct * p)4191 static int selinux_task_getscheduler(struct task_struct *p)
4192 {
4193 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4194 			    PROCESS__GETSCHED, NULL);
4195 }
4196 
selinux_task_movememory(struct task_struct * p)4197 static int selinux_task_movememory(struct task_struct *p)
4198 {
4199 	return avc_has_perm(current_sid(), task_sid_obj(p), SECCLASS_PROCESS,
4200 			    PROCESS__SETSCHED, NULL);
4201 }
4202 
selinux_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)4203 static int selinux_task_kill(struct task_struct *p, struct kernel_siginfo *info,
4204 				int sig, const struct cred *cred)
4205 {
4206 	u32 secid;
4207 	u32 perm;
4208 
4209 	if (!sig)
4210 		perm = PROCESS__SIGNULL; /* null signal; existence test */
4211 	else
4212 		perm = signal_to_av(sig);
4213 	if (!cred)
4214 		secid = current_sid();
4215 	else
4216 		secid = cred_sid(cred);
4217 	return avc_has_perm(secid, task_sid_obj(p), SECCLASS_PROCESS, perm, NULL);
4218 }
4219 
selinux_task_to_inode(struct task_struct * p,struct inode * inode)4220 static void selinux_task_to_inode(struct task_struct *p,
4221 				  struct inode *inode)
4222 {
4223 	struct inode_security_struct *isec = selinux_inode(inode);
4224 	u32 sid = task_sid_obj(p);
4225 
4226 	spin_lock(&isec->lock);
4227 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
4228 	isec->sid = sid;
4229 	isec->initialized = LABEL_INITIALIZED;
4230 	spin_unlock(&isec->lock);
4231 }
4232 
selinux_userns_create(const struct cred * cred)4233 static int selinux_userns_create(const struct cred *cred)
4234 {
4235 	u32 sid = current_sid();
4236 
4237 	return avc_has_perm(sid, sid, SECCLASS_USER_NAMESPACE,
4238 			USER_NAMESPACE__CREATE, NULL);
4239 }
4240 
4241 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv4(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4242 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4243 			struct common_audit_data *ad, u8 *proto)
4244 {
4245 	int offset, ihlen, ret = -EINVAL;
4246 	struct iphdr _iph, *ih;
4247 
4248 	offset = skb_network_offset(skb);
4249 	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
4250 	if (ih == NULL)
4251 		goto out;
4252 
4253 	ihlen = ih->ihl * 4;
4254 	if (ihlen < sizeof(_iph))
4255 		goto out;
4256 
4257 	ad->u.net->v4info.saddr = ih->saddr;
4258 	ad->u.net->v4info.daddr = ih->daddr;
4259 	ret = 0;
4260 
4261 	if (proto)
4262 		*proto = ih->protocol;
4263 
4264 	switch (ih->protocol) {
4265 	case IPPROTO_TCP: {
4266 		struct tcphdr _tcph, *th;
4267 
4268 		if (ntohs(ih->frag_off) & IP_OFFSET)
4269 			break;
4270 
4271 		offset += ihlen;
4272 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4273 		if (th == NULL)
4274 			break;
4275 
4276 		ad->u.net->sport = th->source;
4277 		ad->u.net->dport = th->dest;
4278 		break;
4279 	}
4280 
4281 	case IPPROTO_UDP: {
4282 		struct udphdr _udph, *uh;
4283 
4284 		if (ntohs(ih->frag_off) & IP_OFFSET)
4285 			break;
4286 
4287 		offset += ihlen;
4288 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4289 		if (uh == NULL)
4290 			break;
4291 
4292 		ad->u.net->sport = uh->source;
4293 		ad->u.net->dport = uh->dest;
4294 		break;
4295 	}
4296 
4297 	case IPPROTO_DCCP: {
4298 		struct dccp_hdr _dccph, *dh;
4299 
4300 		if (ntohs(ih->frag_off) & IP_OFFSET)
4301 			break;
4302 
4303 		offset += ihlen;
4304 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4305 		if (dh == NULL)
4306 			break;
4307 
4308 		ad->u.net->sport = dh->dccph_sport;
4309 		ad->u.net->dport = dh->dccph_dport;
4310 		break;
4311 	}
4312 
4313 #if IS_ENABLED(CONFIG_IP_SCTP)
4314 	case IPPROTO_SCTP: {
4315 		struct sctphdr _sctph, *sh;
4316 
4317 		if (ntohs(ih->frag_off) & IP_OFFSET)
4318 			break;
4319 
4320 		offset += ihlen;
4321 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4322 		if (sh == NULL)
4323 			break;
4324 
4325 		ad->u.net->sport = sh->source;
4326 		ad->u.net->dport = sh->dest;
4327 		break;
4328 	}
4329 #endif
4330 	default:
4331 		break;
4332 	}
4333 out:
4334 	return ret;
4335 }
4336 
4337 #if IS_ENABLED(CONFIG_IPV6)
4338 
4339 /* Returns error only if unable to parse addresses */
selinux_parse_skb_ipv6(struct sk_buff * skb,struct common_audit_data * ad,u8 * proto)4340 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4341 			struct common_audit_data *ad, u8 *proto)
4342 {
4343 	u8 nexthdr;
4344 	int ret = -EINVAL, offset;
4345 	struct ipv6hdr _ipv6h, *ip6;
4346 	__be16 frag_off;
4347 
4348 	offset = skb_network_offset(skb);
4349 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
4350 	if (ip6 == NULL)
4351 		goto out;
4352 
4353 	ad->u.net->v6info.saddr = ip6->saddr;
4354 	ad->u.net->v6info.daddr = ip6->daddr;
4355 	ret = 0;
4356 
4357 	nexthdr = ip6->nexthdr;
4358 	offset += sizeof(_ipv6h);
4359 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
4360 	if (offset < 0)
4361 		goto out;
4362 
4363 	if (proto)
4364 		*proto = nexthdr;
4365 
4366 	switch (nexthdr) {
4367 	case IPPROTO_TCP: {
4368 		struct tcphdr _tcph, *th;
4369 
4370 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
4371 		if (th == NULL)
4372 			break;
4373 
4374 		ad->u.net->sport = th->source;
4375 		ad->u.net->dport = th->dest;
4376 		break;
4377 	}
4378 
4379 	case IPPROTO_UDP: {
4380 		struct udphdr _udph, *uh;
4381 
4382 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
4383 		if (uh == NULL)
4384 			break;
4385 
4386 		ad->u.net->sport = uh->source;
4387 		ad->u.net->dport = uh->dest;
4388 		break;
4389 	}
4390 
4391 	case IPPROTO_DCCP: {
4392 		struct dccp_hdr _dccph, *dh;
4393 
4394 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
4395 		if (dh == NULL)
4396 			break;
4397 
4398 		ad->u.net->sport = dh->dccph_sport;
4399 		ad->u.net->dport = dh->dccph_dport;
4400 		break;
4401 	}
4402 
4403 #if IS_ENABLED(CONFIG_IP_SCTP)
4404 	case IPPROTO_SCTP: {
4405 		struct sctphdr _sctph, *sh;
4406 
4407 		sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph);
4408 		if (sh == NULL)
4409 			break;
4410 
4411 		ad->u.net->sport = sh->source;
4412 		ad->u.net->dport = sh->dest;
4413 		break;
4414 	}
4415 #endif
4416 	/* includes fragments */
4417 	default:
4418 		break;
4419 	}
4420 out:
4421 	return ret;
4422 }
4423 
4424 #endif /* IPV6 */
4425 
selinux_parse_skb(struct sk_buff * skb,struct common_audit_data * ad,char ** _addrp,int src,u8 * proto)4426 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4427 			     char **_addrp, int src, u8 *proto)
4428 {
4429 	char *addrp;
4430 	int ret;
4431 
4432 	switch (ad->u.net->family) {
4433 	case PF_INET:
4434 		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4435 		if (ret)
4436 			goto parse_error;
4437 		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
4438 				       &ad->u.net->v4info.daddr);
4439 		goto okay;
4440 
4441 #if IS_ENABLED(CONFIG_IPV6)
4442 	case PF_INET6:
4443 		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4444 		if (ret)
4445 			goto parse_error;
4446 		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
4447 				       &ad->u.net->v6info.daddr);
4448 		goto okay;
4449 #endif	/* IPV6 */
4450 	default:
4451 		addrp = NULL;
4452 		goto okay;
4453 	}
4454 
4455 parse_error:
4456 	pr_warn(
4457 	       "SELinux: failure in selinux_parse_skb(),"
4458 	       " unable to parse packet\n");
4459 	return ret;
4460 
4461 okay:
4462 	if (_addrp)
4463 		*_addrp = addrp;
4464 	return 0;
4465 }
4466 
4467 /**
4468  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4469  * @skb: the packet
4470  * @family: protocol family
4471  * @sid: the packet's peer label SID
4472  *
4473  * Description:
4474  * Check the various different forms of network peer labeling and determine
4475  * the peer label/SID for the packet; most of the magic actually occurs in
4476  * the security server function security_net_peersid_cmp().  The function
4477  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
4478  * or -EACCES if @sid is invalid due to inconsistencies with the different
4479  * peer labels.
4480  *
4481  */
selinux_skb_peerlbl_sid(struct sk_buff * skb,u16 family,u32 * sid)4482 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4483 {
4484 	int err;
4485 	u32 xfrm_sid;
4486 	u32 nlbl_sid;
4487 	u32 nlbl_type;
4488 
4489 	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4490 	if (unlikely(err))
4491 		return -EACCES;
4492 	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
4493 	if (unlikely(err))
4494 		return -EACCES;
4495 
4496 	err = security_net_peersid_resolve(nlbl_sid,
4497 					   nlbl_type, xfrm_sid, sid);
4498 	if (unlikely(err)) {
4499 		pr_warn(
4500 		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
4501 		       " unable to determine packet's peer label\n");
4502 		return -EACCES;
4503 	}
4504 
4505 	return 0;
4506 }
4507 
4508 /**
4509  * selinux_conn_sid - Determine the child socket label for a connection
4510  * @sk_sid: the parent socket's SID
4511  * @skb_sid: the packet's SID
4512  * @conn_sid: the resulting connection SID
4513  *
4514  * If @skb_sid is valid then the user:role:type information from @sk_sid is
4515  * combined with the MLS information from @skb_sid in order to create
4516  * @conn_sid.  If @skb_sid is not valid then @conn_sid is simply a copy
4517  * of @sk_sid.  Returns zero on success, negative values on failure.
4518  *
4519  */
selinux_conn_sid(u32 sk_sid,u32 skb_sid,u32 * conn_sid)4520 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
4521 {
4522 	int err = 0;
4523 
4524 	if (skb_sid != SECSID_NULL)
4525 		err = security_sid_mls_copy(sk_sid, skb_sid,
4526 					    conn_sid);
4527 	else
4528 		*conn_sid = sk_sid;
4529 
4530 	return err;
4531 }
4532 
4533 /* socket security operations */
4534 
socket_sockcreate_sid(const struct task_security_struct * tsec,u16 secclass,u32 * socksid)4535 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
4536 				 u16 secclass, u32 *socksid)
4537 {
4538 	if (tsec->sockcreate_sid > SECSID_NULL) {
4539 		*socksid = tsec->sockcreate_sid;
4540 		return 0;
4541 	}
4542 
4543 	return security_transition_sid(tsec->sid, tsec->sid,
4544 				       secclass, NULL, socksid);
4545 }
4546 
sock_has_perm(struct sock * sk,u32 perms)4547 static int sock_has_perm(struct sock *sk, u32 perms)
4548 {
4549 	struct sk_security_struct *sksec = sk->sk_security;
4550 	struct common_audit_data ad;
4551 	struct lsm_network_audit net;
4552 
4553 	if (sksec->sid == SECINITSID_KERNEL)
4554 		return 0;
4555 
4556 	ad_net_init_from_sk(&ad, &net, sk);
4557 
4558 	return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
4559 			    &ad);
4560 }
4561 
selinux_socket_create(int family,int type,int protocol,int kern)4562 static int selinux_socket_create(int family, int type,
4563 				 int protocol, int kern)
4564 {
4565 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4566 	u32 newsid;
4567 	u16 secclass;
4568 	int rc;
4569 
4570 	if (kern)
4571 		return 0;
4572 
4573 	secclass = socket_type_to_security_class(family, type, protocol);
4574 	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
4575 	if (rc)
4576 		return rc;
4577 
4578 	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
4579 }
4580 
selinux_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)4581 static int selinux_socket_post_create(struct socket *sock, int family,
4582 				      int type, int protocol, int kern)
4583 {
4584 	const struct task_security_struct *tsec = selinux_cred(current_cred());
4585 	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4586 	struct sk_security_struct *sksec;
4587 	u16 sclass = socket_type_to_security_class(family, type, protocol);
4588 	u32 sid = SECINITSID_KERNEL;
4589 	int err = 0;
4590 
4591 	if (!kern) {
4592 		err = socket_sockcreate_sid(tsec, sclass, &sid);
4593 		if (err)
4594 			return err;
4595 	}
4596 
4597 	isec->sclass = sclass;
4598 	isec->sid = sid;
4599 	isec->initialized = LABEL_INITIALIZED;
4600 
4601 	if (sock->sk) {
4602 		sksec = sock->sk->sk_security;
4603 		sksec->sclass = sclass;
4604 		sksec->sid = sid;
4605 		/* Allows detection of the first association on this socket */
4606 		if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4607 			sksec->sctp_assoc_state = SCTP_ASSOC_UNSET;
4608 
4609 		err = selinux_netlbl_socket_post_create(sock->sk, family);
4610 	}
4611 
4612 	return err;
4613 }
4614 
selinux_socket_socketpair(struct socket * socka,struct socket * sockb)4615 static int selinux_socket_socketpair(struct socket *socka,
4616 				     struct socket *sockb)
4617 {
4618 	struct sk_security_struct *sksec_a = socka->sk->sk_security;
4619 	struct sk_security_struct *sksec_b = sockb->sk->sk_security;
4620 
4621 	sksec_a->peer_sid = sksec_b->sid;
4622 	sksec_b->peer_sid = sksec_a->sid;
4623 
4624 	return 0;
4625 }
4626 
4627 /* Range of port numbers used to automatically bind.
