1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Simplified MAC Kernel (smack) security module
4 *
5 * This file contains the smack hook function implementations.
6 *
7 * Authors:
8 * Casey Schaufler <casey@schaufler-ca.com>
9 * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
10 *
11 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
12 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
13 * Paul Moore <paul@paul-moore.com>
14 * Copyright (C) 2010 Nokia Corporation
15 * Copyright (C) 2011 Intel Corporation.
16 */
17
18 #include <linux/xattr.h>
19 #include <linux/pagemap.h>
20 #include <linux/mount.h>
21 #include <linux/stat.h>
22 #include <linux/kd.h>
23 #include <asm/ioctls.h>
24 #include <linux/ip.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/dccp.h>
28 #include <linux/icmpv6.h>
29 #include <linux/slab.h>
30 #include <linux/mutex.h>
31 #include <net/cipso_ipv4.h>
32 #include <net/ip.h>
33 #include <net/ipv6.h>
34 #include <linux/audit.h>
35 #include <linux/magic.h>
36 #include <linux/dcache.h>
37 #include <linux/personality.h>
38 #include <linux/msg.h>
39 #include <linux/shm.h>
40 #include <linux/binfmts.h>
41 #include <linux/parser.h>
42 #include <linux/fs_context.h>
43 #include <linux/fs_parser.h>
44 #include <linux/watch_queue.h>
45 #include "smack.h"
46
47 #define TRANS_TRUE "TRUE"
48 #define TRANS_TRUE_SIZE 4
49
50 #define SMK_CONNECTING 0
51 #define SMK_RECEIVING 1
52 #define SMK_SENDING 2
53
54 static DEFINE_MUTEX(smack_ipv6_lock);
55 static LIST_HEAD(smk_ipv6_port_list);
56 struct kmem_cache *smack_rule_cache;
57 int smack_enabled __initdata;
58
59 #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
60 static struct {
61 const char *name;
62 int len;
63 int opt;
64 } smk_mount_opts[] = {
65 {"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
66 A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
67 };
68 #undef A
69
match_opt_prefix(char * s,int l,char ** arg)70 static int match_opt_prefix(char *s, int l, char **arg)
71 {
72 int i;
73
74 for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
75 size_t len = smk_mount_opts[i].len;
76 if (len > l || memcmp(s, smk_mount_opts[i].name, len))
77 continue;
78 if (len == l || s[len] != '=')
79 continue;
80 *arg = s + len + 1;
81 return smk_mount_opts[i].opt;
82 }
83 return Opt_error;
84 }
85
86 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
87 static char *smk_bu_mess[] = {
88 "Bringup Error", /* Unused */
89 "Bringup", /* SMACK_BRINGUP_ALLOW */
90 "Unconfined Subject", /* SMACK_UNCONFINED_SUBJECT */
91 "Unconfined Object", /* SMACK_UNCONFINED_OBJECT */
92 };
93
smk_bu_mode(int mode,char * s)94 static void smk_bu_mode(int mode, char *s)
95 {
96 int i = 0;
97
98 if (mode & MAY_READ)
99 s[i++] = 'r';
100 if (mode & MAY_WRITE)
101 s[i++] = 'w';
102 if (mode & MAY_EXEC)
103 s[i++] = 'x';
104 if (mode & MAY_APPEND)
105 s[i++] = 'a';
106 if (mode & MAY_TRANSMUTE)
107 s[i++] = 't';
108 if (mode & MAY_LOCK)
109 s[i++] = 'l';
110 if (i == 0)
111 s[i++] = '-';
112 s[i] = '\0';
113 }
114 #endif
115
116 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_note(char * note,struct smack_known * sskp,struct smack_known * oskp,int mode,int rc)117 static int smk_bu_note(char *note, struct smack_known *sskp,
118 struct smack_known *oskp, int mode, int rc)
119 {
120 char acc[SMK_NUM_ACCESS_TYPE + 1];
121
122 if (rc <= 0)
123 return rc;
124 if (rc > SMACK_UNCONFINED_OBJECT)
125 rc = 0;
126
127 smk_bu_mode(mode, acc);
128 pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
129 sskp->smk_known, oskp->smk_known, acc, note);
130 return 0;
131 }
132 #else
133 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
134 #endif
135
136 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_current(char * note,struct smack_known * oskp,int mode,int rc)137 static int smk_bu_current(char *note, struct smack_known *oskp,
138 int mode, int rc)
139 {
140 struct task_smack *tsp = smack_cred(current_cred());
141 char acc[SMK_NUM_ACCESS_TYPE + 1];
142
143 if (rc <= 0)
144 return rc;
145 if (rc > SMACK_UNCONFINED_OBJECT)
146 rc = 0;
147
148 smk_bu_mode(mode, acc);
149 pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
150 tsp->smk_task->smk_known, oskp->smk_known,
151 acc, current->comm, note);
152 return 0;
153 }
154 #else
155 #define smk_bu_current(note, oskp, mode, RC) (RC)
156 #endif
157
158 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_task(struct task_struct * otp,int mode,int rc)159 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
160 {
161 struct task_smack *tsp = smack_cred(current_cred());
162 struct smack_known *smk_task = smk_of_task_struct_obj(otp);
163 char acc[SMK_NUM_ACCESS_TYPE + 1];
164
165 if (rc <= 0)
166 return rc;
167 if (rc > SMACK_UNCONFINED_OBJECT)
168 rc = 0;
169
170 smk_bu_mode(mode, acc);
171 pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
172 tsp->smk_task->smk_known, smk_task->smk_known, acc,
173 current->comm, otp->comm);
174 return 0;
175 }
176 #else
177 #define smk_bu_task(otp, mode, RC) (RC)
178 #endif
179
180 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_inode(struct inode * inode,int mode,int rc)181 static int smk_bu_inode(struct inode *inode, int mode, int rc)
182 {
183 struct task_smack *tsp = smack_cred(current_cred());
184 struct inode_smack *isp = smack_inode(inode);
185 char acc[SMK_NUM_ACCESS_TYPE + 1];
186
187 if (isp->smk_flags & SMK_INODE_IMPURE)
188 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
189 inode->i_sb->s_id, inode->i_ino, current->comm);
190
191 if (rc <= 0)
192 return rc;
193 if (rc > SMACK_UNCONFINED_OBJECT)
194 rc = 0;
195 if (rc == SMACK_UNCONFINED_SUBJECT &&
196 (mode & (MAY_WRITE | MAY_APPEND)))
197 isp->smk_flags |= SMK_INODE_IMPURE;
198
199 smk_bu_mode(mode, acc);
200
201 pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
202 tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
203 inode->i_sb->s_id, inode->i_ino, current->comm);
204 return 0;
205 }
206 #else
207 #define smk_bu_inode(inode, mode, RC) (RC)
208 #endif
209
210 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_file(struct file * file,int mode,int rc)211 static int smk_bu_file(struct file *file, int mode, int rc)
212 {
213 struct task_smack *tsp = smack_cred(current_cred());
214 struct smack_known *sskp = tsp->smk_task;
215 struct inode *inode = file_inode(file);
216 struct inode_smack *isp = smack_inode(inode);
217 char acc[SMK_NUM_ACCESS_TYPE + 1];
218
219 if (isp->smk_flags & SMK_INODE_IMPURE)
220 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
221 inode->i_sb->s_id, inode->i_ino, current->comm);
222
223 if (rc <= 0)
224 return rc;
225 if (rc > SMACK_UNCONFINED_OBJECT)
226 rc = 0;
227
228 smk_bu_mode(mode, acc);
229 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
230 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
231 inode->i_sb->s_id, inode->i_ino, file,
232 current->comm);
233 return 0;
234 }
235 #else
236 #define smk_bu_file(file, mode, RC) (RC)
237 #endif
238
239 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
smk_bu_credfile(const struct cred * cred,struct file * file,int mode,int rc)240 static int smk_bu_credfile(const struct cred *cred, struct file *file,
241 int mode, int rc)
242 {
243 struct task_smack *tsp = smack_cred(cred);
244 struct smack_known *sskp = tsp->smk_task;
245 struct inode *inode = file_inode(file);
246 struct inode_smack *isp = smack_inode(inode);
247 char acc[SMK_NUM_ACCESS_TYPE + 1];
248
249 if (isp->smk_flags & SMK_INODE_IMPURE)
250 pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
251 inode->i_sb->s_id, inode->i_ino, current->comm);
252
253 if (rc <= 0)
254 return rc;
255 if (rc > SMACK_UNCONFINED_OBJECT)
256 rc = 0;
257
258 smk_bu_mode(mode, acc);
259 pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
260 sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
261 inode->i_sb->s_id, inode->i_ino, file,
262 current->comm);
263 return 0;
264 }
265 #else
266 #define smk_bu_credfile(cred, file, mode, RC) (RC)
267 #endif
268
269 /**
270 * smk_fetch - Fetch the smack label from a file.
271 * @name: type of the label (attribute)
272 * @ip: a pointer to the inode
273 * @dp: a pointer to the dentry
274 *
275 * Returns a pointer to the master list entry for the Smack label,
276 * NULL if there was no label to fetch, or an error code.
277 */
smk_fetch(const char * name,struct inode * ip,struct dentry * dp)278 static struct smack_known *smk_fetch(const char *name, struct inode *ip,
279 struct dentry *dp)
280 {
281 int rc;
282 char *buffer;
283 struct smack_known *skp = NULL;
284
285 if (!(ip->i_opflags & IOP_XATTR))
286 return ERR_PTR(-EOPNOTSUPP);
287
288 buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
289 if (buffer == NULL)
290 return ERR_PTR(-ENOMEM);
291
292 rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
293 if (rc < 0)
294 skp = ERR_PTR(rc);
295 else if (rc == 0)
296 skp = NULL;
297 else
298 skp = smk_import_entry(buffer, rc);
299
300 kfree(buffer);
301
302 return skp;
303 }
304
305 /**
306 * init_inode_smack - initialize an inode security blob
307 * @inode: inode to extract the info from
308 * @skp: a pointer to the Smack label entry to use in the blob
309 *
310 */
init_inode_smack(struct inode * inode,struct smack_known * skp)311 static void init_inode_smack(struct inode *inode, struct smack_known *skp)
312 {
313 struct inode_smack *isp = smack_inode(inode);
314
315 isp->smk_inode = skp;
316 isp->smk_flags = 0;
317 }
318
319 /**
320 * init_task_smack - initialize a task security blob
321 * @tsp: blob to initialize
322 * @task: a pointer to the Smack label for the running task
323 * @forked: a pointer to the Smack label for the forked task
324 *
325 */
init_task_smack(struct task_smack * tsp,struct smack_known * task,struct smack_known * forked)326 static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
327 struct smack_known *forked)
328 {
329 tsp->smk_task = task;
330 tsp->smk_forked = forked;
331 INIT_LIST_HEAD(&tsp->smk_rules);
332 INIT_LIST_HEAD(&tsp->smk_relabel);
333 mutex_init(&tsp->smk_rules_lock);
334 }
335
336 /**
337 * smk_copy_rules - copy a rule set
338 * @nhead: new rules header pointer
339 * @ohead: old rules header pointer
340 * @gfp: type of the memory for the allocation
341 *
342 * Returns 0 on success, -ENOMEM on error
343 */
smk_copy_rules(struct list_head * nhead,struct list_head * ohead,gfp_t gfp)344 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
345 gfp_t gfp)
346 {
347 struct smack_rule *nrp;
348 struct smack_rule *orp;
349 int rc = 0;
350
351 list_for_each_entry_rcu(orp, ohead, list) {
352 nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
353 if (nrp == NULL) {
354 rc = -ENOMEM;
355 break;
356 }
357 *nrp = *orp;
358 list_add_rcu(&nrp->list, nhead);
359 }
360 return rc;
361 }
362
363 /**
364 * smk_copy_relabel - copy smk_relabel labels list
365 * @nhead: new rules header pointer
366 * @ohead: old rules header pointer
367 * @gfp: type of the memory for the allocation
368 *
369 * Returns 0 on success, -ENOMEM on error
370 */
smk_copy_relabel(struct list_head * nhead,struct list_head * ohead,gfp_t gfp)371 static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
372 gfp_t gfp)
373 {
374 struct smack_known_list_elem *nklep;
375 struct smack_known_list_elem *oklep;
376
377 list_for_each_entry(oklep, ohead, list) {
378 nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
379 if (nklep == NULL) {
380 smk_destroy_label_list(nhead);
381 return -ENOMEM;
382 }
383 nklep->smk_label = oklep->smk_label;
384 list_add(&nklep->list, nhead);
385 }
386
387 return 0;
388 }
389
390 /**
391 * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
392 * @mode - input mode in form of PTRACE_MODE_*
393 *
394 * Returns a converted MAY_* mode usable by smack rules
395 */
smk_ptrace_mode(unsigned int mode)396 static inline unsigned int smk_ptrace_mode(unsigned int mode)
397 {
398 if (mode & PTRACE_MODE_ATTACH)
399 return MAY_READWRITE;
400 if (mode & PTRACE_MODE_READ)
401 return MAY_READ;
402
403 return 0;
404 }
405
406 /**
407 * smk_ptrace_rule_check - helper for ptrace access
408 * @tracer: tracer process
409 * @tracee_known: label entry of the process that's about to be traced
410 * @mode: ptrace attachment mode (PTRACE_MODE_*)
411 * @func: name of the function that called us, used for audit
412 *
413 * Returns 0 on access granted, -error on error
414 */
smk_ptrace_rule_check(struct task_struct * tracer,struct smack_known * tracee_known,unsigned int mode,const char * func)415 static int smk_ptrace_rule_check(struct task_struct *tracer,
416 struct smack_known *tracee_known,
417 unsigned int mode, const char *func)
418 {
419 int rc;
420 struct smk_audit_info ad, *saip = NULL;
421 struct task_smack *tsp;
422 struct smack_known *tracer_known;
423 const struct cred *tracercred;
424
425 if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
426 smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
427 smk_ad_setfield_u_tsk(&ad, tracer);
428 saip = &ad;
429 }
430
431 rcu_read_lock();
432 tracercred = __task_cred(tracer);
433 tsp = smack_cred(tracercred);
434 tracer_known = smk_of_task(tsp);
435
436 if ((mode & PTRACE_MODE_ATTACH) &&
437 (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
438 smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
439 if (tracer_known->smk_known == tracee_known->smk_known)
440 rc = 0;
441 else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
442 rc = -EACCES;
443 else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
444 rc = 0;
445 else
446 rc = -EACCES;
447
448 if (saip)
449 smack_log(tracer_known->smk_known,
450 tracee_known->smk_known,
451 0, rc, saip);
452
453 rcu_read_unlock();
454 return rc;
455 }
456
457 /* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
458 rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
459
460 rcu_read_unlock();
461 return rc;
462 }
463
464 /*
465 * LSM hooks.
466 * We he, that is fun!
467 */
468
469 /**
470 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
471 * @ctp: child task pointer
472 * @mode: ptrace attachment mode (PTRACE_MODE_*)
473 *
474 * Returns 0 if access is OK, an error code otherwise
475 *
476 * Do the capability checks.
477 */
smack_ptrace_access_check(struct task_struct * ctp,unsigned int mode)478 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
479 {
480 struct smack_known *skp;
481
482 skp = smk_of_task_struct_obj(ctp);
483
484 return smk_ptrace_rule_check(current, skp, mode, __func__);
485 }
486
487 /**
488 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
489 * @ptp: parent task pointer
490 *
491 * Returns 0 if access is OK, an error code otherwise
492 *
493 * Do the capability checks, and require PTRACE_MODE_ATTACH.
494 */
smack_ptrace_traceme(struct task_struct * ptp)495 static int smack_ptrace_traceme(struct task_struct *ptp)
496 {
497 int rc;
498 struct smack_known *skp;
499
500 skp = smk_of_task(smack_cred(current_cred()));
501
502 rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
503 return rc;
504 }
505
506 /**
507 * smack_syslog - Smack approval on syslog
508 * @typefrom_file: unused
509 *
510 * Returns 0 on success, error code otherwise.
511 */
smack_syslog(int typefrom_file)512 static int smack_syslog(int typefrom_file)
513 {
514 int rc = 0;
515 struct smack_known *skp = smk_of_current();
516
517 if (smack_privileged(CAP_MAC_OVERRIDE))
518 return 0;
519
520 if (smack_syslog_label != NULL && smack_syslog_label != skp)
521 rc = -EACCES;
522
523 return rc;
524 }
525
526 /*
527 * Superblock Hooks.
528 */
529
530 /**
531 * smack_sb_alloc_security - allocate a superblock blob
532 * @sb: the superblock getting the blob
533 *
534 * Returns 0 on success or -ENOMEM on error.
535 */
smack_sb_alloc_security(struct super_block * sb)536 static int smack_sb_alloc_security(struct super_block *sb)
537 {
538 struct superblock_smack *sbsp = smack_superblock(sb);
539
540 sbsp->smk_root = &smack_known_floor;
541 sbsp->smk_default = &smack_known_floor;
542 sbsp->smk_floor = &smack_known_floor;
543 sbsp->smk_hat = &smack_known_hat;
544 /*
545 * SMK_SB_INITIALIZED will be zero from kzalloc.
546 */
547
548 return 0;
549 }
550
551 struct smack_mnt_opts {
552 const char *fsdefault, *fsfloor, *fshat, *fsroot, *fstransmute;
553 };
554
smack_free_mnt_opts(void * mnt_opts)555 static void smack_free_mnt_opts(void *mnt_opts)
556 {
557 struct smack_mnt_opts *opts = mnt_opts;
558 kfree(opts->fsdefault);
559 kfree(opts->fsfloor);
560 kfree(opts->fshat);
561 kfree(opts->fsroot);
562 kfree(opts->fstransmute);
563 kfree(opts);
564 }
565
smack_add_opt(int token,const char * s,void ** mnt_opts)566 static int smack_add_opt(int token, const char *s, void **mnt_opts)
567 {
568 struct smack_mnt_opts *opts = *mnt_opts;
569
570 if (!opts) {
571 opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
572 if (!opts)
573 return -ENOMEM;
574 *mnt_opts = opts;
575 }
576 if (!s)
577 return -ENOMEM;
578
579 switch (token) {
580 case Opt_fsdefault:
581 if (opts->fsdefault)
582 goto out_opt_err;
583 opts->fsdefault = s;
584 break;
585 case Opt_fsfloor:
586 if (opts->fsfloor)
587 goto out_opt_err;
588 opts->fsfloor = s;
589 break;
590 case Opt_fshat:
591 if (opts->fshat)
592 goto out_opt_err;
593 opts->fshat = s;
594 break;
595 case Opt_fsroot:
596 if (opts->fsroot)
597 goto out_opt_err;
598 opts->fsroot = s;
599 break;
600 case Opt_fstransmute:
601 if (opts->fstransmute)
602 goto out_opt_err;
603 opts->fstransmute = s;
604 break;
605 }
606 return 0;
607
608 out_opt_err:
609 pr_warn("Smack: duplicate mount options\n");
610 return -EINVAL;
611 }
612
613 /**
614 * smack_fs_context_dup - Duplicate the security data on fs_context duplication
615 * @fc: The new filesystem context.
616 * @src_fc: The source filesystem context being duplicated.
617 *
618 * Returns 0 on success or -ENOMEM on error.
619 */
smack_fs_context_dup(struct fs_context * fc,struct fs_context * src_fc)620 static int smack_fs_context_dup(struct fs_context *fc,
621 struct fs_context *src_fc)
622 {
623 struct smack_mnt_opts *dst, *src = src_fc->security;
624
625 if (!src)
626 return 0;
627
628 fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
629 if (!fc->security)
630 return -ENOMEM;
631 dst = fc->security;
632
633 if (src->fsdefault) {
634 dst->fsdefault = kstrdup(src->fsdefault, GFP_KERNEL);
635 if (!dst->fsdefault)
636 return -ENOMEM;
637 }
638 if (src->fsfloor) {
639 dst->fsfloor = kstrdup(src->fsfloor, GFP_KERNEL);
640 if (!dst->fsfloor)
641 return -ENOMEM;
642 }
643 if (src->fshat) {
644 dst->fshat = kstrdup(src->fshat, GFP_KERNEL);
645 if (!dst->fshat)
646 return -ENOMEM;
647 }
648 if (src->fsroot) {
649 dst->fsroot = kstrdup(src->fsroot, GFP_KERNEL);
650 if (!dst->fsroot)
651 return -ENOMEM;
652 }
653 if (src->fstransmute) {
654 dst->fstransmute = kstrdup(src->fstransmute, GFP_KERNEL);
655 if (!dst->fstransmute)
656 return -ENOMEM;
657 }
658 return 0;
659 }
660
661 static const struct fs_parameter_spec smack_fs_parameters[] = {
662 fsparam_string("smackfsdef", Opt_fsdefault),
663 fsparam_string("smackfsdefault", Opt_fsdefault),
664 fsparam_string("smackfsfloor", Opt_fsfloor),
665 fsparam_string("smackfshat", Opt_fshat),
666 fsparam_string("smackfsroot", Opt_fsroot),
667 fsparam_string("smackfstransmute", Opt_fstransmute),
668 {}
669 };
670
671 /**
672 * smack_fs_context_parse_param - Parse a single mount parameter
673 * @fc: The new filesystem context being constructed.
674 * @param: The parameter.
675 *
676 * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
677 * error.
678 */
smack_fs_context_parse_param(struct fs_context * fc,struct fs_parameter * param)679 static int smack_fs_context_parse_param(struct fs_context *fc,
680 struct fs_parameter *param)
681 {
682 struct fs_parse_result result;
683 int opt, rc;
684
685 opt = fs_parse(fc, smack_fs_parameters, param, &result);
686 if (opt < 0)
687 return opt;
688
689 rc = smack_add_opt(opt, param->string, &fc->security);
690 if (!rc)
691 param->string = NULL;
692 return rc;
693 }
694
smack_sb_eat_lsm_opts(char * options,void ** mnt_opts)695 static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
696 {
697 char *from = options, *to = options;
698 bool first = true;
699
700 while (1) {
701 char *next = strchr(from, ',');
702 int token, len, rc;
703 char *arg = NULL;
704
705 if (next)
706 len = next - from;
707 else
708 len = strlen(from);
709
710 token = match_opt_prefix(from, len, &arg);
711 if (token != Opt_error) {
712 arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
713 rc = smack_add_opt(token, arg, mnt_opts);
714 if (unlikely(rc)) {
715 kfree(arg);
716 if (*mnt_opts)
717 smack_free_mnt_opts(*mnt_opts);
718 *mnt_opts = NULL;
719 return rc;
720 }
721 } else {
722 if (!first) { // copy with preceding comma
723 from--;
724 len++;
725 }
726 if (to != from)
727 memmove(to, from, len);
728 to += len;
729 first = false;
730 }
731 if (!from[len])
732 break;
733 from += len + 1;
734 }
735 *to = '\0';
736 return 0;
737 }
738
739 /**
740 * smack_set_mnt_opts - set Smack specific mount options
741 * @sb: the file system superblock
742 * @mnt_opts: Smack mount options
743 * @kern_flags: mount option from kernel space or user space
744 * @set_kern_flags: where to store converted mount opts
745 *
746 * Returns 0 on success, an error code on failure
747 *
748 * Allow filesystems with binary mount data to explicitly set Smack mount
749 * labels.
750 */
smack_set_mnt_opts(struct super_block * sb,void * mnt_opts,unsigned long kern_flags,unsigned long * set_kern_flags)751 static int smack_set_mnt_opts(struct super_block *sb,
752 void *mnt_opts,
753 unsigned long kern_flags,
754 unsigned long *set_kern_flags)
755 {
756 struct dentry *root = sb->s_root;
757 struct inode *inode = d_backing_inode(root);
758 struct superblock_smack *sp = smack_superblock(sb);
759 struct inode_smack *isp;
760 struct smack_known *skp;
761 struct smack_mnt_opts *opts = mnt_opts;
762 bool transmute = false;
763
764 if (sp->smk_flags & SMK_SB_INITIALIZED)
765 return 0;
766
767 if (inode->i_security == NULL) {
768 int rc = lsm_inode_alloc(inode);
769
770 if (rc)
771 return rc;
772 }
773
774 if (!smack_privileged(CAP_MAC_ADMIN)) {
775 /*
776 * Unprivileged mounts don't get to specify Smack values.
777 */
778 if (opts)
779 return -EPERM;
780 /*
781 * Unprivileged mounts get root and default from the caller.
782 */
783 skp = smk_of_current();
784 sp->smk_root = skp;
785 sp->smk_default = skp;
786 /*
787 * For a handful of fs types with no user-controlled
788 * backing store it's okay to trust security labels
789 * in the filesystem. The rest are untrusted.
790 */
791 if (sb->s_user_ns != &init_user_ns &&
792 sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
793 sb->s_magic != RAMFS_MAGIC) {
794 transmute = true;
795 sp->smk_flags |= SMK_SB_UNTRUSTED;
796 }
797 }
798
799 sp->smk_flags |= SMK_SB_INITIALIZED;
800
801 if (opts) {
802 if (opts->fsdefault) {
803 skp = smk_import_entry(opts->fsdefault, 0);
804 if (IS_ERR(skp))
805 return PTR_ERR(skp);
806 sp->smk_default = skp;
807 }
808 if (opts->fsfloor) {
809 skp = smk_import_entry(opts->fsfloor, 0);
810 if (IS_ERR(skp))
811 return PTR_ERR(skp);
812 sp->smk_floor = skp;
813 }
814 if (opts->fshat) {
815 skp = smk_import_entry(opts->fshat, 0);
816 if (IS_ERR(skp))
817 return PTR_ERR(skp);
818 sp->smk_hat = skp;
819 }
820 if (opts->fsroot) {
821 skp = smk_import_entry(opts->fsroot, 0);
822 if (IS_ERR(skp))
823 return PTR_ERR(skp);
824 sp->smk_root = skp;
825 }
826 if (opts->fstransmute) {
827 skp = smk_import_entry(opts->fstransmute, 0);
828 if (IS_ERR(skp))
829 return PTR_ERR(skp);
830 sp->smk_root = skp;
831 transmute = true;
832 }
833 }
834
835 /*
836 * Initialize the root inode.