4628    Need to determine whether we should perform a name_bind
4629    permission check between the socket and the port number. */
4630 
selinux_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)4631 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
4632 {
4633 	struct sock *sk = sock->sk;
4634 	struct sk_security_struct *sksec = sk->sk_security;
4635 	u16 family;
4636 	int err;
4637 
4638 	err = sock_has_perm(sk, SOCKET__BIND);
4639 	if (err)
4640 		goto out;
4641 
4642 	/* If PF_INET or PF_INET6, check name_bind permission for the port. */
4643 	family = sk->sk_family;
4644 	if (family == PF_INET || family == PF_INET6) {
4645 		char *addrp;
4646 		struct common_audit_data ad;
4647 		struct lsm_network_audit net = {0,};
4648 		struct sockaddr_in *addr4 = NULL;
4649 		struct sockaddr_in6 *addr6 = NULL;
4650 		u16 family_sa;
4651 		unsigned short snum;
4652 		u32 sid, node_perm;
4653 
4654 		/*
4655 		 * sctp_bindx(3) calls via selinux_sctp_bind_connect()
4656 		 * that validates multiple binding addresses. Because of this
4657 		 * need to check address->sa_family as it is possible to have
4658 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4659 		 */
4660 		if (addrlen < offsetofend(struct sockaddr, sa_family))
4661 			return -EINVAL;
4662 		family_sa = address->sa_family;
4663 		switch (family_sa) {
4664 		case AF_UNSPEC:
4665 		case AF_INET:
4666 			if (addrlen < sizeof(struct sockaddr_in))
4667 				return -EINVAL;
4668 			addr4 = (struct sockaddr_in *)address;
4669 			if (family_sa == AF_UNSPEC) {
4670 				/* see __inet_bind(), we only want to allow
4671 				 * AF_UNSPEC if the address is INADDR_ANY
4672 				 */
4673 				if (addr4->sin_addr.s_addr != htonl(INADDR_ANY))
4674 					goto err_af;
4675 				family_sa = AF_INET;
4676 			}
4677 			snum = ntohs(addr4->sin_port);
4678 			addrp = (char *)&addr4->sin_addr.s_addr;
4679 			break;
4680 		case AF_INET6:
4681 			if (addrlen < SIN6_LEN_RFC2133)
4682 				return -EINVAL;
4683 			addr6 = (struct sockaddr_in6 *)address;
4684 			snum = ntohs(addr6->sin6_port);
4685 			addrp = (char *)&addr6->sin6_addr.s6_addr;
4686 			break;
4687 		default:
4688 			goto err_af;
4689 		}
4690 
4691 		ad.type = LSM_AUDIT_DATA_NET;
4692 		ad.u.net = &net;
4693 		ad.u.net->sport = htons(snum);
4694 		ad.u.net->family = family_sa;
4695 
4696 		if (snum) {
4697 			int low, high;
4698 
4699 			inet_get_local_port_range(sock_net(sk), &low, &high);
4700 
4701 			if (inet_port_requires_bind_service(sock_net(sk), snum) ||
4702 			    snum < low || snum > high) {
4703 				err = sel_netport_sid(sk->sk_protocol,
4704 						      snum, &sid);
4705 				if (err)
4706 					goto out;
4707 				err = avc_has_perm(sksec->sid, sid,
4708 						   sksec->sclass,
4709 						   SOCKET__NAME_BIND, &ad);
4710 				if (err)
4711 					goto out;
4712 			}
4713 		}
4714 
4715 		switch (sksec->sclass) {
4716 		case SECCLASS_TCP_SOCKET:
4717 			node_perm = TCP_SOCKET__NODE_BIND;
4718 			break;
4719 
4720 		case SECCLASS_UDP_SOCKET:
4721 			node_perm = UDP_SOCKET__NODE_BIND;
4722 			break;
4723 
4724 		case SECCLASS_DCCP_SOCKET:
4725 			node_perm = DCCP_SOCKET__NODE_BIND;
4726 			break;
4727 
4728 		case SECCLASS_SCTP_SOCKET:
4729 			node_perm = SCTP_SOCKET__NODE_BIND;
4730 			break;
4731 
4732 		default:
4733 			node_perm = RAWIP_SOCKET__NODE_BIND;
4734 			break;
4735 		}
4736 
4737 		err = sel_netnode_sid(addrp, family_sa, &sid);
4738 		if (err)
4739 			goto out;
4740 
4741 		if (family_sa == AF_INET)
4742 			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
4743 		else
4744 			ad.u.net->v6info.saddr = addr6->sin6_addr;
4745 
4746 		err = avc_has_perm(sksec->sid, sid,
4747 				   sksec->sclass, node_perm, &ad);
4748 		if (err)
4749 			goto out;
4750 	}
4751 out:
4752 	return err;
4753 err_af:
4754 	/* Note that SCTP services expect -EINVAL, others -EAFNOSUPPORT. */
4755 	if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4756 		return -EINVAL;
4757 	return -EAFNOSUPPORT;
4758 }
4759 
4760 /* This supports connect(2) and SCTP connect services such as sctp_connectx(3)
4761  * and sctp_sendmsg(3) as described in Documentation/security/SCTP.rst
4762  */
selinux_socket_connect_helper(struct socket * sock,struct sockaddr * address,int addrlen)4763 static int selinux_socket_connect_helper(struct socket *sock,
4764 					 struct sockaddr *address, int addrlen)
4765 {
4766 	struct sock *sk = sock->sk;
4767 	struct sk_security_struct *sksec = sk->sk_security;
4768 	int err;
4769 
4770 	err = sock_has_perm(sk, SOCKET__CONNECT);
4771 	if (err)
4772 		return err;
4773 	if (addrlen < offsetofend(struct sockaddr, sa_family))
4774 		return -EINVAL;
4775 
4776 	/* connect(AF_UNSPEC) has special handling, as it is a documented
4777 	 * way to disconnect the socket
4778 	 */
4779 	if (address->sa_family == AF_UNSPEC)
4780 		return 0;
4781 
4782 	/*
4783 	 * If a TCP, DCCP or SCTP socket, check name_connect permission
4784 	 * for the port.
4785 	 */
4786 	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
4787 	    sksec->sclass == SECCLASS_DCCP_SOCKET ||
4788 	    sksec->sclass == SECCLASS_SCTP_SOCKET) {
4789 		struct common_audit_data ad;
4790 		struct lsm_network_audit net = {0,};
4791 		struct sockaddr_in *addr4 = NULL;
4792 		struct sockaddr_in6 *addr6 = NULL;
4793 		unsigned short snum;
4794 		u32 sid, perm;
4795 
4796 		/* sctp_connectx(3) calls via selinux_sctp_bind_connect()
4797 		 * that validates multiple connect addresses. Because of this
4798 		 * need to check address->sa_family as it is possible to have
4799 		 * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET.
4800 		 */
4801 		switch (address->sa_family) {
4802 		case AF_INET:
4803 			addr4 = (struct sockaddr_in *)address;
4804 			if (addrlen < sizeof(struct sockaddr_in))
4805 				return -EINVAL;
4806 			snum = ntohs(addr4->sin_port);
4807 			break;
4808 		case AF_INET6:
4809 			addr6 = (struct sockaddr_in6 *)address;
4810 			if (addrlen < SIN6_LEN_RFC2133)
4811 				return -EINVAL;
4812 			snum = ntohs(addr6->sin6_port);
4813 			break;
4814 		default:
4815 			/* Note that SCTP services expect -EINVAL, whereas
4816 			 * others expect -EAFNOSUPPORT.
4817 			 */
4818 			if (sksec->sclass == SECCLASS_SCTP_SOCKET)
4819 				return -EINVAL;
4820 			else
4821 				return -EAFNOSUPPORT;
4822 		}
4823 
4824 		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4825 		if (err)
4826 			return err;
4827 
4828 		switch (sksec->sclass) {
4829 		case SECCLASS_TCP_SOCKET:
4830 			perm = TCP_SOCKET__NAME_CONNECT;
4831 			break;
4832 		case SECCLASS_DCCP_SOCKET:
4833 			perm = DCCP_SOCKET__NAME_CONNECT;
4834 			break;
4835 		case SECCLASS_SCTP_SOCKET:
4836 			perm = SCTP_SOCKET__NAME_CONNECT;
4837 			break;
4838 		}
4839 
4840 		ad.type = LSM_AUDIT_DATA_NET;
4841 		ad.u.net = &net;
4842 		ad.u.net->dport = htons(snum);
4843 		ad.u.net->family = address->sa_family;
4844 		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4845 		if (err)
4846 			return err;
4847 	}
4848 
4849 	return 0;
4850 }
4851 
4852 /* Supports connect(2), see comments in selinux_socket_connect_helper() */
selinux_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)4853 static int selinux_socket_connect(struct socket *sock,
4854 				  struct sockaddr *address, int addrlen)
4855 {
4856 	int err;
4857 	struct sock *sk = sock->sk;
4858 
4859 	err = selinux_socket_connect_helper(sock, address, addrlen);
4860 	if (err)
4861 		return err;
4862 
4863 	return selinux_netlbl_socket_connect(sk, address);
4864 }
4865 
selinux_socket_listen(struct socket * sock,int backlog)4866 static int selinux_socket_listen(struct socket *sock, int backlog)
4867 {
4868 	return sock_has_perm(sock->sk, SOCKET__LISTEN);
4869 }
4870 
selinux_socket_accept(struct socket * sock,struct socket * newsock)4871 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4872 {
4873 	int err;
4874 	struct inode_security_struct *isec;
4875 	struct inode_security_struct *newisec;
4876 	u16 sclass;
4877 	u32 sid;
4878 
4879 	err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
4880 	if (err)
4881 		return err;
4882 
4883 	isec = inode_security_novalidate(SOCK_INODE(sock));
4884 	spin_lock(&isec->lock);
4885 	sclass = isec->sclass;
4886 	sid = isec->sid;
4887 	spin_unlock(&isec->lock);
4888 
4889 	newisec = inode_security_novalidate(SOCK_INODE(newsock));
4890 	newisec->sclass = sclass;
4891 	newisec->sid = sid;
4892 	newisec->initialized = LABEL_INITIALIZED;
4893 
4894 	return 0;
4895 }
4896 
selinux_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)4897 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4898 				  int size)
4899 {
4900 	return sock_has_perm(sock->sk, SOCKET__WRITE);
4901 }
4902 
selinux_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)4903 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4904 				  int size, int flags)
4905 {
4906 	return sock_has_perm(sock->sk, SOCKET__READ);
4907 }
4908 
selinux_socket_getsockname(struct socket * sock)4909 static int selinux_socket_getsockname(struct socket *sock)
4910 {
4911 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
4912 }
4913 
selinux_socket_getpeername(struct socket * sock)4914 static int selinux_socket_getpeername(struct socket *sock)
4915 {
4916 	return sock_has_perm(sock->sk, SOCKET__GETATTR);
4917 }
4918 
selinux_socket_setsockopt(struct socket * sock,int level,int optname)4919 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4920 {
4921 	int err;
4922 
4923 	err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4924 	if (err)
4925 		return err;
4926 
4927 	return selinux_netlbl_socket_setsockopt(sock, level, optname);
4928 }
4929 
selinux_socket_getsockopt(struct socket * sock,int level,int optname)4930 static int selinux_socket_getsockopt(struct socket *sock, int level,
4931 				     int optname)
4932 {
4933 	return sock_has_perm(sock->sk, SOCKET__GETOPT);
4934 }
4935 
selinux_socket_shutdown(struct socket * sock,int how)4936 static int selinux_socket_shutdown(struct socket *sock, int how)
4937 {
4938 	return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
4939 }
4940 
selinux_socket_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)4941 static int selinux_socket_unix_stream_connect(struct sock *sock,
4942 					      struct sock *other,
4943 					      struct sock *newsk)
4944 {
4945 	struct sk_security_struct *sksec_sock = sock->sk_security;
4946 	struct sk_security_struct *sksec_other = other->sk_security;
4947 	struct sk_security_struct *sksec_new = newsk->sk_security;
4948 	struct common_audit_data ad;
4949 	struct lsm_network_audit net;
4950 	int err;
4951 
4952 	ad_net_init_from_sk(&ad, &net, other);
4953 
4954 	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4955 			   sksec_other->sclass,
4956 			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4957 	if (err)
4958 		return err;
4959 
4960 	/* server child socket */
4961 	sksec_new->peer_sid = sksec_sock->sid;
4962 	err = security_sid_mls_copy(sksec_other->sid,
4963 				    sksec_sock->sid, &sksec_new->sid);
4964 	if (err)
4965 		return err;
4966 
4967 	/* connecting socket */
4968 	sksec_sock->peer_sid = sksec_new->sid;
4969 
4970 	return 0;
4971 }
4972 
selinux_socket_unix_may_send(struct socket * sock,struct socket * other)4973 static int selinux_socket_unix_may_send(struct socket *sock,
4974 					struct socket *other)
4975 {
4976 	struct sk_security_struct *ssec = sock->sk->sk_security;
4977 	struct sk_security_struct *osec = other->sk->sk_security;
4978 	struct common_audit_data ad;
4979 	struct lsm_network_audit net;
4980 
4981 	ad_net_init_from_sk(&ad, &net, other->sk);
4982 
4983 	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4984 			    &ad);
4985 }
4986 
selinux_inet_sys_rcv_skb(struct net * ns,int ifindex,char * addrp,u16 family,u32 peer_sid,struct common_audit_data * ad)4987 static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
4988 				    char *addrp, u16 family, u32 peer_sid,
4989 				    struct common_audit_data *ad)
4990 {
4991 	int err;
4992 	u32 if_sid;
4993 	u32 node_sid;
4994 
4995 	err = sel_netif_sid(ns, ifindex, &if_sid);
4996 	if (err)
4997 		return err;
4998 	err = avc_has_perm(peer_sid, if_sid,
4999 			   SECCLASS_NETIF, NETIF__INGRESS, ad);
5000 	if (err)
5001 		return err;
5002 
5003 	err = sel_netnode_sid(addrp, family, &node_sid);
5004 	if (err)
5005 		return err;
5006 	return avc_has_perm(peer_sid, node_sid,
5007 			    SECCLASS_NODE, NODE__RECVFROM, ad);
5008 }
5009 
selinux_sock_rcv_skb_compat(struct sock * sk,struct sk_buff * skb,u16 family)5010 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
5011 				       u16 family)
5012 {
5013 	int err = 0;
5014 	struct sk_security_struct *sksec = sk->sk_security;
5015 	u32 sk_sid = sksec->sid;
5016 	struct common_audit_data ad;
5017 	struct lsm_network_audit net;
5018 	char *addrp;
5019 
5020 	ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5021 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5022 	if (err)
5023 		return err;
5024 
5025 	if (selinux_secmark_enabled()) {
5026 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5027 				   PACKET__RECV, &ad);
5028 		if (err)
5029 			return err;
5030 	}
5031 
5032 	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
5033 	if (err)
5034 		return err;
5035 	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
5036 
5037 	return err;
5038 }
5039 
selinux_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)5040 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
5041 {
5042 	int err, peerlbl_active, secmark_active;
5043 	struct sk_security_struct *sksec = sk->sk_security;
5044 	u16 family = sk->sk_family;
5045 	u32 sk_sid = sksec->sid;
5046 	struct common_audit_data ad;
5047 	struct lsm_network_audit net;
5048 	char *addrp;
5049 
5050 	if (family != PF_INET && family != PF_INET6)
5051 		return 0;
5052 
5053 	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
5054 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5055 		family = PF_INET;
5056 
5057 	/* If any sort of compatibility mode is enabled then handoff processing
5058 	 * to the selinux_sock_rcv_skb_compat() function to deal with the
5059 	 * special handling.  We do this in an attempt to keep this function
5060 	 * as fast and as clean as possible. */
5061 	if (!selinux_policycap_netpeer())
5062 		return selinux_sock_rcv_skb_compat(sk, skb, family);
5063 
5064 	secmark_active = selinux_secmark_enabled();
5065 	peerlbl_active = selinux_peerlbl_enabled();
5066 	if (!secmark_active && !peerlbl_active)
5067 		return 0;
5068 
5069 	ad_net_init_from_iif(&ad, &net, skb->skb_iif, family);
5070 	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
5071 	if (err)
5072 		return err;
5073 
5074 	if (peerlbl_active) {
5075 		u32 peer_sid;
5076 
5077 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
5078 		if (err)
5079 			return err;
5080 		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
5081 					       addrp, family, peer_sid, &ad);
5082 		if (err) {
5083 			selinux_netlbl_err(skb, family, err, 0);
5084 			return err;
5085 		}
5086 		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
5087 				   PEER__RECV, &ad);
5088 		if (err) {
5089 			selinux_netlbl_err(skb, family, err, 0);
5090 			return err;
5091 		}
5092 	}
5093 
5094 	if (secmark_active) {
5095 		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
5096 				   PACKET__RECV, &ad);
5097 		if (err)
5098 			return err;
5099 	}
5100 
5101 	return err;
5102 }
5103 
selinux_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)5104 static int selinux_socket_getpeersec_stream(struct socket *sock,
5105 					    sockptr_t optval, sockptr_t optlen,
5106 					    unsigned int len)
5107 {
5108 	int err = 0;
5109 	char *scontext = NULL;
5110 	u32 scontext_len;
5111 	struct sk_security_struct *sksec = sock->sk->sk_security;
5112 	u32 peer_sid = SECSID_NULL;
5113 
5114 	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
5115 	    sksec->sclass == SECCLASS_TCP_SOCKET ||
5116 	    sksec->sclass == SECCLASS_SCTP_SOCKET)
5117 		peer_sid = sksec->peer_sid;
5118 	if (peer_sid == SECSID_NULL)
5119 		return -ENOPROTOOPT;
5120 
5121 	err = security_sid_to_context(peer_sid, &scontext,
5122 				      &scontext_len);
5123 	if (err)
5124 		return err;
5125 	if (scontext_len > len) {
5126 		err = -ERANGE;
5127 		goto out_len;
5128 	}
5129 
5130 	if (copy_to_sockptr(optval, scontext, scontext_len))
5131 		err = -EFAULT;
5132 out_len:
5133 	if (copy_to_sockptr(optlen, &scontext_len, sizeof(scontext_len)))
5134 		err = -EFAULT;
5135 	kfree(scontext);
5136 	return err;
5137 }
5138 
selinux_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)5139 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
5140 {
5141 	u32 peer_secid = SECSID_NULL;
5142 	u16 family;
5143 	struct inode_security_struct *isec;
5144 
5145 	if (skb && skb->protocol == htons(ETH_P_IP))
5146 		family = PF_INET;
5147 	else if (skb && skb->protocol == htons(ETH_P_IPV6))
5148 		family = PF_INET6;
5149 	else if (sock)
5150 		family = sock->sk->sk_family;
5151 	else
5152 		goto out;
5153 
5154 	if (sock && family == PF_UNIX) {
5155 		isec = inode_security_novalidate(SOCK_INODE(sock));
5156 		peer_secid = isec->sid;
5157 	} else if (skb)
5158 		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
5159 
5160 out:
5161 	*secid = peer_secid;
5162 	if (peer_secid == SECSID_NULL)
5163 		return -EINVAL;
5164 	return 0;
5165 }
5166 
selinux_sk_alloc_security(struct sock * sk,int family,gfp_t priority)5167 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
5168 {
5169 	struct sk_security_struct *sksec;
5170 
5171 	sksec = kzalloc(sizeof(*sksec), priority);
5172 	if (!sksec)
5173 		return -ENOMEM;
5174 
5175 	sksec->peer_sid = SECINITSID_UNLABELED;
5176 	sksec->sid = SECINITSID_UNLABELED;
5177 	sksec->sclass = SECCLASS_SOCKET;
5178 	selinux_netlbl_sk_security_reset(sksec);
5179 	sk->sk_security = sksec;
5180 
5181 	return 0;
5182 }
5183 
selinux_sk_free_security(struct sock * sk)5184 static void selinux_sk_free_security(struct sock *sk)
5185 {
5186 	struct sk_security_struct *sksec = sk->sk_security;
5187 
5188 	sk->sk_security = NULL;
5189 	selinux_netlbl_sk_security_free(sksec);
5190 	kfree(sksec);
5191 }
5192 
selinux_sk_clone_security(const struct sock * sk,struct sock * newsk)5193 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
5194 {
5195 	struct sk_security_struct *sksec = sk->sk_security;
5196 	struct sk_security_struct *newsksec = newsk->sk_security;
5197 
5198 	newsksec->sid = sksec->sid;
5199 	newsksec->peer_sid = sksec->peer_sid;
5200 	newsksec->sclass = sksec->sclass;
5201 
5202 	selinux_netlbl_sk_security_reset(newsksec);
5203 }
5204 
selinux_sk_getsecid(const struct sock * sk,u32 * secid)5205 static void selinux_sk_getsecid(const struct sock *sk, u32 *secid)
5206 {
5207 	if (!sk)
5208 		*secid = SECINITSID_ANY_SOCKET;
5209 	else {
5210 		const struct sk_security_struct *sksec = sk->sk_security;
5211 
5212 		*secid = sksec->sid;
5213 	}
5214 }
5215 
selinux_sock_graft(struct sock * sk,struct socket * parent)5216 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
5217 {
5218 	struct inode_security_struct *isec =
5219 		inode_security_novalidate(SOCK_INODE(parent));
5220 	struct sk_security_struct *sksec = sk->sk_security;
5221 
5222 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
5223 	    sk->sk_family == PF_UNIX)
5224 		isec->sid = sksec->sid;
5225 	sksec->sclass = isec->sclass;
5226 }
5227 
5228 /*
5229  * Determines peer_secid for the asoc and updates socket's peer label
5230  * if it's the first association on the socket.
5231  */
selinux_sctp_process_new_assoc(struct sctp_association * asoc,struct sk_buff * skb)5232 static int selinux_sctp_process_new_assoc(struct sctp_association *asoc,
5233 					  struct sk_buff *skb)
5234 {
5235 	struct sock *sk = asoc->base.sk;
5236 	u16 family = sk->sk_family;
5237 	struct sk_security_struct *sksec = sk->sk_security;
5238 	struct common_audit_data ad;
5239 	struct lsm_network_audit net;
5240 	int err;
5241 
5242 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5243 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5244 		family = PF_INET;
5245 
5246 	if (selinux_peerlbl_enabled()) {
5247 		asoc->peer_secid = SECSID_NULL;
5248 
5249 		/* This will return peer_sid = SECSID_NULL if there are
5250 		 * no peer labels, see security_net_peersid_resolve().
5251 		 */
5252 		err = selinux_skb_peerlbl_sid(skb, family, &asoc->peer_secid);
5253 		if (err)
5254 			return err;
5255 
5256 		if (asoc->peer_secid == SECSID_NULL)
5257 			asoc->peer_secid = SECINITSID_UNLABELED;
5258 	} else {
5259 		asoc->peer_secid = SECINITSID_UNLABELED;
5260 	}
5261 
5262 	if (sksec->sctp_assoc_state == SCTP_ASSOC_UNSET) {
5263 		sksec->sctp_assoc_state = SCTP_ASSOC_SET;
5264 
5265 		/* Here as first association on socket. As the peer SID
5266 		 * was allowed by peer recv (and the netif/node checks),
5267 		 * then it is approved by policy and used as the primary
5268 		 * peer SID for getpeercon(3).
5269 		 */
5270 		sksec->peer_sid = asoc->peer_secid;
5271 	} else if (sksec->peer_sid != asoc->peer_secid) {
5272 		/* Other association peer SIDs are checked to enforce
5273 		 * consistency among the peer SIDs.
5274 		 */
5275 		ad_net_init_from_sk(&ad, &net, asoc->base.sk);
5276 		err = avc_has_perm(sksec->peer_sid, asoc->peer_secid,
5277 				   sksec->sclass, SCTP_SOCKET__ASSOCIATION,
5278 				   &ad);
5279 		if (err)
5280 			return err;
5281 	}
5282 	return 0;
5283 }
5284 
5285 /* Called whenever SCTP receives an INIT or COOKIE ECHO chunk. This
5286  * happens on an incoming connect(2), sctp_connectx(3) or
5287  * sctp_sendmsg(3) (with no association already present).
5288  */
selinux_sctp_assoc_request(struct sctp_association * asoc,struct sk_buff * skb)5289 static int selinux_sctp_assoc_request(struct sctp_association *asoc,
5290 				      struct sk_buff *skb)
5291 {
5292 	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5293 	u32 conn_sid;
5294 	int err;
5295 
5296 	if (!selinux_policycap_extsockclass())
5297 		return 0;
5298 
5299 	err = selinux_sctp_process_new_assoc(asoc, skb);
5300 	if (err)
5301 		return err;
5302 
5303 	/* Compute the MLS component for the connection and store
5304 	 * the information in asoc. This will be used by SCTP TCP type
5305 	 * sockets and peeled off connections as they cause a new
5306 	 * socket to be generated. selinux_sctp_sk_clone() will then
5307 	 * plug this into the new socket.
5308 	 */
5309 	err = selinux_conn_sid(sksec->sid, asoc->peer_secid, &conn_sid);
5310 	if (err)
5311 		return err;
5312 
5313 	asoc->secid = conn_sid;
5314 
5315 	/* Set any NetLabel labels including CIPSO/CALIPSO options. */
5316 	return selinux_netlbl_sctp_assoc_request(asoc, skb);
5317 }
5318 
5319 /* Called when SCTP receives a COOKIE ACK chunk as the final
5320  * response to an association request (initited by us).
5321  */
selinux_sctp_assoc_established(struct sctp_association * asoc,struct sk_buff * skb)5322 static int selinux_sctp_assoc_established(struct sctp_association *asoc,
5323 					  struct sk_buff *skb)
5324 {
5325 	struct sk_security_struct *sksec = asoc->base.sk->sk_security;
5326 
5327 	if (!selinux_policycap_extsockclass())
5328 		return 0;
5329 
5330 	/* Inherit secid from the parent socket - this will be picked up
5331 	 * by selinux_sctp_sk_clone() if the association gets peeled off
5332 	 * into a new socket.
5333 	 */
5334 	asoc->secid = sksec->sid;
5335 
5336 	return selinux_sctp_process_new_assoc(asoc, skb);
5337 }
5338 
5339 /* Check if sctp IPv4/IPv6 addresses are valid for binding or connecting
5340  * based on their @optname.
5341  */
selinux_sctp_bind_connect(struct sock * sk,int optname,struct sockaddr * address,int addrlen)5342 static int selinux_sctp_bind_connect(struct sock *sk, int optname,
5343 				     struct sockaddr *address,
5344 				     int addrlen)
5345 {
5346 	int len, err = 0, walk_size = 0;
5347 	void *addr_buf;
5348 	struct sockaddr *addr;
5349 	struct socket *sock;
5350 
5351 	if (!selinux_policycap_extsockclass())
5352 		return 0;
5353 
5354 	/* Process one or more addresses that may be IPv4 or IPv6 */
5355 	sock = sk->sk_socket;
5356 	addr_buf = address;
5357 
5358 	while (walk_size < addrlen) {
5359 		if (walk_size + sizeof(sa_family_t) > addrlen)
5360 			return -EINVAL;
5361 
5362 		addr = addr_buf;
5363 		switch (addr->sa_family) {
5364 		case AF_UNSPEC:
5365 		case AF_INET:
5366 			len = sizeof(struct sockaddr_in);
5367 			break;
5368 		case AF_INET6:
5369 			len = sizeof(struct sockaddr_in6);
5370 			break;
5371 		default:
5372 			return -EINVAL;
5373 		}
5374 
5375 		if (walk_size + len > addrlen)
5376 			return -EINVAL;
5377 
5378 		err = -EINVAL;
5379 		switch (optname) {
5380 		/* Bind checks */
5381 		case SCTP_PRIMARY_ADDR:
5382 		case SCTP_SET_PEER_PRIMARY_ADDR:
5383 		case SCTP_SOCKOPT_BINDX_ADD:
5384 			err = selinux_socket_bind(sock, addr, len);
5385 			break;
5386 		/* Connect checks */
5387 		case SCTP_SOCKOPT_CONNECTX:
5388 		case SCTP_PARAM_SET_PRIMARY:
5389 		case SCTP_PARAM_ADD_IP:
5390 		case SCTP_SENDMSG_CONNECT:
5391 			err = selinux_socket_connect_helper(sock, addr, len);
5392 			if (err)
5393 				return err;
5394 
5395 			/* As selinux_sctp_bind_connect() is called by the
5396 			 * SCTP protocol layer, the socket is already locked,
5397 			 * therefore selinux_netlbl_socket_connect_locked()
5398 			 * is called here. The situations handled are:
5399 			 * sctp_connectx(3), sctp_sendmsg(3), sendmsg(2),
5400 			 * whenever a new IP address is added or when a new
5401 			 * primary address is selected.