837 */
838 init_inode_smack(inode, sp->smk_root);
839
840 if (transmute) {
841 isp = smack_inode(inode);
842 isp->smk_flags |= SMK_INODE_TRANSMUTE;
843 }
844
845 return 0;
846 }
847
848 /**
849 * smack_sb_statfs - Smack check on statfs
850 * @dentry: identifies the file system in question
851 *
852 * Returns 0 if current can read the floor of the filesystem,
853 * and error code otherwise
854 */
smack_sb_statfs(struct dentry * dentry)855 static int smack_sb_statfs(struct dentry *dentry)
856 {
857 struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
858 int rc;
859 struct smk_audit_info ad;
860
861 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
862 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
863
864 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
865 rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
866 return rc;
867 }
868
869 /*
870 * BPRM hooks
871 */
872
873 /**
874 * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
875 * @bprm: the exec information
876 *
877 * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
878 */
smack_bprm_creds_for_exec(struct linux_binprm * bprm)879 static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
880 {
881 struct inode *inode = file_inode(bprm->file);
882 struct task_smack *bsp = smack_cred(bprm->cred);
883 struct inode_smack *isp;
884 struct superblock_smack *sbsp;
885 int rc;
886
887 isp = smack_inode(inode);
888 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
889 return 0;
890
891 sbsp = smack_superblock(inode->i_sb);
892 if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
893 isp->smk_task != sbsp->smk_root)
894 return 0;
895
896 if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
897 struct task_struct *tracer;
898 rc = 0;
899
900 rcu_read_lock();
901 tracer = ptrace_parent(current);
902 if (likely(tracer != NULL))
903 rc = smk_ptrace_rule_check(tracer,
904 isp->smk_task,
905 PTRACE_MODE_ATTACH,
906 __func__);
907 rcu_read_unlock();
908
909 if (rc != 0)
910 return rc;
911 }
912 if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
913 return -EPERM;
914
915 bsp->smk_task = isp->smk_task;
916 bprm->per_clear |= PER_CLEAR_ON_SETID;
917
918 /* Decide if this is a secure exec. */
919 if (bsp->smk_task != bsp->smk_forked)
920 bprm->secureexec = 1;
921
922 return 0;
923 }
924
925 /*
926 * Inode hooks
927 */
928
929 /**
930 * smack_inode_alloc_security - allocate an inode blob
931 * @inode: the inode in need of a blob
932 *
933 * Returns 0
934 */
smack_inode_alloc_security(struct inode * inode)935 static int smack_inode_alloc_security(struct inode *inode)
936 {
937 struct smack_known *skp = smk_of_current();
938
939 init_inode_smack(inode, skp);
940 return 0;
941 }
942
943 /**
944 * smack_inode_init_security - copy out the smack from an inode
945 * @inode: the newly created inode
946 * @dir: containing directory object
947 * @qstr: unused
948 * @name: where to put the attribute name
949 * @value: where to put the attribute value
950 * @len: where to put the length of the attribute
951 *
952 * Returns 0 if it all works out, -ENOMEM if there's no memory
953 */
smack_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,const char ** name,void ** value,size_t * len)954 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
955 const struct qstr *qstr, const char **name,
956 void **value, size_t *len)
957 {
958 struct inode_smack *issp = smack_inode(inode);
959 struct smack_known *skp = smk_of_current();
960 struct smack_known *isp = smk_of_inode(inode);
961 struct smack_known *dsp = smk_of_inode(dir);
962 int may;
963
964 if (name)
965 *name = XATTR_SMACK_SUFFIX;
966
967 if (value && len) {
968 rcu_read_lock();
969 may = smk_access_entry(skp->smk_known, dsp->smk_known,
970 &skp->smk_rules);
971 rcu_read_unlock();
972
973 /*
974 * If the access rule allows transmutation and
975 * the directory requests transmutation then
976 * by all means transmute.
977 * Mark the inode as changed.
978 */
979 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
980 smk_inode_transmutable(dir)) {
981 isp = dsp;
982 issp->smk_flags |= SMK_INODE_CHANGED;
983 }
984
985 *value = kstrdup(isp->smk_known, GFP_NOFS);
986 if (*value == NULL)
987 return -ENOMEM;
988
989 *len = strlen(isp->smk_known);
990 }
991
992 return 0;
993 }
994
995 /**
996 * smack_inode_link - Smack check on link
997 * @old_dentry: the existing object
998 * @dir: unused
999 * @new_dentry: the new object
1000 *
1001 * Returns 0 if access is permitted, an error code otherwise
1002 */
smack_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)1003 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
1004 struct dentry *new_dentry)
1005 {
1006 struct smack_known *isp;
1007 struct smk_audit_info ad;
1008 int rc;
1009
1010 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1011 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1012
1013 isp = smk_of_inode(d_backing_inode(old_dentry));
1014 rc = smk_curacc(isp, MAY_WRITE, &ad);
1015 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
1016
1017 if (rc == 0 && d_is_positive(new_dentry)) {
1018 isp = smk_of_inode(d_backing_inode(new_dentry));
1019 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1020 rc = smk_curacc(isp, MAY_WRITE, &ad);
1021 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1022 }
1023
1024 return rc;
1025 }
1026
1027 /**
1028 * smack_inode_unlink - Smack check on inode deletion
1029 * @dir: containing directory object
1030 * @dentry: file to unlink
1031 *
1032 * Returns 0 if current can write the containing directory
1033 * and the object, error code otherwise
1034 */
smack_inode_unlink(struct inode * dir,struct dentry * dentry)1035 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
1036 {
1037 struct inode *ip = d_backing_inode(dentry);
1038 struct smk_audit_info ad;
1039 int rc;
1040
1041 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1042 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1043
1044 /*
1045 * You need write access to the thing you're unlinking
1046 */
1047 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
1048 rc = smk_bu_inode(ip, MAY_WRITE, rc);
1049 if (rc == 0) {
1050 /*
1051 * You also need write access to the containing directory
1052 */
1053 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1054 smk_ad_setfield_u_fs_inode(&ad, dir);
1055 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1056 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1057 }
1058 return rc;
1059 }
1060
1061 /**
1062 * smack_inode_rmdir - Smack check on directory deletion
1063 * @dir: containing directory object
1064 * @dentry: directory to unlink
1065 *
1066 * Returns 0 if current can write the containing directory
1067 * and the directory, error code otherwise
1068 */
smack_inode_rmdir(struct inode * dir,struct dentry * dentry)1069 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
1070 {
1071 struct smk_audit_info ad;
1072 int rc;
1073
1074 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1075 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1076
1077 /*
1078 * You need write access to the thing you're removing
1079 */
1080 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1081 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1082 if (rc == 0) {
1083 /*
1084 * You also need write access to the containing directory
1085 */
1086 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1087 smk_ad_setfield_u_fs_inode(&ad, dir);
1088 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1089 rc = smk_bu_inode(dir, MAY_WRITE, rc);
1090 }
1091
1092 return rc;
1093 }
1094
1095 /**
1096 * smack_inode_rename - Smack check on rename
1097 * @old_inode: unused
1098 * @old_dentry: the old object
1099 * @new_inode: unused
1100 * @new_dentry: the new object
1101 *
1102 * Read and write access is required on both the old and
1103 * new directories.
1104 *
1105 * Returns 0 if access is permitted, an error code otherwise
1106 */
smack_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)1107 static int smack_inode_rename(struct inode *old_inode,
1108 struct dentry *old_dentry,
1109 struct inode *new_inode,
1110 struct dentry *new_dentry)
1111 {
1112 int rc;
1113 struct smack_known *isp;
1114 struct smk_audit_info ad;
1115
1116 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1117 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1118
1119 isp = smk_of_inode(d_backing_inode(old_dentry));
1120 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1121 rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1122
1123 if (rc == 0 && d_is_positive(new_dentry)) {
1124 isp = smk_of_inode(d_backing_inode(new_dentry));
1125 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1126 rc = smk_curacc(isp, MAY_READWRITE, &ad);
1127 rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1128 }
1129 return rc;
1130 }
1131
1132 /**
1133 * smack_inode_permission - Smack version of permission()
1134 * @inode: the inode in question
1135 * @mask: the access requested
1136 *
1137 * This is the important Smack hook.
1138 *
1139 * Returns 0 if access is permitted, an error code otherwise
1140 */
smack_inode_permission(struct inode * inode,int mask)1141 static int smack_inode_permission(struct inode *inode, int mask)
1142 {
1143 struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
1144 struct smk_audit_info ad;
1145 int no_block = mask & MAY_NOT_BLOCK;
1146 int rc;
1147
1148 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1149 /*
1150 * No permission to check. Existence test. Yup, it's there.
1151 */
1152 if (mask == 0)
1153 return 0;
1154
1155 if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
1156 if (smk_of_inode(inode) != sbsp->smk_root)
1157 return -EACCES;
1158 }
1159
1160 /* May be droppable after audit */
1161 if (no_block)
1162 return -ECHILD;
1163 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1164 smk_ad_setfield_u_fs_inode(&ad, inode);
1165 rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1166 rc = smk_bu_inode(inode, mask, rc);
1167 return rc;
1168 }
1169
1170 /**
1171 * smack_inode_setattr - Smack check for setting attributes
1172 * @dentry: the object
1173 * @iattr: for the force flag
1174 *
1175 * Returns 0 if access is permitted, an error code otherwise
1176 */
smack_inode_setattr(struct dentry * dentry,struct iattr * iattr)1177 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
1178 {
1179 struct smk_audit_info ad;
1180 int rc;
1181
1182 /*
1183 * Need to allow for clearing the setuid bit.
1184 */
1185 if (iattr->ia_valid & ATTR_FORCE)
1186 return 0;
1187 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1188 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1189
1190 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1191 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1192 return rc;
1193 }
1194
1195 /**
1196 * smack_inode_getattr - Smack check for getting attributes
1197 * @path: path to extract the info from
1198 *
1199 * Returns 0 if access is permitted, an error code otherwise
1200 */
smack_inode_getattr(const struct path * path)1201 static int smack_inode_getattr(const struct path *path)
1202 {
1203 struct smk_audit_info ad;
1204 struct inode *inode = d_backing_inode(path->dentry);
1205 int rc;
1206
1207 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1208 smk_ad_setfield_u_fs_path(&ad, *path);
1209 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1210 rc = smk_bu_inode(inode, MAY_READ, rc);
1211 return rc;
1212 }
1213
1214 /**
1215 * smack_inode_setxattr - Smack check for setting xattrs
1216 * @dentry: the object
1217 * @name: name of the attribute
1218 * @value: value of the attribute
1219 * @size: size of the value
1220 * @flags: unused
1221 *
1222 * This protects the Smack attribute explicitly.
1223 *
1224 * Returns 0 if access is permitted, an error code otherwise
1225 */
smack_inode_setxattr(struct user_namespace * mnt_userns,struct dentry * dentry,const char * name,const void * value,size_t size,int flags)1226 static int smack_inode_setxattr(struct user_namespace *mnt_userns,
1227 struct dentry *dentry, const char *name,
1228 const void *value, size_t size, int flags)
1229 {
1230 struct smk_audit_info ad;
1231 struct smack_known *skp;
1232 int check_priv = 0;
1233 int check_import = 0;
1234 int check_star = 0;
1235 int rc = 0;
1236
1237 /*
1238 * Check label validity here so import won't fail in post_setxattr
1239 */
1240 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1241 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1242 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1243 check_priv = 1;
1244 check_import = 1;
1245 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1246 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1247 check_priv = 1;
1248 check_import = 1;
1249 check_star = 1;
1250 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1251 check_priv = 1;
1252 if (size != TRANS_TRUE_SIZE ||
1253 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1254 rc = -EINVAL;
1255 } else
1256 rc = cap_inode_setxattr(dentry, name, value, size, flags);
1257
1258 if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1259 rc = -EPERM;
1260
1261 if (rc == 0 && check_import) {
1262 skp = size ? smk_import_entry(value, size) : NULL;
1263 if (IS_ERR(skp))
1264 rc = PTR_ERR(skp);
1265 else if (skp == NULL || (check_star &&
1266 (skp == &smack_known_star || skp == &smack_known_web)))
1267 rc = -EINVAL;
1268 }
1269
1270 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1271 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1272
1273 if (rc == 0) {
1274 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1275 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1276 }
1277
1278 return rc;
1279 }
1280
1281 /**
1282 * smack_inode_post_setxattr - Apply the Smack update approved above
1283 * @dentry: object
1284 * @name: attribute name
1285 * @value: attribute value
1286 * @size: attribute size
1287 * @flags: unused
1288 *
1289 * Set the pointer in the inode blob to the entry found
1290 * in the master label list.
1291 */
smack_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)1292 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1293 const void *value, size_t size, int flags)
1294 {
1295 struct smack_known *skp;
1296 struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1297
1298 if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1299 isp->smk_flags |= SMK_INODE_TRANSMUTE;
1300 return;
1301 }
1302
1303 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1304 skp = smk_import_entry(value, size);
1305 if (!IS_ERR(skp))
1306 isp->smk_inode = skp;
1307 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1308 skp = smk_import_entry(value, size);
1309 if (!IS_ERR(skp))
1310 isp->smk_task = skp;
1311 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1312 skp = smk_import_entry(value, size);
1313 if (!IS_ERR(skp))
1314 isp->smk_mmap = skp;
1315 }
1316
1317 return;
1318 }
1319
1320 /**
1321 * smack_inode_getxattr - Smack check on getxattr
1322 * @dentry: the object
1323 * @name: unused
1324 *
1325 * Returns 0 if access is permitted, an error code otherwise
1326 */
smack_inode_getxattr(struct dentry * dentry,const char * name)1327 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1328 {
1329 struct smk_audit_info ad;
1330 int rc;
1331
1332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1333 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1334
1335 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1336 rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1337 return rc;
1338 }
1339
1340 /**
1341 * smack_inode_removexattr - Smack check on removexattr
1342 * @dentry: the object
1343 * @name: name of the attribute
1344 *
1345 * Removing the Smack attribute requires CAP_MAC_ADMIN
1346 *
1347 * Returns 0 if access is permitted, an error code otherwise
1348 */
smack_inode_removexattr(struct user_namespace * mnt_userns,struct dentry * dentry,const char * name)1349 static int smack_inode_removexattr(struct user_namespace *mnt_userns,
1350 struct dentry *dentry, const char *name)
1351 {
1352 struct inode_smack *isp;
1353 struct smk_audit_info ad;
1354 int rc = 0;
1355
1356 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1357 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1358 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1359 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1360 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1361 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1362 if (!smack_privileged(CAP_MAC_ADMIN))
1363 rc = -EPERM;
1364 } else
1365 rc = cap_inode_removexattr(mnt_userns, dentry, name);
1366
1367 if (rc != 0)
1368 return rc;
1369
1370 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1371 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1372
1373 rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1374 rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1375 if (rc != 0)
1376 return rc;
1377
1378 isp = smack_inode(d_backing_inode(dentry));
1379 /*
1380 * Don't do anything special for these.