5402 			 * Note that an SCTP connect(2) call happens before
5403 			 * the SCTP protocol layer and is handled via
5404 			 * selinux_socket_connect().
5405 			 */
5406 			err = selinux_netlbl_socket_connect_locked(sk, addr);
5407 			break;
5408 		}
5409 
5410 		if (err)
5411 			return err;
5412 
5413 		addr_buf += len;
5414 		walk_size += len;
5415 	}
5416 
5417 	return 0;
5418 }
5419 
5420 /* Called whenever a new socket is created by accept(2) or sctp_peeloff(3). */
selinux_sctp_sk_clone(struct sctp_association * asoc,struct sock * sk,struct sock * newsk)5421 static void selinux_sctp_sk_clone(struct sctp_association *asoc, struct sock *sk,
5422 				  struct sock *newsk)
5423 {
5424 	struct sk_security_struct *sksec = sk->sk_security;
5425 	struct sk_security_struct *newsksec = newsk->sk_security;
5426 
5427 	/* If policy does not support SECCLASS_SCTP_SOCKET then call
5428 	 * the non-sctp clone version.
5429 	 */
5430 	if (!selinux_policycap_extsockclass())
5431 		return selinux_sk_clone_security(sk, newsk);
5432 
5433 	newsksec->sid = asoc->secid;
5434 	newsksec->peer_sid = asoc->peer_secid;
5435 	newsksec->sclass = sksec->sclass;
5436 	selinux_netlbl_sctp_sk_clone(sk, newsk);
5437 }
5438 
selinux_mptcp_add_subflow(struct sock * sk,struct sock * ssk)5439 static int selinux_mptcp_add_subflow(struct sock *sk, struct sock *ssk)
5440 {
5441 	struct sk_security_struct *ssksec = ssk->sk_security;
5442 	struct sk_security_struct *sksec = sk->sk_security;
5443 
5444 	ssksec->sclass = sksec->sclass;
5445 	ssksec->sid = sksec->sid;
5446 
5447 	/* replace the existing subflow label deleting the existing one
5448 	 * and re-recreating a new label using the updated context
5449 	 */
5450 	selinux_netlbl_sk_security_free(ssksec);
5451 	return selinux_netlbl_socket_post_create(ssk, ssk->sk_family);
5452 }
5453 
selinux_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)5454 static int selinux_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
5455 				     struct request_sock *req)
5456 {
5457 	struct sk_security_struct *sksec = sk->sk_security;
5458 	int err;
5459 	u16 family = req->rsk_ops->family;
5460 	u32 connsid;
5461 	u32 peersid;
5462 
5463 	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
5464 	if (err)
5465 		return err;
5466 	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
5467 	if (err)
5468 		return err;
5469 	req->secid = connsid;
5470 	req->peer_secid = peersid;
5471 
5472 	return selinux_netlbl_inet_conn_request(req, family);
5473 }
5474 
selinux_inet_csk_clone(struct sock * newsk,const struct request_sock * req)5475 static void selinux_inet_csk_clone(struct sock *newsk,
5476 				   const struct request_sock *req)
5477 {
5478 	struct sk_security_struct *newsksec = newsk->sk_security;
5479 
5480 	newsksec->sid = req->secid;
5481 	newsksec->peer_sid = req->peer_secid;
5482 	/* NOTE: Ideally, we should also get the isec->sid for the
5483 	   new socket in sync, but we don't have the isec available yet.
5484 	   So we will wait until sock_graft to do it, by which
5485 	   time it will have been created and available. */
5486 
5487 	/* We don't need to take any sort of lock here as we are the only
5488 	 * thread with access to newsksec */
5489 	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
5490 }
5491 
selinux_inet_conn_established(struct sock * sk,struct sk_buff * skb)5492 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
5493 {
5494 	u16 family = sk->sk_family;
5495 	struct sk_security_struct *sksec = sk->sk_security;
5496 
5497 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
5498 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
5499 		family = PF_INET;
5500 
5501 	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5502 }
5503 
selinux_secmark_relabel_packet(u32 sid)5504 static int selinux_secmark_relabel_packet(u32 sid)
5505 {
5506 	const struct task_security_struct *tsec;
5507 	u32 tsid;
5508 
5509 	tsec = selinux_cred(current_cred());
5510 	tsid = tsec->sid;
5511 
5512 	return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO,
5513 			    NULL);
5514 }
5515 
selinux_secmark_refcount_inc(void)5516 static void selinux_secmark_refcount_inc(void)
5517 {
5518 	atomic_inc(&selinux_secmark_refcount);
5519 }
5520 
selinux_secmark_refcount_dec(void)5521 static void selinux_secmark_refcount_dec(void)
5522 {
5523 	atomic_dec(&selinux_secmark_refcount);
5524 }
5525 
selinux_req_classify_flow(const struct request_sock * req,struct flowi_common * flic)5526 static void selinux_req_classify_flow(const struct request_sock *req,
5527 				      struct flowi_common *flic)
5528 {
5529 	flic->flowic_secid = req->secid;
5530 }
5531 
selinux_tun_dev_alloc_security(void ** security)5532 static int selinux_tun_dev_alloc_security(void **security)
5533 {
5534 	struct tun_security_struct *tunsec;
5535 
5536 	tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
5537 	if (!tunsec)
5538 		return -ENOMEM;
5539 	tunsec->sid = current_sid();
5540 
5541 	*security = tunsec;
5542 	return 0;
5543 }
5544 
selinux_tun_dev_free_security(void * security)5545 static void selinux_tun_dev_free_security(void *security)
5546 {
5547 	kfree(security);
5548 }
5549 
selinux_tun_dev_create(void)5550 static int selinux_tun_dev_create(void)
5551 {
5552 	u32 sid = current_sid();
5553 
5554 	/* we aren't taking into account the "sockcreate" SID since the socket
5555 	 * that is being created here is not a socket in the traditional sense,
5556 	 * instead it is a private sock, accessible only to the kernel, and
5557 	 * representing a wide range of network traffic spanning multiple
5558 	 * connections unlike traditional sockets - check the TUN driver to
5559 	 * get a better understanding of why this socket is special */
5560 
5561 	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
5562 			    NULL);
5563 }
5564 
selinux_tun_dev_attach_queue(void * security)5565 static int selinux_tun_dev_attach_queue(void *security)
5566 {
5567 	struct tun_security_struct *tunsec = security;
5568 
5569 	return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
5570 			    TUN_SOCKET__ATTACH_QUEUE, NULL);
5571 }
5572 
selinux_tun_dev_attach(struct sock * sk,void * security)5573 static int selinux_tun_dev_attach(struct sock *sk, void *security)
5574 {
5575 	struct tun_security_struct *tunsec = security;
5576 	struct sk_security_struct *sksec = sk->sk_security;
5577 
5578 	/* we don't currently perform any NetLabel based labeling here and it
5579 	 * isn't clear that we would want to do so anyway; while we could apply
5580 	 * labeling without the support of the TUN user the resulting labeled
5581 	 * traffic from the other end of the connection would almost certainly
5582 	 * cause confusion to the TUN user that had no idea network labeling
5583 	 * protocols were being used */
5584 
5585 	sksec->sid = tunsec->sid;
5586 	sksec->sclass = SECCLASS_TUN_SOCKET;
5587 
5588 	return 0;
5589 }
5590 
selinux_tun_dev_open(void * security)5591 static int selinux_tun_dev_open(void *security)
5592 {
5593 	struct tun_security_struct *tunsec = security;
5594 	u32 sid = current_sid();
5595 	int err;
5596 
5597 	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5598 			   TUN_SOCKET__RELABELFROM, NULL);
5599 	if (err)
5600 		return err;
5601 	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
5602 			   TUN_SOCKET__RELABELTO, NULL);
5603 	if (err)
5604 		return err;
5605 	tunsec->sid = sid;
5606 
5607 	return 0;
5608 }
5609 
5610 #ifdef CONFIG_NETFILTER
5611 
selinux_ip_forward(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5612 static unsigned int selinux_ip_forward(void *priv, struct sk_buff *skb,
5613 				       const struct nf_hook_state *state)
5614 {
5615 	int ifindex;
5616 	u16 family;
5617 	char *addrp;
5618 	u32 peer_sid;
5619 	struct common_audit_data ad;
5620 	struct lsm_network_audit net;
5621 	int secmark_active, peerlbl_active;
5622 
5623 	if (!selinux_policycap_netpeer())
5624 		return NF_ACCEPT;
5625 
5626 	secmark_active = selinux_secmark_enabled();
5627 	peerlbl_active = selinux_peerlbl_enabled();
5628 	if (!secmark_active && !peerlbl_active)
5629 		return NF_ACCEPT;
5630 
5631 	family = state->pf;
5632 	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
5633 		return NF_DROP;
5634 
5635 	ifindex = state->in->ifindex;
5636 	ad_net_init_from_iif(&ad, &net, ifindex, family);
5637 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
5638 		return NF_DROP;
5639 
5640 	if (peerlbl_active) {
5641 		int err;
5642 
5643 		err = selinux_inet_sys_rcv_skb(state->net, ifindex,
5644 					       addrp, family, peer_sid, &ad);
5645 		if (err) {
5646 			selinux_netlbl_err(skb, family, err, 1);
5647 			return NF_DROP;
5648 		}
5649 	}
5650 
5651 	if (secmark_active)
5652 		if (avc_has_perm(peer_sid, skb->secmark,
5653 				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
5654 			return NF_DROP;
5655 
5656 	if (netlbl_enabled())
5657 		/* we do this in the FORWARD path and not the POST_ROUTING
5658 		 * path because we want to make sure we apply the necessary
5659 		 * labeling before IPsec is applied so we can leverage AH
5660 		 * protection */
5661 		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
5662 			return NF_DROP;
5663 
5664 	return NF_ACCEPT;
5665 }
5666 
selinux_ip_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5667 static unsigned int selinux_ip_output(void *priv, struct sk_buff *skb,
5668 				      const struct nf_hook_state *state)
5669 {
5670 	struct sock *sk;
5671 	u32 sid;
5672 
5673 	if (!netlbl_enabled())
5674 		return NF_ACCEPT;
5675 
5676 	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
5677 	 * because we want to make sure we apply the necessary labeling
5678 	 * before IPsec is applied so we can leverage AH protection */
5679 	sk = skb->sk;
5680 	if (sk) {
5681 		struct sk_security_struct *sksec;
5682 
5683 		if (sk_listener(sk))
5684 			/* if the socket is the listening state then this
5685 			 * packet is a SYN-ACK packet which means it needs to
5686 			 * be labeled based on the connection/request_sock and
5687 			 * not the parent socket.  unfortunately, we can't
5688 			 * lookup the request_sock yet as it isn't queued on
5689 			 * the parent socket until after the SYN-ACK is sent.
5690 			 * the "solution" is to simply pass the packet as-is
5691 			 * as any IP option based labeling should be copied
5692 			 * from the initial connection request (in the IP
5693 			 * layer).  it is far from ideal, but until we get a
5694 			 * security label in the packet itself this is the
5695 			 * best we can do. */
5696 			return NF_ACCEPT;
5697 
5698 		/* standard practice, label using the parent socket */
5699 		sksec = sk->sk_security;
5700 		sid = sksec->sid;
5701 	} else
5702 		sid = SECINITSID_KERNEL;
5703 	if (selinux_netlbl_skbuff_setsid(skb, state->pf, sid) != 0)
5704 		return NF_DROP;
5705 
5706 	return NF_ACCEPT;
5707 }
5708 
5709 
selinux_ip_postroute_compat(struct sk_buff * skb,const struct nf_hook_state * state)5710 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
5711 					const struct nf_hook_state *state)
5712 {
5713 	struct sock *sk;
5714 	struct sk_security_struct *sksec;
5715 	struct common_audit_data ad;
5716 	struct lsm_network_audit net;
5717 	u8 proto = 0;
5718 
5719 	sk = skb_to_full_sk(skb);
5720 	if (sk == NULL)
5721 		return NF_ACCEPT;
5722 	sksec = sk->sk_security;
5723 
5724 	ad_net_init_from_iif(&ad, &net, state->out->ifindex, state->pf);
5725 	if (selinux_parse_skb(skb, &ad, NULL, 0, &proto))
5726 		return NF_DROP;
5727 
5728 	if (selinux_secmark_enabled())
5729 		if (avc_has_perm(sksec->sid, skb->secmark,
5730 				 SECCLASS_PACKET, PACKET__SEND, &ad))
5731 			return NF_DROP_ERR(-ECONNREFUSED);
5732 
5733 	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
5734 		return NF_DROP_ERR(-ECONNREFUSED);
5735 
5736 	return NF_ACCEPT;
5737 }
5738 
selinux_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)5739 static unsigned int selinux_ip_postroute(void *priv,
5740 					 struct sk_buff *skb,
5741 					 const struct nf_hook_state *state)
5742 {
5743 	u16 family;
5744 	u32 secmark_perm;
5745 	u32 peer_sid;
5746 	int ifindex;
5747 	struct sock *sk;
5748 	struct common_audit_data ad;
5749 	struct lsm_network_audit net;
5750 	char *addrp;
5751 	int secmark_active, peerlbl_active;
5752 
5753 	/* If any sort of compatibility mode is enabled then handoff processing
5754 	 * to the selinux_ip_postroute_compat() function to deal with the
5755 	 * special handling.  We do this in an attempt to keep this function
5756 	 * as fast and as clean as possible. */
5757 	if (!selinux_policycap_netpeer())
5758 		return selinux_ip_postroute_compat(skb, state);
5759 
5760 	secmark_active = selinux_secmark_enabled();
5761 	peerlbl_active = selinux_peerlbl_enabled();
5762 	if (!secmark_active && !peerlbl_active)
5763 		return NF_ACCEPT;
5764 
5765 	sk = skb_to_full_sk(skb);
5766 
5767 #ifdef CONFIG_XFRM
5768 	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
5769 	 * packet transformation so allow the packet to pass without any checks
5770 	 * since we'll have another chance to perform access control checks
5771 	 * when the packet is on it's final way out.
5772 	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5773 	 *       is NULL, in this case go ahead and apply access control.
5774 	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
5775 	 *       TCP listening state we cannot wait until the XFRM processing
5776 	 *       is done as we will miss out on the SA label if we do;
5777 	 *       unfortunately, this means more work, but it is only once per
5778 	 *       connection. */
5779 	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5780 	    !(sk && sk_listener(sk)))
5781 		return NF_ACCEPT;
5782 #endif
5783 
5784 	family = state->pf;
5785 	if (sk == NULL) {
5786 		/* Without an associated socket the packet is either coming
5787 		 * from the kernel or it is being forwarded; check the packet
5788 		 * to determine which and if the packet is being forwarded
5789 		 * query the packet directly to determine the security label. */
5790 		if (skb->skb_iif) {
5791 			secmark_perm = PACKET__FORWARD_OUT;
5792 			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5793 				return NF_DROP;
5794 		} else {
5795 			secmark_perm = PACKET__SEND;
5796 			peer_sid = SECINITSID_KERNEL;
5797 		}
5798 	} else if (sk_listener(sk)) {
5799 		/* Locally generated packet but the associated socket is in the
5800 		 * listening state which means this is a SYN-ACK packet.  In
5801 		 * this particular case the correct security label is assigned
5802 		 * to the connection/request_sock but unfortunately we can't
5803 		 * query the request_sock as it isn't queued on the parent
5804 		 * socket until after the SYN-ACK packet is sent; the only
5805 		 * viable choice is to regenerate the label like we do in
5806 		 * selinux_inet_conn_request().  See also selinux_ip_output()
5807 		 * for similar problems. */
5808 		u32 skb_sid;
5809 		struct sk_security_struct *sksec;
5810 
5811 		sksec = sk->sk_security;
5812 		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
5813 			return NF_DROP;
5814 		/* At this point, if the returned skb peerlbl is SECSID_NULL
5815 		 * and the packet has been through at least one XFRM
5816 		 * transformation then we must be dealing with the "final"
5817 		 * form of labeled IPsec packet; since we've already applied
5818 		 * all of our access controls on this packet we can safely
5819 		 * pass the packet. */
5820 		if (skb_sid == SECSID_NULL) {
5821 			switch (family) {
5822 			case PF_INET:
5823 				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
5824 					return NF_ACCEPT;
5825 				break;
5826 			case PF_INET6:
5827 				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
5828 					return NF_ACCEPT;
5829 				break;
5830 			default:
5831 				return NF_DROP_ERR(-ECONNREFUSED);
5832 			}
5833 		}
5834 		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
5835 			return NF_DROP;
5836 		secmark_perm = PACKET__SEND;
5837 	} else {
5838 		/* Locally generated packet, fetch the security label from the
5839 		 * associated socket. */
5840 		struct sk_security_struct *sksec = sk->sk_security;
5841 		peer_sid = sksec->sid;
5842 		secmark_perm = PACKET__SEND;
5843 	}
5844 
5845 	ifindex = state->out->ifindex;
5846 	ad_net_init_from_iif(&ad, &net, ifindex, family);
5847 	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5848 		return NF_DROP;
5849 
5850 	if (secmark_active)
5851 		if (avc_has_perm(peer_sid, skb->secmark,
5852 				 SECCLASS_PACKET, secmark_perm, &ad))
5853 			return NF_DROP_ERR(-ECONNREFUSED);
5854 
5855 	if (peerlbl_active) {
5856 		u32 if_sid;
5857 		u32 node_sid;
5858 
5859 		if (sel_netif_sid(state->net, ifindex, &if_sid))
5860 			return NF_DROP;
5861 		if (avc_has_perm(peer_sid, if_sid,
5862 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5863 			return NF_DROP_ERR(-ECONNREFUSED);
5864 
5865 		if (sel_netnode_sid(addrp, family, &node_sid))
5866 			return NF_DROP;
5867 		if (avc_has_perm(peer_sid, node_sid,
5868 				 SECCLASS_NODE, NODE__SENDTO, &ad))
5869 			return NF_DROP_ERR(-ECONNREFUSED);
5870 	}
5871 
5872 	return NF_ACCEPT;
5873 }
5874 #endif	/* CONFIG_NETFILTER */
5875 
selinux_netlink_send(struct sock * sk,struct sk_buff * skb)5876 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
5877 {
5878 	int rc = 0;
5879 	unsigned int msg_len;
5880 	unsigned int data_len = skb->len;
5881 	unsigned char *data = skb->data;
5882 	struct nlmsghdr *nlh;
5883 	struct sk_security_struct *sksec = sk->sk_security;
5884 	u16 sclass = sksec->sclass;
5885 	u32 perm;
5886 
5887 	while (data_len >= nlmsg_total_size(0)) {
5888 		nlh = (struct nlmsghdr *)data;
5889 
5890 		/* NOTE: the nlmsg_len field isn't reliably set by some netlink
5891 		 *       users which means we can't reject skb's with bogus
5892 		 *       length fields; our solution is to follow what
5893 		 *       netlink_rcv_skb() does and simply skip processing at
5894 		 *       messages with length fields that are clearly junk
5895 		 */
5896 		if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
5897 			return 0;
5898 
5899 		rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
5900 		if (rc == 0) {
5901 			rc = sock_has_perm(sk, perm);
5902 			if (rc)
5903 				return rc;
5904 		} else if (rc == -EINVAL) {
5905 			/* -EINVAL is a missing msg/perm mapping */
5906 			pr_warn_ratelimited("SELinux: unrecognized netlink"
5907 				" message: protocol=%hu nlmsg_type=%hu sclass=%s"
5908 				" pid=%d comm=%s\n",
5909 				sk->sk_protocol, nlh->nlmsg_type,
5910 				secclass_map[sclass - 1].name,
5911 				task_pid_nr(current), current->comm);
5912 			if (enforcing_enabled() &&
5913 			    !security_get_allow_unknown())
5914 				return rc;
5915 			rc = 0;
5916 		} else if (rc == -ENOENT) {
5917 			/* -ENOENT is a missing socket/class mapping, ignore */
5918 			rc = 0;
5919 		} else {
5920 			return rc;
5921 		}
5922 
5923 		/* move to the next message after applying netlink padding */
5924 		msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
5925 		if (msg_len >= data_len)
5926 			return 0;
5927 		data_len -= msg_len;
5928 		data += msg_len;
5929 	}
5930 
5931 	return rc;
5932 }
5933 
ipc_init_security(struct ipc_security_struct * isec,u16 sclass)5934 static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
5935 {
5936 	isec->sclass = sclass;
5937 	isec->sid = current_sid();
5938 }
5939 
ipc_has_perm(struct kern_ipc_perm * ipc_perms,u32 perms)5940 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5941 			u32 perms)
5942 {
5943 	struct ipc_security_struct *isec;
5944 	struct common_audit_data ad;
5945 	u32 sid = current_sid();
5946 
5947 	isec = selinux_ipc(ipc_perms);
5948 
5949 	ad.type = LSM_AUDIT_DATA_IPC;
5950 	ad.u.ipc_id = ipc_perms->key;
5951 
5952 	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
5953 }
5954 
selinux_msg_msg_alloc_security(struct msg_msg * msg)5955 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
5956 {
5957 	struct msg_security_struct *msec;
5958 
5959 	msec = selinux_msg_msg(msg);
5960 	msec->sid = SECINITSID_UNLABELED;
5961 
5962 	return 0;
5963 }
5964 
5965 /* message queue security operations */
selinux_msg_queue_alloc_security(struct kern_ipc_perm * msq)5966 static int selinux_msg_queue_alloc_security(struct kern_ipc_perm *msq)
5967 {
5968 	struct ipc_security_struct *isec;
5969 	struct common_audit_data ad;
5970 	u32 sid = current_sid();
5971 
5972 	isec = selinux_ipc(msq);
5973 	ipc_init_security(isec, SECCLASS_MSGQ);
5974 
5975 	ad.type = LSM_AUDIT_DATA_IPC;
5976 	ad.u.ipc_id = msq->key;
5977 
5978 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5979 			    MSGQ__CREATE, &ad);
5980 }
5981 
selinux_msg_queue_associate(struct kern_ipc_perm * msq,int msqflg)5982 static int selinux_msg_queue_associate(struct kern_ipc_perm *msq, int msqflg)
5983 {
5984 	struct ipc_security_struct *isec;
5985 	struct common_audit_data ad;
5986 	u32 sid = current_sid();
5987 
5988 	isec = selinux_ipc(msq);
5989 
5990 	ad.type = LSM_AUDIT_DATA_IPC;
5991 	ad.u.ipc_id = msq->key;
5992 
5993 	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5994 			    MSGQ__ASSOCIATE, &ad);
5995 }
5996 
selinux_msg_queue_msgctl(struct kern_ipc_perm * msq,int cmd)5997 static int selinux_msg_queue_msgctl(struct kern_ipc_perm *msq, int cmd)
5998 {
5999 	u32 perms;
6000 
6001 	switch (cmd) {
6002 	case IPC_INFO:
6003 	case MSG_INFO:
6004 		/* No specific object, just general system-wide information. */
6005 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6006 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6007 	case IPC_STAT:
6008 	case MSG_STAT:
6009 	case MSG_STAT_ANY:
6010 		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
6011 		break;
6012 	case IPC_SET:
6013 		perms = MSGQ__SETATTR;
6014 		break;
6015 	case IPC_RMID:
6016 		perms = MSGQ__DESTROY;
6017 		break;
6018 	default:
6019 		return 0;
6020 	}
6021 
6022 	return ipc_has_perm(msq, perms);
6023 }
6024 
selinux_msg_queue_msgsnd(struct kern_ipc_perm * msq,struct msg_msg * msg,int msqflg)6025 static int selinux_msg_queue_msgsnd(struct kern_ipc_perm *msq, struct msg_msg *msg, int msqflg)
6026 {
6027 	struct ipc_security_struct *isec;
6028 	struct msg_security_struct *msec;
6029 	struct common_audit_data ad;
6030 	u32 sid = current_sid();
6031 	int rc;
6032 
6033 	isec = selinux_ipc(msq);
6034 	msec = selinux_msg_msg(msg);
6035 
6036 	/*
6037 	 * First time through, need to assign label to the message
6038 	 */
6039 	if (msec->sid == SECINITSID_UNLABELED) {
6040 		/*
6041 		 * Compute new sid based on current process and
6042 		 * message queue this message will be stored in
6043 		 */
6044 		rc = security_transition_sid(sid, isec->sid,
6045 					     SECCLASS_MSG, NULL, &msec->sid);
6046 		if (rc)
6047 			return rc;
6048 	}
6049 
6050 	ad.type = LSM_AUDIT_DATA_IPC;
6051 	ad.u.ipc_id = msq->key;
6052 
6053 	/* Can this process write to the queue? */
6054 	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
6055 			  MSGQ__WRITE, &ad);
6056 	if (!rc)
6057 		/* Can this process send the message */
6058 		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
6059 				  MSG__SEND, &ad);
6060 	if (!rc)
6061 		/* Can the message be put in the queue? */
6062 		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
6063 				  MSGQ__ENQUEUE, &ad);
6064 
6065 	return rc;
6066 }
6067 
selinux_msg_queue_msgrcv(struct kern_ipc_perm * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)6068 static int selinux_msg_queue_msgrcv(struct kern_ipc_perm *msq, struct msg_msg *msg,
6069 				    struct task_struct *target,
6070 				    long type, int mode)
6071 {
6072 	struct ipc_security_struct *isec;
6073 	struct msg_security_struct *msec;
6074 	struct common_audit_data ad;
6075 	u32 sid = task_sid_obj(target);
6076 	int rc;
6077 
6078 	isec = selinux_ipc(msq);
6079 	msec = selinux_msg_msg(msg);
6080 
6081 	ad.type = LSM_AUDIT_DATA_IPC;
6082 	ad.u.ipc_id = msq->key;
6083 
6084 	rc = avc_has_perm(sid, isec->sid,
6085 			  SECCLASS_MSGQ, MSGQ__READ, &ad);
6086 	if (!rc)
6087 		rc = avc_has_perm(sid, msec->sid,
6088 				  SECCLASS_MSG, MSG__RECEIVE, &ad);
6089 	return rc;
6090 }
6091 