1381 * XATTR_NAME_SMACKIPIN
1382 * XATTR_NAME_SMACKIPOUT
1383 */
1384 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1385 struct super_block *sbp = dentry->d_sb;
1386 struct superblock_smack *sbsp = smack_superblock(sbp);
1387
1388 isp->smk_inode = sbsp->smk_default;
1389 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1390 isp->smk_task = NULL;
1391 else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1392 isp->smk_mmap = NULL;
1393 else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1394 isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1395
1396 return 0;
1397 }
1398
1399 /**
1400 * smack_inode_getsecurity - get smack xattrs
1401 * @inode: the object
1402 * @name: attribute name
1403 * @buffer: where to put the result
1404 * @alloc: duplicate memory
1405 *
1406 * Returns the size of the attribute or an error code
1407 */
smack_inode_getsecurity(struct user_namespace * mnt_userns,struct inode * inode,const char * name,void ** buffer,bool alloc)1408 static int smack_inode_getsecurity(struct user_namespace *mnt_userns,
1409 struct inode *inode, const char *name,
1410 void **buffer, bool alloc)
1411 {
1412 struct socket_smack *ssp;
1413 struct socket *sock;
1414 struct super_block *sbp;
1415 struct inode *ip = (struct inode *)inode;
1416 struct smack_known *isp;
1417
1418 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
1419 isp = smk_of_inode(inode);
1420 else {
1421 /*
1422 * The rest of the Smack xattrs are only on sockets.
1423 */
1424 sbp = ip->i_sb;
1425 if (sbp->s_magic != SOCKFS_MAGIC)
1426 return -EOPNOTSUPP;
1427
1428 sock = SOCKET_I(ip);
1429 if (sock == NULL || sock->sk == NULL)
1430 return -EOPNOTSUPP;
1431
1432 ssp = sock->sk->sk_security;
1433
1434 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1435 isp = ssp->smk_in;
1436 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1437 isp = ssp->smk_out;
1438 else
1439 return -EOPNOTSUPP;
1440 }
1441
1442 if (alloc) {
1443 *buffer = kstrdup(isp->smk_known, GFP_KERNEL);
1444 if (*buffer == NULL)
1445 return -ENOMEM;
1446 }
1447
1448 return strlen(isp->smk_known);
1449 }
1450
1451
1452 /**
1453 * smack_inode_listsecurity - list the Smack attributes
1454 * @inode: the object
1455 * @buffer: where they go
1456 * @buffer_size: size of buffer
1457 */
smack_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)1458 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1459 size_t buffer_size)
1460 {
1461 int len = sizeof(XATTR_NAME_SMACK);
1462
1463 if (buffer != NULL && len <= buffer_size)
1464 memcpy(buffer, XATTR_NAME_SMACK, len);
1465
1466 return len;
1467 }
1468
1469 /**
1470 * smack_inode_getsecid - Extract inode's security id
1471 * @inode: inode to extract the info from
1472 * @secid: where result will be saved
1473 */
smack_inode_getsecid(struct inode * inode,u32 * secid)1474 static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1475 {
1476 struct smack_known *skp = smk_of_inode(inode);
1477
1478 *secid = skp->smk_secid;
1479 }
1480
1481 /*
1482 * File Hooks
1483 */
1484
1485 /*
1486 * There is no smack_file_permission hook
1487 *
1488 * Should access checks be done on each read or write?
1489 * UNICOS and SELinux say yes.
1490 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1491 *
1492 * I'll say no for now. Smack does not do the frequent
1493 * label changing that SELinux does.
1494 */
1495
1496 /**
1497 * smack_file_alloc_security - assign a file security blob
1498 * @file: the object
1499 *
1500 * The security blob for a file is a pointer to the master
1501 * label list, so no allocation is done.
1502 *
1503 * f_security is the owner security information. It
1504 * isn't used on file access checks, it's for send_sigio.
1505 *
1506 * Returns 0
1507 */
smack_file_alloc_security(struct file * file)1508 static int smack_file_alloc_security(struct file *file)
1509 {
1510 struct smack_known **blob = smack_file(file);
1511
1512 *blob = smk_of_current();
1513 return 0;
1514 }
1515
1516 /**
1517 * smack_file_ioctl - Smack check on ioctls
1518 * @file: the object
1519 * @cmd: what to do
1520 * @arg: unused
1521 *
1522 * Relies heavily on the correct use of the ioctl command conventions.
1523 *
1524 * Returns 0 if allowed, error code otherwise
1525 */
smack_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1526 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1527 unsigned long arg)
1528 {
1529 int rc = 0;
1530 struct smk_audit_info ad;
1531 struct inode *inode = file_inode(file);
1532
1533 if (unlikely(IS_PRIVATE(inode)))
1534 return 0;
1535
1536 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1537 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1538
1539 if (_IOC_DIR(cmd) & _IOC_WRITE) {
1540 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1541 rc = smk_bu_file(file, MAY_WRITE, rc);
1542 }
1543
1544 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1545 rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1546 rc = smk_bu_file(file, MAY_READ, rc);
1547 }
1548
1549 return rc;
1550 }
1551
1552 /**
1553 * smack_file_lock - Smack check on file locking
1554 * @file: the object
1555 * @cmd: unused
1556 *
1557 * Returns 0 if current has lock access, error code otherwise
1558 */
smack_file_lock(struct file * file,unsigned int cmd)1559 static int smack_file_lock(struct file *file, unsigned int cmd)
1560 {
1561 struct smk_audit_info ad;
1562 int rc;
1563 struct inode *inode = file_inode(file);
1564
1565 if (unlikely(IS_PRIVATE(inode)))
1566 return 0;
1567
1568 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1569 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1570 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1571 rc = smk_bu_file(file, MAY_LOCK, rc);
1572 return rc;
1573 }
1574
1575 /**
1576 * smack_file_fcntl - Smack check on fcntl
1577 * @file: the object
1578 * @cmd: what action to check
1579 * @arg: unused
1580 *
1581 * Generally these operations are harmless.
1582 * File locking operations present an obvious mechanism
1583 * for passing information, so they require write access.
1584 *
1585 * Returns 0 if current has access, error code otherwise
1586 */
smack_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)1587 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1588 unsigned long arg)
1589 {
1590 struct smk_audit_info ad;
1591 int rc = 0;
1592 struct inode *inode = file_inode(file);
1593
1594 if (unlikely(IS_PRIVATE(inode)))
1595 return 0;
1596
1597 switch (cmd) {
1598 case F_GETLK:
1599 break;
1600 case F_SETLK:
1601 case F_SETLKW:
1602 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1603 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1604 rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1605 rc = smk_bu_file(file, MAY_LOCK, rc);
1606 break;
1607 case F_SETOWN:
1608 case F_SETSIG:
1609 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1610 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1611 rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1612 rc = smk_bu_file(file, MAY_WRITE, rc);
1613 break;
1614 default:
1615 break;
1616 }
1617
1618 return rc;
1619 }
1620
1621 /**
1622 * smack_mmap_file :
1623 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1624 * if mapping anonymous memory.
1625 * @file contains the file structure for file to map (may be NULL).
1626 * @reqprot contains the protection requested by the application.
1627 * @prot contains the protection that will be applied by the kernel.
1628 * @flags contains the operational flags.
1629 * Return 0 if permission is granted.
1630 */
smack_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)1631 static int smack_mmap_file(struct file *file,
1632 unsigned long reqprot, unsigned long prot,
1633 unsigned long flags)
1634 {
1635 struct smack_known *skp;
1636 struct smack_known *mkp;
1637 struct smack_rule *srp;
1638 struct task_smack *tsp;
1639 struct smack_known *okp;
1640 struct inode_smack *isp;
1641 struct superblock_smack *sbsp;
1642 int may;
1643 int mmay;
1644 int tmay;
1645 int rc;
1646
1647 if (file == NULL)
1648 return 0;
1649
1650 if (unlikely(IS_PRIVATE(file_inode(file))))
1651 return 0;
1652
1653 isp = smack_inode(file_inode(file));
1654 if (isp->smk_mmap == NULL)
1655 return 0;
1656 sbsp = smack_superblock(file_inode(file)->i_sb);
1657 if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
1658 isp->smk_mmap != sbsp->smk_root)
1659 return -EACCES;
1660 mkp = isp->smk_mmap;
1661
1662 tsp = smack_cred(current_cred());
1663 skp = smk_of_current();
1664 rc = 0;
1665
1666 rcu_read_lock();
1667 /*
1668 * For each Smack rule associated with the subject
1669 * label verify that the SMACK64MMAP also has access
1670 * to that rule's object label.
1671 */
1672 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1673 okp = srp->smk_object;
1674 /*
1675 * Matching labels always allows access.
1676 */
1677 if (mkp->smk_known == okp->smk_known)
1678 continue;
1679 /*
1680 * If there is a matching local rule take
1681 * that into account as well.
1682 */
1683 may = smk_access_entry(srp->smk_subject->smk_known,
1684 okp->smk_known,
1685 &tsp->smk_rules);
1686 if (may == -ENOENT)
1687 may = srp->smk_access;
1688 else
1689 may &= srp->smk_access;
1690 /*
1691 * If may is zero the SMACK64MMAP subject can't
1692 * possibly have less access.
1693 */
1694 if (may == 0)
1695 continue;
1696
1697 /*
1698 * Fetch the global list entry.
1699 * If there isn't one a SMACK64MMAP subject
1700 * can't have as much access as current.
1701 */
1702 mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1703 &mkp->smk_rules);
1704 if (mmay == -ENOENT) {
1705 rc = -EACCES;
1706 break;
1707 }
1708 /*
1709 * If there is a local entry it modifies the
1710 * potential access, too.
1711 */
1712 tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1713 &tsp->smk_rules);
1714 if (tmay != -ENOENT)
1715 mmay &= tmay;
1716
1717 /*
1718 * If there is any access available to current that is
1719 * not available to a SMACK64MMAP subject
1720 * deny access.
1721 */
1722 if ((may | mmay) != mmay) {
1723 rc = -EACCES;
1724 break;
1725 }
1726 }
1727
1728 rcu_read_unlock();
1729
1730 return rc;
1731 }
1732
1733 /**
1734 * smack_file_set_fowner - set the file security blob value
1735 * @file: object in question
1736 *
1737 */
smack_file_set_fowner(struct file * file)1738 static void smack_file_set_fowner(struct file *file)
1739 {
1740 struct smack_known **blob = smack_file(file);
1741
1742 *blob = smk_of_current();
1743 }
1744
1745 /**
1746 * smack_file_send_sigiotask - Smack on sigio
1747 * @tsk: The target task
1748 * @fown: the object the signal come from
1749 * @signum: unused
1750 *
1751 * Allow a privileged task to get signals even if it shouldn't
1752 *
1753 * Returns 0 if a subject with the object's smack could
1754 * write to the task, an error code otherwise.
1755 */
smack_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)1756 static int smack_file_send_sigiotask(struct task_struct *tsk,
1757 struct fown_struct *fown, int signum)
1758 {
1759 struct smack_known **blob;
1760 struct smack_known *skp;
1761 struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1762 const struct cred *tcred;
1763 struct file *file;
1764 int rc;
1765 struct smk_audit_info ad;
1766
1767 /*
1768 * struct fown_struct is never outside the context of a struct file
1769 */
1770 file = container_of(fown, struct file, f_owner);
1771
1772 /* we don't log here as rc can be overriden */
1773 blob = smack_file(file);
1774 skp = *blob;
1775 rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
1776 rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1777
1778 rcu_read_lock();
1779 tcred = __task_cred(tsk);
1780 if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
1781 rc = 0;
1782 rcu_read_unlock();
1783
1784 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1785 smk_ad_setfield_u_tsk(&ad, tsk);
1786 smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1787 return rc;
1788 }
1789
1790 /**
1791 * smack_file_receive - Smack file receive check
1792 * @file: the object
1793 *
1794 * Returns 0 if current has access, error code otherwise
1795 */
smack_file_receive(struct file * file)1796 static int smack_file_receive(struct file *file)
1797 {
1798 int rc;
1799 int may = 0;
1800 struct smk_audit_info ad;
1801 struct inode *inode = file_inode(file);
1802 struct socket *sock;
1803 struct task_smack *tsp;
1804 struct socket_smack *ssp;
1805
1806 if (unlikely(IS_PRIVATE(inode)))
1807 return 0;
1808
1809 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1810 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1811
1812 if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
1813 sock = SOCKET_I(inode);
1814 ssp = sock->sk->sk_security;
1815 tsp = smack_cred(current_cred());
1816 /*
1817 * If the receiving process can't write to the
1818 * passed socket or if the passed socket can't
1819 * write to the receiving process don't accept
1820 * the passed socket.
1821 */
1822 rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
1823 rc = smk_bu_file(file, may, rc);
1824 if (rc < 0)
1825 return rc;
1826 rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
1827 rc = smk_bu_file(file, may, rc);
1828 return rc;
1829 }
1830 /*
1831 * This code relies on bitmasks.
1832 */
1833 if (file->f_mode & FMODE_READ)
1834 may = MAY_READ;
1835 if (file->f_mode & FMODE_WRITE)
1836 may |= MAY_WRITE;
1837
1838 rc = smk_curacc(smk_of_inode(inode), may, &ad);
1839 rc = smk_bu_file(file, may, rc);
1840 return rc;
1841 }
1842
1843 /**
1844 * smack_file_open - Smack dentry open processing
1845 * @file: the object
1846 *
1847 * Set the security blob in the file structure.
1848 * Allow the open only if the task has read access. There are
1849 * many read operations (e.g. fstat) that you can do with an
1850 * fd even if you have the file open write-only.
1851 *
1852 * Returns 0 if current has access, error code otherwise
1853 */
smack_file_open(struct file * file)1854 static int smack_file_open(struct file *file)
1855 {
1856 struct task_smack *tsp = smack_cred(file->f_cred);
1857 struct inode *inode = file_inode(file);
1858 struct smk_audit_info ad;
1859 int rc;
1860
1861 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1862 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1863 rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
1864 rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
1865
1866 return rc;
1867 }
1868
1869 /*
1870 * Task hooks
1871 */
1872
1873 /**
1874 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1875 * @cred: the new credentials
1876 * @gfp: the atomicity of any memory allocations
1877 *
1878 * Prepare a blank set of credentials for modification. This must allocate all
1879 * the memory the LSM module might require such that cred_transfer() can
1880 * complete without error.
1881 */
smack_cred_alloc_blank(struct cred * cred,gfp_t gfp)1882 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1883 {
1884 init_task_smack(smack_cred(cred), NULL, NULL);
1885 return 0;
1886 }
1887
1888
1889 /**
1890 * smack_cred_free - "free" task-level security credentials
1891 * @cred: the credentials in question
1892 *
1893 */
smack_cred_free(struct cred * cred)1894 static void smack_cred_free(struct cred *cred)
1895 {
1896 struct task_smack *tsp = smack_cred(cred);
1897 struct smack_rule *rp;
1898 struct list_head *l;
1899 struct list_head *n;
1900
1901 smk_destroy_label_list(&tsp->smk_relabel);
1902
1903 list_for_each_safe(l, n, &tsp->smk_rules) {
1904 rp = list_entry(l, struct smack_rule, list);
1905 list_del(&rp->list);
1906 kmem_cache_free(smack_rule_cache, rp);
1907 }
1908 }
1909
1910 /**
1911 * smack_cred_prepare - prepare new set of credentials for modification
1912 * @new: the new credentials
1913 * @old: the original credentials
1914 * @gfp: the atomicity of any memory allocations
1915 *
1916 * Prepare a new set of credentials for modification.
1917 */
smack_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)1918 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1919 gfp_t gfp)
1920 {
1921 struct task_smack *old_tsp = smack_cred(old);
1922 struct task_smack *new_tsp = smack_cred(new);
1923 int rc;
1924
1925 init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
1926
1927 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1928 if (rc != 0)
1929 return rc;
1930
1931 rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
1932 gfp);
1933 return rc;
1934 }
1935
1936 /**
1937 * smack_cred_transfer - Transfer the old credentials to the new credentials
1938 * @new: the new credentials
1939 * @old: the original credentials
1940 *
1941 * Fill in a set of blank credentials from another set of credentials.
1942 */
smack_cred_transfer(struct cred * new,const struct cred * old)1943 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1944 {
1945 struct task_smack *old_tsp = smack_cred(old);
1946 struct task_smack *new_tsp = smack_cred(new);
1947
1948 new_tsp->smk_task = old_tsp->smk_task;
1949 new_tsp->smk_forked = old_tsp->smk_task;
1950 mutex_init(&new_tsp->smk_rules_lock);
1951 INIT_LIST_HEAD(&new_tsp->smk_rules);
1952
1953 /* cbs copy rule list */
1954 }
1955
1956 /**
1957 * smack_cred_getsecid - get the secid corresponding to a creds structure
1958 * @cred: the object creds
1959 * @secid: where to put the result
1960 *
1961 * Sets the secid to contain a u32 version of the smack label.
1962 */
smack_cred_getsecid(const struct cred * cred,u32 * secid)1963 static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
1964 {
1965 struct smack_known *skp;
1966
1967 rcu_read_lock();
1968 skp = smk_of_task(smack_cred(cred));
1969 *secid = skp->smk_secid;
1970 rcu_read_unlock();
1971 }
1972
1973 /**
1974 * smack_kernel_act_as - Set the subjective context in a set of credentials
1975 * @new: points to the set of credentials to be modified.
1976 * @secid: specifies the security ID to be set
1977 *
1978 * Set the security data for a kernel service.
1979 */
smack_kernel_act_as(struct cred * new,u32 secid)1980 static int smack_kernel_act_as(struct cred *new, u32 secid)
1981 {
1982 struct task_smack *new_tsp = smack_cred(new);
1983
1984 new_tsp->smk_task = smack_from_secid(secid);
1985 return 0;
1986 }
1987
1988 /**
1989 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1990 * @new: points to the set of credentials to be modified
1991 * @inode: points to the inode to use as a reference
1992 *
1993 * Set the file creation context in a set of credentials to the same
1994 * as the objective context of the specified inode
1995 */
smack_kernel_create_files_as(struct cred * new,struct inode * inode)1996 static int smack_kernel_create_files_as(struct cred *new,
1997 struct inode *inode)
1998 {
1999 struct inode_smack *isp = smack_inode(inode);
2000 struct task_smack *tsp = smack_cred(new);
2001
2002 tsp->smk_forked = isp->smk_inode;
2003 tsp->smk_task = tsp->smk_forked;
2004 return 0;
2005 }
2006
2007 /**
2008 * smk_curacc_on_task - helper to log task related access
2009 * @p: the task object
2010 * @access: the access requested
2011 * @caller: name of the calling function for audit
2012 *
2013 * Return 0 if access is permitted
2014 */
smk_curacc_on_task(struct task_struct * p,int access,const char * caller)2015 static int smk_curacc_on_task(struct task_struct *p, int access,
2016 const char *caller)
2017 {
2018 struct smk_audit_info ad;
2019 struct smack_known *skp = smk_of_task_struct_obj(p);
2020 int rc;
2021
2022 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
2023 smk_ad_setfield_u_tsk(&ad, p);
2024 rc = smk_curacc(skp, access, &ad);
2025 rc = smk_bu_task(p, access, rc);
2026 return rc;
2027 }
2028
2029 /**
2030 * smack_task_setpgid - Smack check on setting pgid
2031 * @p: the task object
2032 * @pgid: unused
2033 *
2034 * Return 0 if write access is permitted
2035 */
smack_task_setpgid(struct task_struct * p,pid_t pgid)2036 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
2037 {
2038 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2039 }
2040
2041 /**
2042 * smack_task_getpgid - Smack access check for getpgid
2043 * @p: the object task
2044 *
2045 * Returns 0 if current can read the object task, error code otherwise
2046 */
smack_task_getpgid(struct task_struct * p)2047 static int smack_task_getpgid(struct task_struct *p)
2048 {
2049 return smk_curacc_on_task(p, MAY_READ, __func__);
2050 }
2051
2052 /**
2053 * smack_task_getsid - Smack access check for getsid
2054 * @p: the object task
2055 *
2056 * Returns 0 if current can read the object task, error code otherwise
2057 */
smack_task_getsid(struct task_struct * p)2058 static int smack_task_getsid(struct task_struct *p)
2059 {
2060 return smk_curacc_on_task(p, MAY_READ, __func__);
2061 }
2062
2063 /**
2064 * smack_task_getsecid_subj - get the subjective secid of the task
2065 * @p: the task
2066 * @secid: where to put the result
2067 *
2068 * Sets the secid to contain a u32 version of the task's subjective smack label.
2069 */
smack_task_getsecid_subj(struct task_struct * p,u32 * secid)2070 static void smack_task_getsecid_subj(struct task_struct *p, u32 *secid)
2071 {
2072 struct smack_known *skp = smk_of_task_struct_subj(p);
2073
2074 *secid = skp->smk_secid;
2075 }
2076
2077 /**
2078 * smack_task_getsecid_obj - get the objective secid of the task
2079 * @p: the task
2080 * @secid: where to put the result
2081 *
2082 * Sets the secid to contain a u32 version of the task's objective smack label.
2083 */
smack_task_getsecid_obj(struct task_struct * p,u32 * secid)2084 static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
2085 {
2086 struct smack_known *skp = smk_of_task_struct_obj(p);
2087
2088 *secid = skp->smk_secid;
2089 }
2090
2091 /**
2092 * smack_task_setnice - Smack check on setting nice
2093 * @p: the task object
2094 * @nice: unused
2095 *
2096 * Return 0 if write access is permitted
2097 */
smack_task_setnice(struct task_struct * p,int nice)2098 static int smack_task_setnice(struct task_struct *p, int nice)
2099 {
2100 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2101 }
2102
2103 /**
2104 * smack_task_setioprio - Smack check on setting ioprio
2105 * @p: the task object
2106 * @ioprio: unused
2107 *
2108 * Return 0 if write access is permitted
2109 */
smack_task_setioprio(struct task_struct * p,int ioprio)2110 static int smack_task_setioprio(struct task_struct *p, int ioprio)
2111 {
2112 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2113 }
2114
2115 /**
2116 * smack_task_getioprio - Smack check on reading ioprio
2117 * @p: the task object
2118 *
2119 * Return 0 if read access is permitted
2120 */
smack_task_getioprio(struct task_struct * p)2121 static int smack_task_getioprio(struct task_struct *p)
2122 {
2123 return smk_curacc_on_task(p, MAY_READ, __func__);
2124 }
2125
2126 /**
2127 * smack_task_setscheduler - Smack check on setting scheduler
2128 * @p: the task object
2129 *
2130 * Return 0 if read access is permitted
2131 */
smack_task_setscheduler(struct task_struct * p)2132 static int smack_task_setscheduler(struct task_struct *p)
2133 {
2134 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2135 }
2136
2137 /**
2138 * smack_task_getscheduler - Smack check on reading scheduler
2139 * @p: the task object
2140 *
2141 * Return 0 if read access is permitted
2142 */
smack_task_getscheduler(struct task_struct * p)2143 static int smack_task_getscheduler(struct task_struct *p)
2144 {
2145 return smk_curacc_on_task(p, MAY_READ, __func__);
2146 }
2147
2148 /**
2149 * smack_task_movememory - Smack check on moving memory
2150 * @p: the task object
2151 *
2152 * Return 0 if write access is permitted
2153 */
smack_task_movememory(struct task_struct * p)2154 static int smack_task_movememory(struct task_struct *p)
2155 {
2156 return smk_curacc_on_task(p, MAY_WRITE, __func__);
2157 }
2158
2159 /**
2160 * smack_task_kill - Smack check on signal delivery
2161 * @p: the task object
2162 * @info: unused
2163 * @sig: unused
2164 * @cred: identifies the cred to use in lieu of current's
2165 *
2166 * Return 0 if write access is permitted
2167 *
2168 */
smack_task_kill(struct task_struct * p,struct kernel_siginfo * info,int sig,const struct cred * cred)2169 static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2170 int sig, const struct cred *cred)
2171 {
2172 struct smk_audit_info ad;
2173 struct smack_known *skp;
2174 struct smack_known *tkp = smk_of_task_struct_obj(p);
2175 int rc;
2176
2177 if (!sig)
2178 return 0; /* null signal; existence test */
2179
2180 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2181 smk_ad_setfield_u_tsk(&ad, p);
2182 /*
2183 * Sending a signal requires that the sender
2184 * can write the receiver.
2185 */
2186 if (cred == NULL) {
2187 rc = smk_curacc(tkp, MAY_DELIVER, &ad);
2188 rc = smk_bu_task(p, MAY_DELIVER, rc);
2189 return rc;
2190 }
2191 /*
2192 * If the cred isn't NULL we're dealing with some USB IO
2193 * specific behavior. This is not clean. For one thing
2194 * we can't take privilege into account.
2195 */
2196 skp = smk_of_task(smack_cred(cred));
2197 rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
2198 rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
2199 return rc;
2200 }
2201
2202 /**
2203 * smack_task_to_inode - copy task smack into the inode blob
2204 * @p: task to copy from
2205 * @inode: inode to copy to
2206 *
2207 * Sets the smack pointer in the inode security blob
2208 */
smack_task_to_inode(struct task_struct * p,struct inode * inode)2209 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2210 {
2211 struct inode_smack *isp = smack_inode(inode);
2212 struct smack_known *skp = smk_of_task_struct_obj(p);
2213
2214 isp->smk_inode = skp;
2215 isp->smk_flags |= SMK_INODE_INSTANT;
2216 }
2217
2218 /*
2219 * Socket hooks.