6092 /* Shared Memory security operations */
selinux_shm_alloc_security(struct kern_ipc_perm * shp)6093 static int selinux_shm_alloc_security(struct kern_ipc_perm *shp)
6094 {
6095 	struct ipc_security_struct *isec;
6096 	struct common_audit_data ad;
6097 	u32 sid = current_sid();
6098 
6099 	isec = selinux_ipc(shp);
6100 	ipc_init_security(isec, SECCLASS_SHM);
6101 
6102 	ad.type = LSM_AUDIT_DATA_IPC;
6103 	ad.u.ipc_id = shp->key;
6104 
6105 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6106 			    SHM__CREATE, &ad);
6107 }
6108 
selinux_shm_associate(struct kern_ipc_perm * shp,int shmflg)6109 static int selinux_shm_associate(struct kern_ipc_perm *shp, int shmflg)
6110 {
6111 	struct ipc_security_struct *isec;
6112 	struct common_audit_data ad;
6113 	u32 sid = current_sid();
6114 
6115 	isec = selinux_ipc(shp);
6116 
6117 	ad.type = LSM_AUDIT_DATA_IPC;
6118 	ad.u.ipc_id = shp->key;
6119 
6120 	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
6121 			    SHM__ASSOCIATE, &ad);
6122 }
6123 
6124 /* Note, at this point, shp is locked down */
selinux_shm_shmctl(struct kern_ipc_perm * shp,int cmd)6125 static int selinux_shm_shmctl(struct kern_ipc_perm *shp, int cmd)
6126 {
6127 	u32 perms;
6128 
6129 	switch (cmd) {
6130 	case IPC_INFO:
6131 	case SHM_INFO:
6132 		/* No specific object, just general system-wide information. */
6133 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6134 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6135 	case IPC_STAT:
6136 	case SHM_STAT:
6137 	case SHM_STAT_ANY:
6138 		perms = SHM__GETATTR | SHM__ASSOCIATE;
6139 		break;
6140 	case IPC_SET:
6141 		perms = SHM__SETATTR;
6142 		break;
6143 	case SHM_LOCK:
6144 	case SHM_UNLOCK:
6145 		perms = SHM__LOCK;
6146 		break;
6147 	case IPC_RMID:
6148 		perms = SHM__DESTROY;
6149 		break;
6150 	default:
6151 		return 0;
6152 	}
6153 
6154 	return ipc_has_perm(shp, perms);
6155 }
6156 
selinux_shm_shmat(struct kern_ipc_perm * shp,char __user * shmaddr,int shmflg)6157 static int selinux_shm_shmat(struct kern_ipc_perm *shp,
6158 			     char __user *shmaddr, int shmflg)
6159 {
6160 	u32 perms;
6161 
6162 	if (shmflg & SHM_RDONLY)
6163 		perms = SHM__READ;
6164 	else
6165 		perms = SHM__READ | SHM__WRITE;
6166 
6167 	return ipc_has_perm(shp, perms);
6168 }
6169 
6170 /* Semaphore security operations */
selinux_sem_alloc_security(struct kern_ipc_perm * sma)6171 static int selinux_sem_alloc_security(struct kern_ipc_perm *sma)
6172 {
6173 	struct ipc_security_struct *isec;
6174 	struct common_audit_data ad;
6175 	u32 sid = current_sid();
6176 
6177 	isec = selinux_ipc(sma);
6178 	ipc_init_security(isec, SECCLASS_SEM);
6179 
6180 	ad.type = LSM_AUDIT_DATA_IPC;
6181 	ad.u.ipc_id = sma->key;
6182 
6183 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6184 			    SEM__CREATE, &ad);
6185 }
6186 
selinux_sem_associate(struct kern_ipc_perm * sma,int semflg)6187 static int selinux_sem_associate(struct kern_ipc_perm *sma, int semflg)
6188 {
6189 	struct ipc_security_struct *isec;
6190 	struct common_audit_data ad;
6191 	u32 sid = current_sid();
6192 
6193 	isec = selinux_ipc(sma);
6194 
6195 	ad.type = LSM_AUDIT_DATA_IPC;
6196 	ad.u.ipc_id = sma->key;
6197 
6198 	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
6199 			    SEM__ASSOCIATE, &ad);
6200 }
6201 
6202 /* Note, at this point, sma is locked down */
selinux_sem_semctl(struct kern_ipc_perm * sma,int cmd)6203 static int selinux_sem_semctl(struct kern_ipc_perm *sma, int cmd)
6204 {
6205 	int err;
6206 	u32 perms;
6207 
6208 	switch (cmd) {
6209 	case IPC_INFO:
6210 	case SEM_INFO:
6211 		/* No specific object, just general system-wide information. */
6212 		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
6213 				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
6214 	case GETPID:
6215 	case GETNCNT:
6216 	case GETZCNT:
6217 		perms = SEM__GETATTR;
6218 		break;
6219 	case GETVAL:
6220 	case GETALL:
6221 		perms = SEM__READ;
6222 		break;
6223 	case SETVAL:
6224 	case SETALL:
6225 		perms = SEM__WRITE;
6226 		break;
6227 	case IPC_RMID:
6228 		perms = SEM__DESTROY;
6229 		break;
6230 	case IPC_SET:
6231 		perms = SEM__SETATTR;
6232 		break;
6233 	case IPC_STAT:
6234 	case SEM_STAT:
6235 	case SEM_STAT_ANY:
6236 		perms = SEM__GETATTR | SEM__ASSOCIATE;
6237 		break;
6238 	default:
6239 		return 0;
6240 	}
6241 
6242 	err = ipc_has_perm(sma, perms);
6243 	return err;
6244 }
6245 
selinux_sem_semop(struct kern_ipc_perm * sma,struct sembuf * sops,unsigned nsops,int alter)6246 static int selinux_sem_semop(struct kern_ipc_perm *sma,
6247 			     struct sembuf *sops, unsigned nsops, int alter)
6248 {
6249 	u32 perms;
6250 
6251 	if (alter)
6252 		perms = SEM__READ | SEM__WRITE;
6253 	else
6254 		perms = SEM__READ;
6255 
6256 	return ipc_has_perm(sma, perms);
6257 }
6258 
selinux_ipc_permission(struct kern_ipc_perm * ipcp,short flag)6259 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
6260 {
6261 	u32 av = 0;
6262 
6263 	av = 0;
6264 	if (flag & S_IRUGO)
6265 		av |= IPC__UNIX_READ;
6266 	if (flag & S_IWUGO)
6267 		av |= IPC__UNIX_WRITE;
6268 
6269 	if (av == 0)
6270 		return 0;
6271 
6272 	return ipc_has_perm(ipcp, av);
6273 }
6274 
selinux_ipc_getsecid(struct kern_ipc_perm * ipcp,u32 * secid)6275 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
6276 {
6277 	struct ipc_security_struct *isec = selinux_ipc(ipcp);
6278 	*secid = isec->sid;
6279 }
6280 
selinux_d_instantiate(struct dentry * dentry,struct inode * inode)6281 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
6282 {
6283 	if (inode)
6284 		inode_doinit_with_dentry(inode, dentry);
6285 }
6286 
selinux_getprocattr(struct task_struct * p,const char * name,char ** value)6287 static int selinux_getprocattr(struct task_struct *p,
6288 			       const char *name, char **value)
6289 {
6290 	const struct task_security_struct *__tsec;
6291 	u32 sid;
6292 	int error;
6293 	unsigned len;
6294 
6295 	rcu_read_lock();
6296 	__tsec = selinux_cred(__task_cred(p));
6297 
6298 	if (current != p) {
6299 		error = avc_has_perm(current_sid(), __tsec->sid,
6300 				     SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
6301 		if (error)
6302 			goto bad;
6303 	}
6304 
6305 	if (!strcmp(name, "current"))
6306 		sid = __tsec->sid;
6307 	else if (!strcmp(name, "prev"))
6308 		sid = __tsec->osid;
6309 	else if (!strcmp(name, "exec"))
6310 		sid = __tsec->exec_sid;
6311 	else if (!strcmp(name, "fscreate"))
6312 		sid = __tsec->create_sid;
6313 	else if (!strcmp(name, "keycreate"))
6314 		sid = __tsec->keycreate_sid;
6315 	else if (!strcmp(name, "sockcreate"))
6316 		sid = __tsec->sockcreate_sid;
6317 	else {
6318 		error = -EINVAL;
6319 		goto bad;
6320 	}
6321 	rcu_read_unlock();
6322 
6323 	if (!sid)
6324 		return 0;
6325 
6326 	error = security_sid_to_context(sid, value, &len);
6327 	if (error)
6328 		return error;
6329 	return len;
6330 
6331 bad:
6332 	rcu_read_unlock();
6333 	return error;
6334 }
6335 
selinux_setprocattr(const char * name,void * value,size_t size)6336 static int selinux_setprocattr(const char *name, void *value, size_t size)
6337 {
6338 	struct task_security_struct *tsec;
6339 	struct cred *new;
6340 	u32 mysid = current_sid(), sid = 0, ptsid;
6341 	int error;
6342 	char *str = value;
6343 
6344 	/*
6345 	 * Basic control over ability to set these attributes at all.
6346 	 */
6347 	if (!strcmp(name, "exec"))
6348 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6349 				     PROCESS__SETEXEC, NULL);
6350 	else if (!strcmp(name, "fscreate"))
6351 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6352 				     PROCESS__SETFSCREATE, NULL);
6353 	else if (!strcmp(name, "keycreate"))
6354 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6355 				     PROCESS__SETKEYCREATE, NULL);
6356 	else if (!strcmp(name, "sockcreate"))
6357 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6358 				     PROCESS__SETSOCKCREATE, NULL);
6359 	else if (!strcmp(name, "current"))
6360 		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
6361 				     PROCESS__SETCURRENT, NULL);
6362 	else
6363 		error = -EINVAL;
6364 	if (error)
6365 		return error;
6366 
6367 	/* Obtain a SID for the context, if one was specified. */
6368 	if (size && str[0] && str[0] != '\n') {
6369 		if (str[size-1] == '\n') {
6370 			str[size-1] = 0;
6371 			size--;
6372 		}
6373 		error = security_context_to_sid(value, size,
6374 						&sid, GFP_KERNEL);
6375 		if (error == -EINVAL && !strcmp(name, "fscreate")) {
6376 			if (!has_cap_mac_admin(true)) {
6377 				struct audit_buffer *ab;
6378 				size_t audit_size;
6379 
6380 				/* We strip a nul only if it is at the end, otherwise the
6381 				 * context contains a nul and we should audit that */
6382 				if (str[size - 1] == '\0')
6383 					audit_size = size - 1;
6384 				else
6385 					audit_size = size;
6386 				ab = audit_log_start(audit_context(),
6387 						     GFP_ATOMIC,
6388 						     AUDIT_SELINUX_ERR);
6389 				if (!ab)
6390 					return error;
6391 				audit_log_format(ab, "op=fscreate invalid_context=");
6392 				audit_log_n_untrustedstring(ab, value, audit_size);
6393 				audit_log_end(ab);
6394 
6395 				return error;
6396 			}
6397 			error = security_context_to_sid_force(value, size,
6398 							&sid);
6399 		}
6400 		if (error)
6401 			return error;
6402 	}
6403 
6404 	new = prepare_creds();
6405 	if (!new)
6406 		return -ENOMEM;
6407 
6408 	/* Permission checking based on the specified context is
6409 	   performed during the actual operation (execve,
6410 	   open/mkdir/...), when we know the full context of the
6411 	   operation.  See selinux_bprm_creds_for_exec for the execve
6412 	   checks and may_create for the file creation checks. The
6413 	   operation will then fail if the context is not permitted. */
6414 	tsec = selinux_cred(new);
6415 	if (!strcmp(name, "exec")) {
6416 		tsec->exec_sid = sid;
6417 	} else if (!strcmp(name, "fscreate")) {
6418 		tsec->create_sid = sid;
6419 	} else if (!strcmp(name, "keycreate")) {
6420 		if (sid) {
6421 			error = avc_has_perm(mysid, sid,
6422 					     SECCLASS_KEY, KEY__CREATE, NULL);
6423 			if (error)
6424 				goto abort_change;
6425 		}
6426 		tsec->keycreate_sid = sid;
6427 	} else if (!strcmp(name, "sockcreate")) {
6428 		tsec->sockcreate_sid = sid;
6429 	} else if (!strcmp(name, "current")) {
6430 		error = -EINVAL;
6431 		if (sid == 0)
6432 			goto abort_change;
6433 
6434 		/* Only allow single threaded processes to change context */
6435 		if (!current_is_single_threaded()) {
6436 			error = security_bounded_transition(tsec->sid, sid);
6437 			if (error)
6438 				goto abort_change;
6439 		}
6440 
6441 		/* Check permissions for the transition. */
6442 		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6443 				     PROCESS__DYNTRANSITION, NULL);
6444 		if (error)
6445 			goto abort_change;
6446 
6447 		/* Check for ptracing, and update the task SID if ok.