2220 */
2221
2222 /**
2223 * smack_sk_alloc_security - Allocate a socket blob
2224 * @sk: the socket
2225 * @family: unused
2226 * @gfp_flags: memory allocation flags
2227 *
2228 * Assign Smack pointers to current
2229 *
2230 * Returns 0 on success, -ENOMEM is there's no memory
2231 */
smack_sk_alloc_security(struct sock * sk,int family,gfp_t gfp_flags)2232 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2233 {
2234 struct smack_known *skp = smk_of_current();
2235 struct socket_smack *ssp;
2236
2237 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2238 if (ssp == NULL)
2239 return -ENOMEM;
2240
2241 /*
2242 * Sockets created by kernel threads receive web label.
2243 */
2244 if (unlikely(current->flags & PF_KTHREAD)) {
2245 ssp->smk_in = &smack_known_web;
2246 ssp->smk_out = &smack_known_web;
2247 } else {
2248 ssp->smk_in = skp;
2249 ssp->smk_out = skp;
2250 }
2251 ssp->smk_packet = NULL;
2252
2253 sk->sk_security = ssp;
2254
2255 return 0;
2256 }
2257
2258 /**
2259 * smack_sk_free_security - Free a socket blob
2260 * @sk: the socket
2261 *
2262 * Clears the blob pointer
2263 */
smack_sk_free_security(struct sock * sk)2264 static void smack_sk_free_security(struct sock *sk)
2265 {
2266 #ifdef SMACK_IPV6_PORT_LABELING
2267 struct smk_port_label *spp;
2268
2269 if (sk->sk_family == PF_INET6) {
2270 rcu_read_lock();
2271 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2272 if (spp->smk_sock != sk)
2273 continue;
2274 spp->smk_can_reuse = 1;
2275 break;
2276 }
2277 rcu_read_unlock();
2278 }
2279 #endif
2280 kfree(sk->sk_security);
2281 }
2282
2283 /**
2284 * smack_ipv4host_label - check host based restrictions
2285 * @sip: the object end
2286 *
2287 * looks for host based access restrictions
2288 *
2289 * This version will only be appropriate for really small sets of single label
2290 * hosts. The caller is responsible for ensuring that the RCU read lock is
2291 * taken before calling this function.
2292 *
2293 * Returns the label of the far end or NULL if it's not special.
2294 */
smack_ipv4host_label(struct sockaddr_in * sip)2295 static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2296 {
2297 struct smk_net4addr *snp;
2298 struct in_addr *siap = &sip->sin_addr;
2299
2300 if (siap->s_addr == 0)
2301 return NULL;
2302
2303 list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
2304 /*
2305 * we break after finding the first match because
2306 * the list is sorted from longest to shortest mask
2307 * so we have found the most specific match
2308 */
2309 if (snp->smk_host.s_addr ==
2310 (siap->s_addr & snp->smk_mask.s_addr))
2311 return snp->smk_label;
2312
2313 return NULL;
2314 }
2315
2316 /*
2317 * smk_ipv6_localhost - Check for local ipv6 host address
2318 * @sip: the address
2319 *
2320 * Returns boolean true if this is the localhost address
2321 */
smk_ipv6_localhost(struct sockaddr_in6 * sip)2322 static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
2323 {
2324 __be16 *be16p = (__be16 *)&sip->sin6_addr;
2325 __be32 *be32p = (__be32 *)&sip->sin6_addr;
2326
2327 if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
2328 ntohs(be16p[7]) == 1)
2329 return true;
2330 return false;
2331 }
2332
2333 /**
2334 * smack_ipv6host_label - check host based restrictions
2335 * @sip: the object end
2336 *
2337 * looks for host based access restrictions
2338 *
2339 * This version will only be appropriate for really small sets of single label
2340 * hosts. The caller is responsible for ensuring that the RCU read lock is
2341 * taken before calling this function.
2342 *
2343 * Returns the label of the far end or NULL if it's not special.
2344 */
smack_ipv6host_label(struct sockaddr_in6 * sip)2345 static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
2346 {
2347 struct smk_net6addr *snp;
2348 struct in6_addr *sap = &sip->sin6_addr;
2349 int i;
2350 int found = 0;
2351
2352 /*
2353 * It's local. Don't look for a host label.
2354 */
2355 if (smk_ipv6_localhost(sip))
2356 return NULL;
2357
2358 list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
2359 /*
2360 * If the label is NULL the entry has
2361 * been renounced. Ignore it.
2362 */
2363 if (snp->smk_label == NULL)
2364 continue;
2365 /*
2366 * we break after finding the first match because
2367 * the list is sorted from longest to shortest mask
2368 * so we have found the most specific match
2369 */
2370 for (found = 1, i = 0; i < 8; i++) {
2371 if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
2372 snp->smk_host.s6_addr16[i]) {
2373 found = 0;
2374 break;
2375 }
2376 }
2377 if (found)
2378 return snp->smk_label;
2379 }
2380
2381 return NULL;
2382 }
2383
2384 /**
2385 * smack_netlbl_add - Set the secattr on a socket
2386 * @sk: the socket
2387 *
2388 * Attach the outbound smack value (smk_out) to the socket.
2389 *
2390 * Returns 0 on success or an error code
2391 */
smack_netlbl_add(struct sock * sk)2392 static int smack_netlbl_add(struct sock *sk)
2393 {
2394 struct socket_smack *ssp = sk->sk_security;
2395 struct smack_known *skp = ssp->smk_out;
2396 int rc;
2397
2398 local_bh_disable();
2399 bh_lock_sock_nested(sk);
2400
2401 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2402 switch (rc) {
2403 case 0:
2404 ssp->smk_state = SMK_NETLBL_LABELED;
2405 break;
2406 case -EDESTADDRREQ:
2407 ssp->smk_state = SMK_NETLBL_REQSKB;
2408 rc = 0;
2409 break;
2410 }
2411
2412 bh_unlock_sock(sk);
2413 local_bh_enable();
2414
2415 return rc;
2416 }
2417
2418 /**
2419 * smack_netlbl_delete - Remove the secattr from a socket
2420 * @sk: the socket
2421 *
2422 * Remove the outbound smack value from a socket
2423 */
smack_netlbl_delete(struct sock * sk)2424 static void smack_netlbl_delete(struct sock *sk)
2425 {
2426 struct socket_smack *ssp = sk->sk_security;
2427
2428 /*
2429 * Take the label off the socket if one is set.
2430 */
2431 if (ssp->smk_state != SMK_NETLBL_LABELED)
2432 return;
2433
2434 local_bh_disable();
2435 bh_lock_sock_nested(sk);
2436 netlbl_sock_delattr(sk);
2437 bh_unlock_sock(sk);
2438 local_bh_enable();
2439 ssp->smk_state = SMK_NETLBL_UNLABELED;
2440 }
2441
2442 /**
2443 * smk_ipv4_check - Perform IPv4 host access checks
2444 * @sk: the socket
2445 * @sap: the destination address
2446 *
2447 * Set the correct secattr for the given socket based on the destination
2448 * address and perform any outbound access checks needed.
2449 *
2450 * Returns 0 on success or an error code.
2451 *
2452 */
smk_ipv4_check(struct sock * sk,struct sockaddr_in * sap)2453 static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
2454 {
2455 struct smack_known *skp;
2456 int rc = 0;
2457 struct smack_known *hkp;
2458 struct socket_smack *ssp = sk->sk_security;
2459 struct smk_audit_info ad;
2460
2461 rcu_read_lock();
2462 hkp = smack_ipv4host_label(sap);
2463 if (hkp != NULL) {
2464 #ifdef CONFIG_AUDIT
2465 struct lsm_network_audit net;
2466
2467 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2468 ad.a.u.net->family = sap->sin_family;
2469 ad.a.u.net->dport = sap->sin_port;
2470 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2471 #endif
2472 skp = ssp->smk_out;
2473 rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2474 rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2475 /*
2476 * Clear the socket netlabel if it's set.
2477 */
2478 if (!rc)
2479 smack_netlbl_delete(sk);
2480 }
2481 rcu_read_unlock();
2482
2483 return rc;
2484 }
2485
2486 /**
2487 * smk_ipv6_check - check Smack access
2488 * @subject: subject Smack label
2489 * @object: object Smack label
2490 * @address: address
2491 * @act: the action being taken
2492 *
2493 * Check an IPv6 access
2494 */
smk_ipv6_check(struct smack_known * subject,struct smack_known * object,struct sockaddr_in6 * address,int act)2495 static int smk_ipv6_check(struct smack_known *subject,
2496 struct smack_known *object,
2497 struct sockaddr_in6 *address, int act)
2498 {
2499 #ifdef CONFIG_AUDIT
2500 struct lsm_network_audit net;
2501 #endif
2502 struct smk_audit_info ad;
2503 int rc;
2504
2505 #ifdef CONFIG_AUDIT
2506 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2507 ad.a.u.net->family = PF_INET6;
2508 ad.a.u.net->dport = ntohs(address->sin6_port);
2509 if (act == SMK_RECEIVING)
2510 ad.a.u.net->v6info.saddr = address->sin6_addr;
2511 else
2512 ad.a.u.net->v6info.daddr = address->sin6_addr;
2513 #endif
2514 rc = smk_access(subject, object, MAY_WRITE, &ad);
2515 rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
2516 return rc;
2517 }
2518
2519 #ifdef SMACK_IPV6_PORT_LABELING
2520 /**
2521 * smk_ipv6_port_label - Smack port access table management
2522 * @sock: socket
2523 * @address: address
2524 *
2525 * Create or update the port list entry
2526 */
smk_ipv6_port_label(struct socket * sock,struct sockaddr * address)2527 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2528 {
2529 struct sock *sk = sock->sk;
2530 struct sockaddr_in6 *addr6;
2531 struct socket_smack *ssp = sock->sk->sk_security;
2532 struct smk_port_label *spp;
2533 unsigned short port = 0;
2534
2535 if (address == NULL) {
2536 /*
2537 * This operation is changing the Smack information
2538 * on the bound socket. Take the changes to the port
2539 * as well.
2540 */
2541 rcu_read_lock();
2542 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2543 if (sk != spp->smk_sock)
2544 continue;
2545 spp->smk_in = ssp->smk_in;
2546 spp->smk_out = ssp->smk_out;
2547 rcu_read_unlock();
2548 return;
2549 }
2550 /*
2551 * A NULL address is only used for updating existing
2552 * bound entries. If there isn't one, it's OK.
2553 */
2554 rcu_read_unlock();
2555 return;
2556 }
2557
2558 addr6 = (struct sockaddr_in6 *)address;
2559 port = ntohs(addr6->sin6_port);
2560 /*
2561 * This is a special case that is safely ignored.
2562 */
2563 if (port == 0)
2564 return;
2565
2566 /*
2567 * Look for an existing port list entry.
2568 * This is an indication that a port is getting reused.
2569 */
2570 rcu_read_lock();
2571 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2572 if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2573 continue;
2574 if (spp->smk_can_reuse != 1) {
2575 rcu_read_unlock();
2576 return;
2577 }
2578 spp->smk_port = port;
2579 spp->smk_sock = sk;
2580 spp->smk_in = ssp->smk_in;
2581 spp->smk_out = ssp->smk_out;
2582 spp->smk_can_reuse = 0;
2583 rcu_read_unlock();
2584 return;
2585 }
2586 rcu_read_unlock();
2587 /*
2588 * A new port entry is required.
2589 */
2590 spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2591 if (spp == NULL)
2592 return;
2593
2594 spp->smk_port = port;
2595 spp->smk_sock = sk;
2596 spp->smk_in = ssp->smk_in;
2597 spp->smk_out = ssp->smk_out;
2598 spp->smk_sock_type = sock->type;
2599 spp->smk_can_reuse = 0;
2600
2601 mutex_lock(&smack_ipv6_lock);
2602 list_add_rcu(&spp->list, &smk_ipv6_port_list);
2603 mutex_unlock(&smack_ipv6_lock);
2604 return;
2605 }
2606 #endif
2607
2608 /**
2609 * smk_ipv6_port_check - check Smack port access
2610 * @sk: socket
2611 * @address: address
2612 * @act: the action being taken
2613 *
2614 * Create or update the port list entry
2615 */
smk_ipv6_port_check(struct sock * sk,struct sockaddr_in6 * address,int act)2616 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2617 int act)
2618 {
2619 struct smk_port_label *spp;
2620 struct socket_smack *ssp = sk->sk_security;
2621 struct smack_known *skp = NULL;
2622 unsigned short port;
2623 struct smack_known *object;
2624
2625 if (act == SMK_RECEIVING) {
2626 skp = smack_ipv6host_label(address);
2627 object = ssp->smk_in;
2628 } else {
2629 skp = ssp->smk_out;
2630 object = smack_ipv6host_label(address);
2631 }
2632
2633 /*
2634 * The other end is a single label host.
2635 */
2636 if (skp != NULL && object != NULL)
2637 return smk_ipv6_check(skp, object, address, act);
2638 if (skp == NULL)
2639 skp = smack_net_ambient;
2640 if (object == NULL)
2641 object = smack_net_ambient;
2642
2643 /*
2644 * It's remote, so port lookup does no good.
2645 */
2646 if (!smk_ipv6_localhost(address))
2647 return smk_ipv6_check(skp, object, address, act);
2648
2649 /*
2650 * It's local so the send check has to have passed.