6448 		   Otherwise, leave SID unchanged and fail. */
6449 		ptsid = ptrace_parent_sid();
6450 		if (ptsid != 0) {
6451 			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
6452 					     PROCESS__PTRACE, NULL);
6453 			if (error)
6454 				goto abort_change;
6455 		}
6456 
6457 		tsec->sid = sid;
6458 	} else {
6459 		error = -EINVAL;
6460 		goto abort_change;
6461 	}
6462 
6463 	commit_creds(new);
6464 	return size;
6465 
6466 abort_change:
6467 	abort_creds(new);
6468 	return error;
6469 }
6470 
selinux_ismaclabel(const char * name)6471 static int selinux_ismaclabel(const char *name)
6472 {
6473 	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
6474 }
6475 
selinux_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)6476 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
6477 {
6478 	return security_sid_to_context(secid,
6479 				       secdata, seclen);
6480 }
6481 
selinux_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)6482 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6483 {
6484 	return security_context_to_sid(secdata, seclen,
6485 				       secid, GFP_KERNEL);
6486 }
6487 
selinux_release_secctx(char * secdata,u32 seclen)6488 static void selinux_release_secctx(char *secdata, u32 seclen)
6489 {
6490 	kfree(secdata);
6491 }
6492 
selinux_inode_invalidate_secctx(struct inode * inode)6493 static void selinux_inode_invalidate_secctx(struct inode *inode)
6494 {
6495 	struct inode_security_struct *isec = selinux_inode(inode);
6496 
6497 	spin_lock(&isec->lock);
6498 	isec->initialized = LABEL_INVALID;
6499 	spin_unlock(&isec->lock);
6500 }
6501 
6502 /*
6503  *	called with inode->i_mutex locked
6504  */
selinux_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)6505 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
6506 {
6507 	int rc = selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX,
6508 					   ctx, ctxlen, 0);
6509 	/* Do not return error when suppressing label (SBLABEL_MNT not set). */
6510 	return rc == -EOPNOTSUPP ? 0 : rc;
6511 }
6512 
6513 /*
6514  *	called with inode->i_mutex locked
6515  */
selinux_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)6516 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
6517 {
6518 	return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SELINUX,
6519 				     ctx, ctxlen, 0);
6520 }
6521 
selinux_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)6522 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
6523 {
6524 	int len = 0;
6525 	len = selinux_inode_getsecurity(&nop_mnt_idmap, inode,
6526 					XATTR_SELINUX_SUFFIX, ctx, true);
6527 	if (len < 0)
6528 		return len;
6529 	*ctxlen = len;
6530 	return 0;
6531 }
6532 #ifdef CONFIG_KEYS
6533 
selinux_key_alloc(struct key * k,const struct cred * cred,unsigned long flags)6534 static int selinux_key_alloc(struct key *k, const struct cred *cred,
6535 			     unsigned long flags)
6536 {
6537 	const struct task_security_struct *tsec;
6538 	struct key_security_struct *ksec;
6539 
6540 	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
6541 	if (!ksec)
6542 		return -ENOMEM;
6543 
6544 	tsec = selinux_cred(cred);
6545 	if (tsec->keycreate_sid)
6546 		ksec->sid = tsec->keycreate_sid;
6547 	else
6548 		ksec->sid = tsec->sid;
6549 
6550 	k->security = ksec;
6551 	return 0;
6552 }
6553 
selinux_key_free(struct key * k)6554 static void selinux_key_free(struct key *k)
6555 {
6556 	struct key_security_struct *ksec = k->security;
6557 
6558 	k->security = NULL;
6559 	kfree(ksec);
6560 }
6561 
selinux_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)6562 static int selinux_key_permission(key_ref_t key_ref,
6563 				  const struct cred *cred,
6564 				  enum key_need_perm need_perm)
6565 {
6566 	struct key *key;
6567 	struct key_security_struct *ksec;
6568 	u32 perm, sid;
6569 
6570 	switch (need_perm) {
6571 	case KEY_NEED_VIEW:
6572 		perm = KEY__VIEW;
6573 		break;
6574 	case KEY_NEED_READ:
6575 		perm = KEY__READ;
6576 		break;
6577 	case KEY_NEED_WRITE:
6578 		perm = KEY__WRITE;
6579 		break;
6580 	case KEY_NEED_SEARCH:
6581 		perm = KEY__SEARCH;
6582 		break;
6583 	case KEY_NEED_LINK:
6584 		perm = KEY__LINK;
6585 		break;
6586 	case KEY_NEED_SETATTR:
6587 		perm = KEY__SETATTR;
6588 		break;
6589 	case KEY_NEED_UNLINK:
6590 	case KEY_SYSADMIN_OVERRIDE:
6591 	case KEY_AUTHTOKEN_OVERRIDE:
6592 	case KEY_DEFER_PERM_CHECK:
6593 		return 0;
6594 	default:
6595 		WARN_ON(1);
6596 		return -EPERM;
6597 
6598 	}
6599 
6600 	sid = cred_sid(cred);
6601 	key = key_ref_to_ptr(key_ref);
6602 	ksec = key->security;
6603 
6604 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6605 }
6606 
selinux_key_getsecurity(struct key * key,char ** _buffer)6607 static int selinux_key_getsecurity(struct key *key, char **_buffer)
6608 {
6609 	struct key_security_struct *ksec = key->security;
6610 	char *context = NULL;
6611 	unsigned len;
6612 	int rc;
6613 
6614 	rc = security_sid_to_context(ksec->sid,
6615 				     &context, &len);
6616 	if (!rc)
6617 		rc = len;
6618 	*_buffer = context;
6619 	return rc;
6620 }
6621 
6622 #ifdef CONFIG_KEY_NOTIFICATIONS
selinux_watch_key(struct key * key)6623 static int selinux_watch_key(struct key *key)
6624 {
6625 	struct key_security_struct *ksec = key->security;
6626 	u32 sid = current_sid();
6627 
6628 	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, KEY__VIEW, NULL);
6629 }
6630 #endif
6631 #endif
6632 
6633 #ifdef CONFIG_SECURITY_INFINIBAND
selinux_ib_pkey_access(void * ib_sec,u64 subnet_prefix,u16 pkey_val)6634 static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
6635 {
6636 	struct common_audit_data ad;
6637 	int err;
6638 	u32 sid = 0;
6639 	struct ib_security_struct *sec = ib_sec;
6640 	struct lsm_ibpkey_audit ibpkey;
6641 
6642 	err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6643 	if (err)
6644 		return err;
6645 
6646 	ad.type = LSM_AUDIT_DATA_IBPKEY;
6647 	ibpkey.subnet_prefix = subnet_prefix;
6648 	ibpkey.pkey = pkey_val;
6649 	ad.u.ibpkey = &ibpkey;
6650 	return avc_has_perm(sec->sid, sid,
6651 			    SECCLASS_INFINIBAND_PKEY,
6652 			    INFINIBAND_PKEY__ACCESS, &ad);
6653 }
6654 
selinux_ib_endport_manage_subnet(void * ib_sec,const char * dev_name,u8 port_num)6655 static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
6656 					    u8 port_num)
6657 {
6658 	struct common_audit_data ad;
6659 	int err;
6660 	u32 sid = 0;
6661 	struct ib_security_struct *sec = ib_sec;
6662 	struct lsm_ibendport_audit ibendport;
6663 
6664 	err = security_ib_endport_sid(dev_name, port_num,
6665 				      &sid);
6666 
6667 	if (err)
6668 		return err;
6669 
6670 	ad.type = LSM_AUDIT_DATA_IBENDPORT;
6671 	ibendport.dev_name = dev_name;
6672 	ibendport.port = port_num;
6673 	ad.u.ibendport = &ibendport;
6674 	return avc_has_perm(sec->sid, sid,
6675 			    SECCLASS_INFINIBAND_ENDPORT,
6676 			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
6677 }
6678 
selinux_ib_alloc_security(void ** ib_sec)6679 static int selinux_ib_alloc_security(void **ib_sec)
6680 {
6681 	struct ib_security_struct *sec;
6682 
6683 	sec = kzalloc(sizeof(*sec), GFP_KERNEL);
6684 	if (!sec)
6685 		return -ENOMEM;
6686 	sec->sid = current_sid();
6687 
6688 	*ib_sec = sec;
6689 	return 0;
6690 }
6691 
selinux_ib_free_security(void * ib_sec)6692 static void selinux_ib_free_security(void *ib_sec)
6693 {
6694 	kfree(ib_sec);
6695 }
6696 #endif
6697 
6698 #ifdef CONFIG_BPF_SYSCALL
selinux_bpf(int cmd,union bpf_attr * attr,unsigned int size)6699 static int selinux_bpf(int cmd, union bpf_attr *attr,
6700 				     unsigned int size)
6701 {
6702 	u32 sid = current_sid();
6703 	int ret;
6704 
6705 	switch (cmd) {
6706 	case BPF_MAP_CREATE:
6707 		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
6708 				   NULL);
6709 		break;
6710 	case BPF_PROG_LOAD:
6711 		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
6712 				   NULL);
6713 		break;
6714 	default:
6715 		ret = 0;
6716 		break;
6717 	}
6718 
6719 	return ret;
6720 }
6721 
bpf_map_fmode_to_av(fmode_t fmode)6722 static u32 bpf_map_fmode_to_av(fmode_t fmode)
6723 {
6724 	u32 av = 0;
6725 
6726 	if (fmode & FMODE_READ)
6727 		av |= BPF__MAP_READ;
6728 	if (fmode & FMODE_WRITE)
6729 		av |= BPF__MAP_WRITE;
6730 	return av;
6731 }
6732 
6733 /* This function will check the file pass through unix socket or binder to see
6734  * if it is a bpf related object. And apply corresponding checks on the bpf
6735  * object based on the type. The bpf maps and programs, not like other files and
6736  * socket, are using a shared anonymous inode inside the kernel as their inode.
6737  * So checking that inode cannot identify if the process have privilege to
6738  * access the bpf object and that's why we have to add this additional check in
6739  * selinux_file_receive and selinux_binder_transfer_files.
6740  */
bpf_fd_pass(const struct file * file,u32 sid)6741 static int bpf_fd_pass(const struct file *file, u32 sid)
6742 {
6743 	struct bpf_security_struct *bpfsec;
6744 	struct bpf_prog *prog;
6745 	struct bpf_map *map;
6746 	int ret;
6747 
6748 	if (file->f_op == &bpf_map_fops) {
6749 		map = file->private_data;
6750 		bpfsec = map->security;
6751 		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6752 				   bpf_map_fmode_to_av(file->f_mode), NULL);
6753 		if (ret)
6754 			return ret;
6755 	} else if (file->f_op == &bpf_prog_fops) {
6756 		prog = file->private_data;
6757 		bpfsec = prog->aux->security;
6758 		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6759 				   BPF__PROG_RUN, NULL);
6760 		if (ret)
6761 			return ret;
6762 	}
6763 	return 0;
6764 }
6765 
selinux_bpf_map(struct bpf_map * map,fmode_t fmode)6766 static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
6767 {
6768 	u32 sid = current_sid();
6769 	struct bpf_security_struct *bpfsec;
6770 
6771 	bpfsec = map->security;
6772 	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6773 			    bpf_map_fmode_to_av(fmode), NULL);
6774 }
6775 
selinux_bpf_prog(struct bpf_prog * prog)6776 static int selinux_bpf_prog(struct bpf_prog *prog)
6777 {
6778 	u32 sid = current_sid();
6779 	struct bpf_security_struct *bpfsec;
6780 
6781 	bpfsec = prog->aux->security;
6782 	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
6783 			    BPF__PROG_RUN, NULL);
6784 }
6785 
selinux_bpf_map_alloc(struct bpf_map * map)6786 static int selinux_bpf_map_alloc(struct bpf_map *map)
6787 {
6788 	struct bpf_security_struct *bpfsec;
6789 
6790 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6791 	if (!bpfsec)
6792 		return -ENOMEM;
6793 
6794 	bpfsec->sid = current_sid();
6795 	map->security = bpfsec;
6796 
6797 	return 0;
6798 }
6799 
selinux_bpf_map_free(struct bpf_map * map)6800 static void selinux_bpf_map_free(struct bpf_map *map)
6801 {
6802 	struct bpf_security_struct *bpfsec = map->security;
6803 
6804 	map->security = NULL;
6805 	kfree(bpfsec);
6806 }
6807 
selinux_bpf_prog_alloc(struct bpf_prog_aux * aux)6808 static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
6809 {
6810 	struct bpf_security_struct *bpfsec;
6811 
6812 	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
6813 	if (!bpfsec)
6814 		return -ENOMEM;
6815 
6816 	bpfsec->sid = current_sid();
6817 	aux->security = bpfsec;
6818 
6819 	return 0;
6820 }
6821 
selinux_bpf_prog_free(struct bpf_prog_aux * aux)6822 static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
6823 {
6824 	struct bpf_security_struct *bpfsec = aux->security;
6825 
6826 	aux->security = NULL;
6827 	kfree(bpfsec);
6828 }
6829 #endif
6830 
6831 struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
6832 	.lbs_cred = sizeof(struct task_security_struct),
6833 	.lbs_file = sizeof(struct file_security_struct),
6834 	.lbs_inode = sizeof(struct inode_security_struct),
6835 	.lbs_ipc = sizeof(struct ipc_security_struct),
6836 	.lbs_msg_msg = sizeof(struct msg_security_struct),
6837 	.lbs_superblock = sizeof(struct superblock_security_struct),
6838 	.lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
6839 };
6840 
6841 #ifdef CONFIG_PERF_EVENTS
selinux_perf_event_open(struct perf_event_attr * attr,int type)6842 static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
6843 {
6844 	u32 requested, sid = current_sid();
6845 
6846 	if (type == PERF_SECURITY_OPEN)
6847 		requested = PERF_EVENT__OPEN;
6848 	else if (type == PERF_SECURITY_CPU)
6849 		requested = PERF_EVENT__CPU;
6850 	else if (type == PERF_SECURITY_KERNEL)
6851 		requested = PERF_EVENT__KERNEL;
6852 	else if (type == PERF_SECURITY_TRACEPOINT)
6853 		requested = PERF_EVENT__TRACEPOINT;
6854 	else
6855 		return -EINVAL;
6856 
6857 	return avc_has_perm(sid, sid, SECCLASS_PERF_EVENT,
6858 			    requested, NULL);
6859 }
6860 
selinux_perf_event_alloc(struct perf_event * event)6861 static int selinux_perf_event_alloc(struct perf_event *event)
6862 {
6863 	struct perf_event_security_struct *perfsec;
6864 
6865 	perfsec = kzalloc(sizeof(*perfsec), GFP_KERNEL);
6866 	if (!perfsec)
6867 		return -ENOMEM;
6868 
6869 	perfsec->sid = current_sid();
6870 	event->security = perfsec;
6871 
6872 	return 0;
6873 }
6874 
selinux_perf_event_free(struct perf_event * event)6875 static void selinux_perf_event_free(struct perf_event *event)
6876 {
6877 	struct perf_event_security_struct *perfsec = event->security;
6878 
6879 	event->security = NULL;
6880 	kfree(perfsec);
6881 }
6882 
selinux_perf_event_read(struct perf_event * event)6883 static int selinux_perf_event_read(struct perf_event *event)
6884 {
6885 	struct perf_event_security_struct *perfsec = event->security;
6886 	u32 sid = current_sid();
6887 
6888 	return avc_has_perm(sid, perfsec->sid,
6889 			    SECCLASS_PERF_EVENT, PERF_EVENT__READ, NULL);
6890 }
6891 
selinux_perf_event_write(struct perf_event * event)6892 static int selinux_perf_event_write(struct perf_event *event)
6893 {
6894 	struct perf_event_security_struct *perfsec = event->security;
6895 	u32 sid = current_sid();
6896 
6897 	return avc_has_perm(sid, perfsec->sid,
6898 			    SECCLASS_PERF_EVENT, PERF_EVENT__WRITE, NULL);
6899 }
6900 #endif
6901 
6902 #ifdef CONFIG_IO_URING
6903 /**
6904  * selinux_uring_override_creds - check the requested cred override
6905  * @new: the target creds
6906  *
6907  * Check to see if the current task is allowed to override it's credentials
6908  * to service an io_uring operation.
6909  */
selinux_uring_override_creds(const struct cred * new)6910 static int selinux_uring_override_creds(const struct cred *new)
6911 {
6912 	return avc_has_perm(current_sid(), cred_sid(new),
6913 			    SECCLASS_IO_URING, IO_URING__OVERRIDE_CREDS, NULL);
6914 }
6915 
6916 /**
6917  * selinux_uring_sqpoll - check if a io_uring polling thread can be created
6918  *
6919  * Check to see if the current task is allowed to create a new io_uring
6920  * kernel polling thread.
6921  */
selinux_uring_sqpoll(void)6922 static int selinux_uring_sqpoll(void)
6923 {
6924 	u32 sid = current_sid();
6925 
6926 	return avc_has_perm(sid, sid,
6927 			    SECCLASS_IO_URING, IO_URING__SQPOLL, NULL);
6928 }
6929 
6930 /**
6931  * selinux_uring_cmd - check if IORING_OP_URING_CMD is allowed
6932  * @ioucmd: the io_uring command structure
6933  *
6934  * Check to see if the current domain is allowed to execute an
6935  * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
6936  *
6937  */
selinux_uring_cmd(struct io_uring_cmd * ioucmd)6938 static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
6939 {
6940 	struct file *file = ioucmd->file;
6941 	struct inode *inode = file_inode(file);
6942 	struct inode_security_struct *isec = selinux_inode(inode);
6943 	struct common_audit_data ad;
6944 
6945 	ad.type = LSM_AUDIT_DATA_FILE;
6946 	ad.u.file = file;
6947 
6948 	return avc_has_perm(current_sid(), isec->sid,
6949 			    SECCLASS_IO_URING, IO_URING__CMD, &ad);
6950 }
6951 #endif /* CONFIG_IO_URING */
6952 
6953 /*
6954  * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
6955  * 1. any hooks that don't belong to (2.) or (3.) below,
6956  * 2. hooks that both access structures allocated by other hooks, and allocate
6957  *    structures that can be later accessed by other hooks (mostly "cloning"
6958  *    hooks),
6959  * 3. hooks that only allocate structures that can be later accessed by other
6960  *    hooks ("allocating" hooks).
6961  *
6962  * Please follow block comment delimiters in the list to keep this order.
6963  */
6964 static struct security_hook_list selinux_hooks[] __ro_after_init = {
6965 	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
6966 	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
6967 	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
6968 	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),
6969 
6970 	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
6971 	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
6972 	LSM_HOOK_INIT(capget, selinux_capget),
6973 	LSM_HOOK_INIT(capset, selinux_capset),
6974 	LSM_HOOK_INIT(capable, selinux_capable),
6975 	LSM_HOOK_INIT(quotactl, selinux_quotactl),
6976 	LSM_HOOK_INIT(quota_on, selinux_quota_on),
6977 	LSM_HOOK_INIT(syslog, selinux_syslog),
6978 	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),
6979 
6980 	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),
6981 
6982 	LSM_HOOK_INIT(bprm_creds_for_exec, selinux_bprm_creds_for_exec),
6983 	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
6984 	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
6985 
6986 	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
6987 	LSM_HOOK_INIT(sb_mnt_opts_compat, selinux_sb_mnt_opts_compat),
6988 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
6989 	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
6990 	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
6991 	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
6992 	LSM_HOOK_INIT(sb_mount, selinux_mount),
6993 	LSM_HOOK_INIT(sb_umount, selinux_umount),
6994 	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
6995 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
6996 
6997 	LSM_HOOK_INIT(move_mount, selinux_move_mount),
6998 
6999 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
7000 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
7001 
7002 	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
7003 	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
7004 	LSM_HOOK_INIT(inode_init_security_anon, selinux_inode_init_security_anon),
7005 	LSM_HOOK_INIT(inode_create, selinux_inode_create),
7006 	LSM_HOOK_INIT(inode_link, selinux_inode_link),
7007 	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
7008 	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
7009 	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
7010 	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
7011 	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
7012 	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
7013 	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
7014 	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
7015 	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
7016 	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
7017 	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
7018 	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
7019 	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
7020 	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
7021 	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
7022 	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
7023 	LSM_HOOK_INIT(inode_set_acl, selinux_inode_set_acl),
7024 	LSM_HOOK_INIT(inode_get_acl, selinux_inode_get_acl),
7025 	LSM_HOOK_INIT(inode_remove_acl, selinux_inode_remove_acl),
7026 	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
7027 	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
7028 	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
7029 	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
7030 	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
7031 	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
7032 	LSM_HOOK_INIT(path_notify, selinux_path_notify),
7033 
7034 	LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security),
7035 
7036 	LSM_HOOK_INIT(file_permission, selinux_file_permission),
7037 	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
7038 	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
7039 	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
7040 	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
7041 	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
7042 	LSM_HOOK_INIT(file_lock, selinux_file_lock),
7043 	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
7044 	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
7045 	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
7046 	LSM_HOOK_INIT(file_receive, selinux_file_receive),
7047 
7048 	LSM_HOOK_INIT(file_open, selinux_file_open),
7049 
7050 	LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
7051 	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
7052 	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
7053 	LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid),
7054 	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
7055 	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
7056 	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
7057 	LSM_HOOK_INIT(kernel_load_data, selinux_kernel_load_data),
7058 	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
7059 	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
7060 	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
7061 	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
7062 	LSM_HOOK_INIT(current_getsecid_subj, selinux_current_getsecid_subj),
7063 	LSM_HOOK_INIT(task_getsecid_obj, selinux_task_getsecid_obj),
7064 	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
7065 	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
7066 	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
7067 	LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
7068 	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
7069 	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
7070 	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
7071 	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
7072 	LSM_HOOK_INIT(task_kill, selinux_task_kill),
7073 	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),
7074 	LSM_HOOK_INIT(userns_create, selinux_userns_create),
7075 
7076 	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
7077 	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
7078 
7079 	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
7080 	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
7081 	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
7082 	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),
7083 
7084 	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
7085 	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
7086 	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),
7087 
7088 	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
7089 	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
7090 	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),
7091 
7092 	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),
7093 
7094 	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
7095 	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),
7096 
7097 	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
7098 	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
7099 	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
7100 	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
7101 	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
7102 	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
7103 
7104 	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
7105 	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),
7106 
7107 	LSM_HOOK_INIT(socket_create, selinux_socket_create),
7108 	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
7109 	LSM_HOOK_INIT(socket_socketpair, selinux_socket_socketpair),
7110 	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
7111 	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
7112 	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
7113 	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
7114 	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
7115 	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
7116 	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
7117 	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
7118 	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
7119 	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
7120 	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
7121 	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
7122 	LSM_HOOK_INIT(socket_getpeersec_stream,
7123 			selinux_socket_getpeersec_stream),
7124 	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
7125 	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
7126 	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
7127 	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
7128 	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
7129 	LSM_HOOK_INIT(sctp_assoc_request, selinux_sctp_assoc_request),
7130 	LSM_HOOK_INIT(sctp_sk_clone, selinux_sctp_sk_clone),
7131 	LSM_HOOK_INIT(sctp_bind_connect, selinux_sctp_bind_connect),
7132 	LSM_HOOK_INIT(sctp_assoc_established, selinux_sctp_assoc_established),
7133 	LSM_HOOK_INIT(mptcp_add_subflow, selinux_mptcp_add_subflow),
7134 	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
7135 	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
7136 	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
7137 	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
7138 	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
7139 	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
7140 	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
7141 	LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
7142 	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
7143 	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
7144 	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
7145 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
7146 #ifdef CONFIG_SECURITY_INFINIBAND
7147 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
7148 	LSM_HOOK_INIT(ib_endport_manage_subnet,
7149 		      selinux_ib_endport_manage_subnet),
7150 	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
7151 #endif
7152 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7153 	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
7154 	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
7155 	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
7156 	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
7157 	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
7158 	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
7159 			selinux_xfrm_state_pol_flow_match),
7160 	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
7161 #endif
7162 
7163 #ifdef CONFIG_KEYS
7164 	LSM_HOOK_INIT(key_free, selinux_key_free),
7165 	LSM_HOOK_INIT(key_permission, selinux_key_permission),
7166 	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
7167 #ifdef CONFIG_KEY_NOTIFICATIONS
7168 	LSM_HOOK_INIT(watch_key, selinux_watch_key),
7169 #endif
7170 #endif
7171 
7172 #ifdef CONFIG_AUDIT
7173 	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
7174 	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
7175 	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
7176 #endif
7177 
7178 #ifdef CONFIG_BPF_SYSCALL
7179 	LSM_HOOK_INIT(bpf, selinux_bpf),
7180 	LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
7181 	LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
7182 	LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
7183 	LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
7184 #endif
7185 
7186 #ifdef CONFIG_PERF_EVENTS
7187 	LSM_HOOK_INIT(perf_event_open, selinux_perf_event_open),
7188 	LSM_HOOK_INIT(perf_event_free, selinux_perf_event_free),
7189 	LSM_HOOK_INIT(perf_event_read, selinux_perf_event_read),
7190 	LSM_HOOK_INIT(perf_event_write, selinux_perf_event_write),
7191 #endif
7192 
7193 #ifdef CONFIG_IO_URING
7194 	LSM_HOOK_INIT(uring_override_creds, selinux_uring_override_creds),
7195 	LSM_HOOK_INIT(uring_sqpoll, selinux_uring_sqpoll),
7196 	LSM_HOOK_INIT(uring_cmd, selinux_uring_cmd),
7197 #endif
7198 
7199 	/*
7200 	 * PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
7201 	 */
7202 	LSM_HOOK_INIT(fs_context_submount, selinux_fs_context_submount),
7203 	LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
7204 	LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
7205 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
7206 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7207 	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
7208 #endif
7209 
7210 	/*
7211 	 * PUT "ALLOCATING" HOOKS HERE
7212 	 */
7213 	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
7214 	LSM_HOOK_INIT(msg_queue_alloc_security,
7215 		      selinux_msg_queue_alloc_security),
7216 	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
7217 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
7218 	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
7219 	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
7220 	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
7221 	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),
7222 	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
7223 	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
7224 #ifdef CONFIG_SECURITY_INFINIBAND
7225 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
7226 #endif
7227 #ifdef CONFIG_SECURITY_NETWORK_XFRM
7228 	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
7229 	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
7230 	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
7231 		      selinux_xfrm_state_alloc_acquire),
7232 #endif
7233 #ifdef CONFIG_KEYS
7234 	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
7235 #endif
7236 #ifdef CONFIG_AUDIT
7237 	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
7238 #endif
7239 #ifdef CONFIG_BPF_SYSCALL
7240 	LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
7241 	LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
7242 #endif
7243 #ifdef CONFIG_PERF_EVENTS
7244 	LSM_HOOK_INIT(perf_event_alloc, selinux_perf_event_alloc),
7245 #endif
7246 };
7247 
selinux_init(void)7248 static __init int selinux_init(void)
7249 {
7250 	pr_info("SELinux:  Initializing.\n");
7251 
7252 	memset(&selinux_state, 0, sizeof(selinux_state));
7253 	enforcing_set(selinux_enforcing_boot);
7254 	selinux_avc_init();
7255 	mutex_init(&selinux_state.status_lock);
7256 	mutex_init(&selinux_state.policy_mutex);
7257 
7258 	/* Set the security state for the initial task. */
7259 	cred_init_security();
7260 
7261 	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
7262 	if (!default_noexec)
7263 		pr_notice("SELinux:  virtual memory is executable by default\n");
7264 
7265 	avc_init();
7266 
7267 	avtab_cache_init();
7268 
7269 	ebitmap_cache_init();
7270 
7271 	hashtab_cache_init();
7272 
7273 	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
7274 
7275 	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
7276 		panic("SELinux: Unable to register AVC netcache callback\n");
7277 
7278 	if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
7279 		panic("SELinux: Unable to register AVC LSM notifier callback\n");
7280 
7281 	if (selinux_enforcing_boot)
7282 		pr_debug("SELinux:  Starting in enforcing mode\n");
7283 	else
7284 		pr_debug("SELinux:  Starting in permissive mode\n");
7285 
7286 	fs_validate_description("selinux", selinux_fs_parameters);
7287 
7288 	return 0;
7289 }
7290 
delayed_superblock_init(struct super_block * sb,void * unused)7291 static void delayed_superblock_init(struct super_block *sb, void *unused)
7292 {
7293 	selinux_set_mnt_opts(sb, NULL, 0, NULL);
7294 }
7295 
selinux_complete_init(void)7296 void selinux_complete_init(void)
7297 {
7298 	pr_debug("SELinux:  Completing initialization.\n");
7299 
7300 	/* Set up any superblocks initialized prior to the policy load. */
7301 	pr_debug("SELinux:  Setting up existing superblocks.\n");
7302 	iterate_supers(delayed_superblock_init, NULL);
7303 }
7304 
7305 /* SELinux requires early initialization in order to label
7306    all processes and objects when they are created. */
7307 DEFINE_LSM(selinux) = {
7308 	.name = "selinux",
7309 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
7310 	.enabled = &selinux_enabled_boot,
7311 	.blobs = &selinux_blob_sizes,
7312 	.init = selinux_init,
7313 };
7314 
7315 #if defined(CONFIG_NETFILTER)
7316 static const struct nf_hook_ops selinux_nf_ops[] = {
7317 	{
7318 		.hook =		selinux_ip_postroute,
7319 		.pf =		NFPROTO_IPV4,
7320 		.hooknum =	NF_INET_POST_ROUTING,
7321 		.priority =	NF_IP_PRI_SELINUX_LAST,
7322 	},
7323 	{
7324 		.hook =		selinux_ip_forward,
7325 		.pf =		NFPROTO_IPV4,
7326 		.hooknum =	NF_INET_FORWARD,
7327 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7328 	},
7329 	{
7330 		.hook =		selinux_ip_output,
7331 		.pf =		NFPROTO_IPV4,
7332 		.hooknum =	NF_INET_LOCAL_OUT,
7333 		.priority =	NF_IP_PRI_SELINUX_FIRST,
7334 	},
7335 #if IS_ENABLED(CONFIG_IPV6)
7336 	{
7337 		.hook =		selinux_ip_postroute,
7338 		.pf =		NFPROTO_IPV6,
7339 		.hooknum =	NF_INET_POST_ROUTING,
7340 		.priority =	NF_IP6_PRI_SELINUX_LAST,
7341 	},
7342 	{
7343 		.hook =		selinux_ip_forward,
7344 		.pf =		NFPROTO_IPV6,
7345 		.hooknum =	NF_INET_FORWARD,
7346 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7347 	},
7348 	{
7349 		.hook =		selinux_ip_output,
7350 		.pf =		NFPROTO_IPV6,
7351 		.hooknum =	NF_INET_LOCAL_OUT,
7352 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
7353 	},
7354 #endif	/* IPV6 */
7355 };
7356 
selinux_nf_register(struct net * net)7357 static int __net_init selinux_nf_register(struct net *net)
7358 {
7359 	return nf_register_net_hooks(net, selinux_nf_ops,
7360 				     ARRAY_SIZE(selinux_nf_ops));
7361 }
7362 
selinux_nf_unregister(struct net * net)7363 static void __net_exit selinux_nf_unregister(struct net *net)
7364 {
7365 	nf_unregister_net_hooks(net, selinux_nf_ops,
7366 				ARRAY_SIZE(selinux_nf_ops));
7367 }
7368 
7369 static struct pernet_operations selinux_net_ops = {
7370 	.init = selinux_nf_register,
7371 	.exit = selinux_nf_unregister,
7372 };
7373 
selinux_nf_ip_init(void)7374 static int __init selinux_nf_ip_init(void)
7375 {
7376 	int err;
7377 
7378 	if (!selinux_enabled_boot)
7379 		return 0;
7380 
7381 	pr_debug("SELinux:  Registering netfilter hooks\n");
7382 
7383 	err = register_pernet_subsys(&selinux_net_ops);
7384 	if (err)
7385 		panic("SELinux: register_pernet_subsys: error %d\n", err);
7386 
7387 	return 0;
7388 }
7389 __initcall(selinux_nf_ip_init);
7390 #endif /* CONFIG_NETFILTER */
7391