2651 */
2652 if (act == SMK_RECEIVING)
2653 return 0;
2654
2655 port = ntohs(address->sin6_port);
2656 rcu_read_lock();
2657 list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2658 if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2659 continue;
2660 object = spp->smk_in;
2661 if (act == SMK_CONNECTING)
2662 ssp->smk_packet = spp->smk_out;
2663 break;
2664 }
2665 rcu_read_unlock();
2666
2667 return smk_ipv6_check(skp, object, address, act);
2668 }
2669
2670 /**
2671 * smack_inode_setsecurity - set smack xattrs
2672 * @inode: the object
2673 * @name: attribute name
2674 * @value: attribute value
2675 * @size: size of the attribute
2676 * @flags: unused
2677 *
2678 * Sets the named attribute in the appropriate blob
2679 *
2680 * Returns 0 on success, or an error code
2681 */
smack_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)2682 static int smack_inode_setsecurity(struct inode *inode, const char *name,
2683 const void *value, size_t size, int flags)
2684 {
2685 struct smack_known *skp;
2686 struct inode_smack *nsp = smack_inode(inode);
2687 struct socket_smack *ssp;
2688 struct socket *sock;
2689 int rc = 0;
2690
2691 if (value == NULL || size > SMK_LONGLABEL || size == 0)
2692 return -EINVAL;
2693
2694 skp = smk_import_entry(value, size);
2695 if (IS_ERR(skp))
2696 return PTR_ERR(skp);
2697
2698 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2699 nsp->smk_inode = skp;
2700 nsp->smk_flags |= SMK_INODE_INSTANT;
2701 return 0;
2702 }
2703 /*
2704 * The rest of the Smack xattrs are only on sockets.
2705 */
2706 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2707 return -EOPNOTSUPP;
2708
2709 sock = SOCKET_I(inode);
2710 if (sock == NULL || sock->sk == NULL)
2711 return -EOPNOTSUPP;
2712
2713 ssp = sock->sk->sk_security;
2714
2715 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2716 ssp->smk_in = skp;
2717 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2718 ssp->smk_out = skp;
2719 if (sock->sk->sk_family == PF_INET) {
2720 rc = smack_netlbl_add(sock->sk);
2721 if (rc != 0)
2722 printk(KERN_WARNING
2723 "Smack: \"%s\" netlbl error %d.\n",
2724 __func__, -rc);
2725 }
2726 } else
2727 return -EOPNOTSUPP;
2728
2729 #ifdef SMACK_IPV6_PORT_LABELING
2730 if (sock->sk->sk_family == PF_INET6)
2731 smk_ipv6_port_label(sock, NULL);
2732 #endif
2733
2734 return 0;
2735 }
2736
2737 /**
2738 * smack_socket_post_create - finish socket setup
2739 * @sock: the socket
2740 * @family: protocol family
2741 * @type: unused
2742 * @protocol: unused
2743 * @kern: unused
2744 *
2745 * Sets the netlabel information on the socket
2746 *
2747 * Returns 0 on success, and error code otherwise
2748 */
smack_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)2749 static int smack_socket_post_create(struct socket *sock, int family,
2750 int type, int protocol, int kern)
2751 {
2752 struct socket_smack *ssp;
2753
2754 if (sock->sk == NULL)
2755 return 0;
2756
2757 /*
2758 * Sockets created by kernel threads receive web label.
2759 */
2760 if (unlikely(current->flags & PF_KTHREAD)) {
2761 ssp = sock->sk->sk_security;
2762 ssp->smk_in = &smack_known_web;
2763 ssp->smk_out = &smack_known_web;
2764 }
2765
2766 if (family != PF_INET)
2767 return 0;
2768 /*
2769 * Set the outbound netlbl.
2770 */
2771 return smack_netlbl_add(sock->sk);
2772 }
2773
2774 /**
2775 * smack_socket_socketpair - create socket pair
2776 * @socka: one socket
2777 * @sockb: another socket
2778 *
2779 * Cross reference the peer labels for SO_PEERSEC
2780 *
2781 * Returns 0
2782 */
smack_socket_socketpair(struct socket * socka,struct socket * sockb)2783 static int smack_socket_socketpair(struct socket *socka,
2784 struct socket *sockb)
2785 {
2786 struct socket_smack *asp = socka->sk->sk_security;
2787 struct socket_smack *bsp = sockb->sk->sk_security;
2788
2789 asp->smk_packet = bsp->smk_out;
2790 bsp->smk_packet = asp->smk_out;
2791
2792 return 0;
2793 }
2794
2795 #ifdef SMACK_IPV6_PORT_LABELING
2796 /**
2797 * smack_socket_bind - record port binding information.
2798 * @sock: the socket
2799 * @address: the port address
2800 * @addrlen: size of the address
2801 *
2802 * Records the label bound to a port.
2803 *
2804 * Returns 0 on success, and error code otherwise
2805 */
smack_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)2806 static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2807 int addrlen)
2808 {
2809 if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
2810 if (addrlen < SIN6_LEN_RFC2133 ||
2811 address->sa_family != AF_INET6)
2812 return -EINVAL;
2813 smk_ipv6_port_label(sock, address);
2814 }
2815 return 0;
2816 }
2817 #endif /* SMACK_IPV6_PORT_LABELING */
2818
2819 /**
2820 * smack_socket_connect - connect access check
2821 * @sock: the socket
2822 * @sap: the other end
2823 * @addrlen: size of sap
2824 *
2825 * Verifies that a connection may be possible
2826 *
2827 * Returns 0 on success, and error code otherwise
2828 */
smack_socket_connect(struct socket * sock,struct sockaddr * sap,int addrlen)2829 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2830 int addrlen)
2831 {
2832 int rc = 0;
2833
2834 if (sock->sk == NULL)
2835 return 0;
2836 if (sock->sk->sk_family != PF_INET &&
2837 (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
2838 return 0;
2839 if (addrlen < offsetofend(struct sockaddr, sa_family))
2840 return 0;
2841 if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
2842 struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
2843 struct smack_known *rsp = NULL;
2844
2845 if (addrlen < SIN6_LEN_RFC2133)
2846 return 0;
2847 if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
2848 rsp = smack_ipv6host_label(sip);
2849 if (rsp != NULL) {
2850 struct socket_smack *ssp = sock->sk->sk_security;
2851
2852 rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
2853 SMK_CONNECTING);
2854 }
2855 if (__is_defined(SMACK_IPV6_PORT_LABELING))
2856 rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
2857
2858 return rc;
2859 }
2860 if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
2861 return 0;
2862 rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
2863 return rc;
2864 }
2865
2866 /**
2867 * smack_flags_to_may - convert S_ to MAY_ values
2868 * @flags: the S_ value
2869 *
2870 * Returns the equivalent MAY_ value
2871 */
smack_flags_to_may(int flags)2872 static int smack_flags_to_may(int flags)
2873 {
2874 int may = 0;
2875
2876 if (flags & S_IRUGO)
2877 may |= MAY_READ;
2878 if (flags & S_IWUGO)
2879 may |= MAY_WRITE;
2880 if (flags & S_IXUGO)
2881 may |= MAY_EXEC;
2882
2883 return may;
2884 }
2885
2886 /**
2887 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2888 * @msg: the object
2889 *
2890 * Returns 0
2891 */
smack_msg_msg_alloc_security(struct msg_msg * msg)2892 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2893 {
2894 struct smack_known **blob = smack_msg_msg(msg);
2895
2896 *blob = smk_of_current();
2897 return 0;
2898 }
2899
2900 /**
2901 * smack_of_ipc - the smack pointer for the ipc
2902 * @isp: the object
2903 *
2904 * Returns a pointer to the smack value
2905 */
smack_of_ipc(struct kern_ipc_perm * isp)2906 static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
2907 {
2908 struct smack_known **blob = smack_ipc(isp);
2909
2910 return *blob;
2911 }
2912
2913 /**
2914 * smack_ipc_alloc_security - Set the security blob for ipc
2915 * @isp: the object
2916 *
2917 * Returns 0
2918 */
smack_ipc_alloc_security(struct kern_ipc_perm * isp)2919 static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
2920 {
2921 struct smack_known **blob = smack_ipc(isp);
2922
2923 *blob = smk_of_current();
2924 return 0;
2925 }
2926
2927 /**
2928 * smk_curacc_shm : check if current has access on shm
2929 * @isp : the object
2930 * @access : access requested
2931 *
2932 * Returns 0 if current has the requested access, error code otherwise
2933 */
smk_curacc_shm(struct kern_ipc_perm * isp,int access)2934 static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
2935 {
2936 struct smack_known *ssp = smack_of_ipc(isp);
2937 struct smk_audit_info ad;
2938 int rc;
2939
2940 #ifdef CONFIG_AUDIT
2941 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2942 ad.a.u.ipc_id = isp->id;
2943 #endif
2944 rc = smk_curacc(ssp, access, &ad);
2945 rc = smk_bu_current("shm", ssp, access, rc);
2946 return rc;
2947 }
2948
2949 /**
2950 * smack_shm_associate - Smack access check for shm
2951 * @isp: the object
2952 * @shmflg: access requested
2953 *
2954 * Returns 0 if current has the requested access, error code otherwise
2955 */
smack_shm_associate(struct kern_ipc_perm * isp,int shmflg)2956 static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
2957 {
2958 int may;
2959
2960 may = smack_flags_to_may(shmflg);
2961 return smk_curacc_shm(isp, may);
2962 }
2963
2964 /**
2965 * smack_shm_shmctl - Smack access check for shm
2966 * @isp: the object
2967 * @cmd: what it wants to do
2968 *
2969 * Returns 0 if current has the requested access, error code otherwise
2970 */
smack_shm_shmctl(struct kern_ipc_perm * isp,int cmd)2971 static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
2972 {
2973 int may;
2974
2975 switch (cmd) {
2976 case IPC_STAT:
2977 case SHM_STAT:
2978 case SHM_STAT_ANY:
2979 may = MAY_READ;
2980 break;
2981 case IPC_SET:
2982 case SHM_LOCK:
2983 case SHM_UNLOCK:
2984 case IPC_RMID:
2985 may = MAY_READWRITE;
2986 break;
2987 case IPC_INFO:
2988 case SHM_INFO:
2989 /*
2990 * System level information.
2991 */
2992 return 0;
2993 default:
2994 return -EINVAL;
2995 }
2996 return smk_curacc_shm(isp, may);
2997 }
2998
2999 /**
3000 * smack_shm_shmat - Smack access for shmat
3001 * @isp: the object
3002 * @shmaddr: unused
3003 * @shmflg: access requested
3004 *
3005 * Returns 0 if current has the requested access, error code otherwise
3006 */
smack_shm_shmat(struct kern_ipc_perm * isp,char __user * shmaddr,int shmflg)3007 static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
3008 int shmflg)
3009 {
3010 int may;
3011
3012 may = smack_flags_to_may(shmflg);
3013 return smk_curacc_shm(isp, may);
3014 }
3015
3016 /**
3017 * smk_curacc_sem : check if current has access on sem
3018 * @isp : the object
3019 * @access : access requested
3020 *
3021 * Returns 0 if current has the requested access, error code otherwise
3022 */
smk_curacc_sem(struct kern_ipc_perm * isp,int access)3023 static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
3024 {
3025 struct smack_known *ssp = smack_of_ipc(isp);
3026 struct smk_audit_info ad;
3027 int rc;
3028
3029 #ifdef CONFIG_AUDIT
3030 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3031 ad.a.u.ipc_id = isp->id;
3032 #endif
3033 rc = smk_curacc(ssp, access, &ad);
3034 rc = smk_bu_current("sem", ssp, access, rc);
3035 return rc;
3036 }
3037
3038 /**
3039 * smack_sem_associate - Smack access check for sem
3040 * @isp: the object
3041 * @semflg: access requested
3042 *
3043 * Returns 0 if current has the requested access, error code otherwise
3044 */
smack_sem_associate(struct kern_ipc_perm * isp,int semflg)3045 static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3046 {
3047 int may;
3048
3049 may = smack_flags_to_may(semflg);
3050 return smk_curacc_sem(isp, may);
3051 }
3052
3053 /**
3054 * smack_sem_shmctl - Smack access check for sem
3055 * @isp: the object
3056 * @cmd: what it wants to do
3057 *
3058 * Returns 0 if current has the requested access, error code otherwise
3059 */
smack_sem_semctl(struct kern_ipc_perm * isp,int cmd)3060 static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3061 {
3062 int may;
3063
3064 switch (cmd) {
3065 case GETPID:
3066 case GETNCNT:
3067 case GETZCNT:
3068 case GETVAL:
3069 case GETALL:
3070 case IPC_STAT:
3071 case SEM_STAT:
3072 case SEM_STAT_ANY:
3073 may = MAY_READ;
3074 break;
3075 case SETVAL:
3076 case SETALL:
3077 case IPC_RMID:
3078 case IPC_SET:
3079 may = MAY_READWRITE;
3080 break;
3081 case IPC_INFO:
3082 case SEM_INFO:
3083 /*
3084 * System level information
3085 */
3086 return 0;
3087 default:
3088 return -EINVAL;
3089 }
3090
3091 return smk_curacc_sem(isp, may);
3092 }
3093
3094 /**
3095 * smack_sem_semop - Smack checks of semaphore operations
3096 * @isp: the object
3097 * @sops: unused
3098 * @nsops: unused
3099 * @alter: unused
3100 *
3101 * Treated as read and write in all cases.
3102 *
3103 * Returns 0 if access is allowed, error code otherwise
3104 */
smack_sem_semop(struct kern_ipc_perm * isp,struct sembuf * sops,unsigned nsops,int alter)3105 static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3106 unsigned nsops, int alter)
3107 {
3108 return smk_curacc_sem(isp, MAY_READWRITE);
3109 }
3110
3111 /**
3112 * smk_curacc_msq : helper to check if current has access on msq
3113 * @isp : the msq
3114 * @access : access requested
3115 *
3116 * return 0 if current has access, error otherwise
3117 */
smk_curacc_msq(struct kern_ipc_perm * isp,int access)3118 static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
3119 {
3120 struct smack_known *msp = smack_of_ipc(isp);
3121 struct smk_audit_info ad;
3122 int rc;
3123
3124 #ifdef CONFIG_AUDIT
3125 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3126 ad.a.u.ipc_id = isp->id;
3127 #endif
3128 rc = smk_curacc(msp, access, &ad);
3129 rc = smk_bu_current("msq", msp, access, rc);
3130 return rc;
3131 }
3132
3133 /**
3134 * smack_msg_queue_associate - Smack access check for msg_queue
3135 * @isp: the object
3136 * @msqflg: access requested
3137 *
3138 * Returns 0 if current has the requested access, error code otherwise
3139 */
smack_msg_queue_associate(struct kern_ipc_perm * isp,int msqflg)3140 static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3141 {
3142 int may;
3143
3144 may = smack_flags_to_may(msqflg);
3145 return smk_curacc_msq(isp, may);
3146 }
3147
3148 /**
3149 * smack_msg_queue_msgctl - Smack access check for msg_queue
3150 * @isp: the object
3151 * @cmd: what it wants to do
3152 *
3153 * Returns 0 if current has the requested access, error code otherwise
3154 */
smack_msg_queue_msgctl(struct kern_ipc_perm * isp,int cmd)3155 static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3156 {
3157 int may;
3158
3159 switch (cmd) {
3160 case IPC_STAT:
3161 case MSG_STAT:
3162 case MSG_STAT_ANY:
3163 may = MAY_READ;
3164 break;
3165 case IPC_SET:
3166 case IPC_RMID:
3167 may = MAY_READWRITE;
3168 break;
3169 case IPC_INFO:
3170 case MSG_INFO:
3171 /*
3172 * System level information
3173 */
3174 return 0;
3175 default:
3176 return -EINVAL;
3177 }
3178
3179 return smk_curacc_msq(isp, may);
3180 }
3181
3182 /**
3183 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3184 * @isp: the object
3185 * @msg: unused
3186 * @msqflg: access requested
3187 *
3188 * Returns 0 if current has the requested access, error code otherwise
3189 */
smack_msg_queue_msgsnd(struct kern_ipc_perm * isp,struct msg_msg * msg,int msqflg)3190 static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3191 int msqflg)
3192 {
3193 int may;
3194
3195 may = smack_flags_to_may(msqflg);
3196 return smk_curacc_msq(isp, may);
3197 }
3198
3199 /**
3200 * smack_msg_queue_msgsnd - Smack access check for msg_queue
3201 * @isp: the object
3202 * @msg: unused
3203 * @target: unused
3204 * @type: unused
3205 * @mode: unused
3206 *
3207 * Returns 0 if current has read and write access, error code otherwise
3208 */
smack_msg_queue_msgrcv(struct kern_ipc_perm * isp,struct msg_msg * msg,struct task_struct * target,long type,int mode)3209 static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp, struct msg_msg *msg,
3210 struct task_struct *target, long type, int mode)
3211 {
3212 return smk_curacc_msq(isp, MAY_READWRITE);
3213 }
3214
3215 /**
3216 * smack_ipc_permission - Smack access for ipc_permission()
3217 * @ipp: the object permissions
3218 * @flag: access requested
3219 *
3220 * Returns 0 if current has read and write access, error code otherwise
3221 */
smack_ipc_permission(struct kern_ipc_perm * ipp,short flag)3222 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3223 {
3224 struct smack_known **blob = smack_ipc(ipp);
3225 struct smack_known *iskp = *blob;
3226 int may = smack_flags_to_may(flag);
3227 struct smk_audit_info ad;
3228 int rc;
3229
3230 #ifdef CONFIG_AUDIT
3231 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3232 ad.a.u.ipc_id = ipp->id;
3233 #endif
3234 rc = smk_curacc(iskp, may, &ad);
3235 rc = smk_bu_current("svipc", iskp, may, rc);
3236 return rc;
3237 }
3238
3239 /**
3240 * smack_ipc_getsecid - Extract smack security id
3241 * @ipp: the object permissions
3242 * @secid: where result will be saved
3243 */
smack_ipc_getsecid(struct kern_ipc_perm * ipp,u32 * secid)3244 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3245 {
3246 struct smack_known **blob = smack_ipc(ipp);
3247 struct smack_known *iskp = *blob;
3248
3249 *secid = iskp->smk_secid;
3250 }
3251
3252 /**
3253 * smack_d_instantiate - Make sure the blob is correct on an inode
3254 * @opt_dentry: dentry where inode will be attached
3255 * @inode: the object
3256 *
3257 * Set the inode's security blob if it hasn't been done already.
3258 */
smack_d_instantiate(struct dentry * opt_dentry,struct inode * inode)3259 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3260 {
3261 struct super_block *sbp;
3262 struct superblock_smack *sbsp;
3263 struct inode_smack *isp;
3264 struct smack_known *skp;
3265 struct smack_known *ckp = smk_of_current();
3266 struct smack_known *final;
3267 char trattr[TRANS_TRUE_SIZE];
3268 int transflag = 0;
3269 int rc;
3270 struct dentry *dp;
3271
3272 if (inode == NULL)
3273 return;
3274
3275 isp = smack_inode(inode);
3276
3277 /*
3278 * If the inode is already instantiated
3279 * take the quick way out
3280 */
3281 if (isp->smk_flags & SMK_INODE_INSTANT)
3282 return;
3283
3284 sbp = inode->i_sb;
3285 sbsp = smack_superblock(sbp);
3286 /*
3287 * We're going to use the superblock default label
3288 * if there's no label on the file.
3289 */
3290 final = sbsp->smk_default;
3291
3292 /*
3293 * If this is the root inode the superblock
3294 * may be in the process of initialization.
3295 * If that is the case use the root value out
3296 * of the superblock.
3297 */
3298 if (opt_dentry->d_parent == opt_dentry) {
3299 switch (sbp->s_magic) {
3300 case CGROUP_SUPER_MAGIC:
3301 case CGROUP2_SUPER_MAGIC:
3302 /*
3303 * The cgroup filesystem is never mounted,
3304 * so there's no opportunity to set the mount
3305 * options.
3306 */
3307 sbsp->smk_root = &smack_known_star;
3308 sbsp->smk_default = &smack_known_star;
3309 isp->smk_inode = sbsp->smk_root;
3310 break;
3311 case TMPFS_MAGIC:
3312 /*
3313 * What about shmem/tmpfs anonymous files with dentry
3314 * obtained from d_alloc_pseudo()?
3315 */
3316 isp->smk_inode = smk_of_current();
3317 break;
3318 case PIPEFS_MAGIC:
3319 isp->smk_inode = smk_of_current();
3320 break;
3321 case SOCKFS_MAGIC:
3322 /*
3323 * Socket access is controlled by the socket
3324 * structures associated with the task involved.
3325 */
3326 isp->smk_inode = &smack_known_star;
3327 break;
3328 default:
3329 isp->smk_inode = sbsp->smk_root;
3330 break;
3331 }
3332 isp->smk_flags |= SMK_INODE_INSTANT;
3333 return;
3334 }
3335
3336 /*
3337 * This is pretty hackish.
3338 * Casey says that we shouldn't have to do
3339 * file system specific code, but it does help
3340 * with keeping it simple.
3341 */
3342 switch (sbp->s_magic) {
3343 case SMACK_MAGIC:
3344 case CGROUP_SUPER_MAGIC:
3345 case CGROUP2_SUPER_MAGIC:
3346 /*
3347 * Casey says that it's a little embarrassing
3348 * that the smack file system doesn't do
3349 * extended attributes.
3350 *
3351 * Cgroupfs is special
3352 */
3353 final = &smack_known_star;
3354 break;
3355 case DEVPTS_SUPER_MAGIC:
3356 /*
3357 * devpts seems content with the label of the task.
3358 * Programs that change smack have to treat the
3359 * pty with respect.
3360 */
3361 final = ckp;
3362 break;
3363 case PROC_SUPER_MAGIC:
3364 /*
3365 * Casey says procfs appears not to care.
3366 * The superblock default suffices.
3367 */
3368 break;
3369 case TMPFS_MAGIC:
3370 /*
3371 * Device labels should come from the filesystem,
3372 * but watch out, because they're volitile,
3373 * getting recreated on every reboot.
3374 */
3375 final = &smack_known_star;
3376 /*
3377 * If a smack value has been set we want to use it,
3378 * but since tmpfs isn't giving us the opportunity
3379 * to set mount options simulate setting the
3380 * superblock default.
3381 */
3382 fallthrough;
3383 default:
3384 /*
3385 * This isn't an understood special case.
3386 * Get the value from the xattr.
3387 */
3388
3389 /*
3390 * UNIX domain sockets use lower level socket data.
3391 */
3392 if (S_ISSOCK(inode->i_mode)) {
3393 final = &smack_known_star;
3394 break;
3395 }
3396 /*
3397 * No xattr support means, alas, no SMACK label.
3398 * Use the aforeapplied default.
3399 * It would be curious if the label of the task
3400 * does not match that assigned.
3401 */
3402 if (!(inode->i_opflags & IOP_XATTR))
3403 break;
3404 /*
3405 * Get the dentry for xattr.
3406 */
3407 dp = dget(opt_dentry);
3408 skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3409 if (!IS_ERR_OR_NULL(skp))
3410 final = skp;
3411
3412 /*
3413 * Transmuting directory
3414 */
3415 if (S_ISDIR(inode->i_mode)) {
3416 /*
3417 * If this is a new directory and the label was
3418 * transmuted when the inode was initialized
3419 * set the transmute attribute on the directory
3420 * and mark the inode.
3421 *
3422 * If there is a transmute attribute on the
3423 * directory mark the inode.
3424 */
3425 if (isp->smk_flags & SMK_INODE_CHANGED) {
3426 isp->smk_flags &= ~SMK_INODE_CHANGED;
3427 rc = __vfs_setxattr(&init_user_ns, dp, inode,
3428 XATTR_NAME_SMACKTRANSMUTE,
3429 TRANS_TRUE, TRANS_TRUE_SIZE,
3430 0);
3431 } else {
3432 rc = __vfs_getxattr(dp, inode,
3433 XATTR_NAME_SMACKTRANSMUTE, trattr,
3434 TRANS_TRUE_SIZE);
3435 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3436 TRANS_TRUE_SIZE) != 0)
3437 rc = -EINVAL;
3438 }
3439 if (rc >= 0)
3440 transflag = SMK_INODE_TRANSMUTE;
3441 }
3442 /*
3443 * Don't let the exec or mmap label be "*" or "@".
3444 */
3445 skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3446 if (IS_ERR(skp) || skp == &smack_known_star ||
3447 skp == &smack_known_web)
3448 skp = NULL;
3449 isp->smk_task = skp;
3450
3451 skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3452 if (IS_ERR(skp) || skp == &smack_known_star ||
3453 skp == &smack_known_web)
3454 skp = NULL;
3455 isp->smk_mmap = skp;
3456
3457 dput(dp);
3458 break;
3459 }
3460
3461 if (final == NULL)
3462 isp->smk_inode = ckp;
3463 else
3464 isp->smk_inode = final;
3465
3466 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3467
3468 return;
3469 }
3470
3471 /**
3472 * smack_getprocattr - Smack process attribute access
3473 * @p: the object task
3474 * @name: the name of the attribute in /proc/.../attr
3475 * @value: where to put the result
3476 *
3477 * Places a copy of the task Smack into value
3478 *
3479 * Returns the length of the smack label or an error code
3480 */
smack_getprocattr(struct task_struct * p,char * name,char ** value)3481 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
3482 {
3483 struct smack_known *skp = smk_of_task_struct_obj(p);
3484 char *cp;
3485 int slen;
3486
3487 if (strcmp(name, "current") != 0)
3488 return -EINVAL;
3489
3490 cp = kstrdup(skp->smk_known, GFP_KERNEL);
3491 if (cp == NULL)
3492 return -ENOMEM;
3493
3494 slen = strlen(cp);
3495 *value = cp;
3496 return slen;
3497 }
3498
3499 /**
3500 * smack_setprocattr - Smack process attribute setting
3501 * @name: the name of the attribute in /proc/.../attr
3502 * @value: the value to set
3503 * @size: the size of the value
3504 *
3505 * Sets the Smack value of the task. Only setting self
3506 * is permitted and only with privilege
3507 *
3508 * Returns the length of the smack label or an error code
3509 */
smack_setprocattr(const char * name,void * value,size_t size)3510 static int smack_setprocattr(const char *name, void *value, size_t size)
3511 {
3512 struct task_smack *tsp = smack_cred(current_cred());
3513 struct cred *new;
3514 struct smack_known *skp;
3515 struct smack_known_list_elem *sklep;
3516 int rc;
3517
3518 if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3519 return -EPERM;
3520
3521 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3522 return -EINVAL;
3523
3524 if (strcmp(name, "current") != 0)
3525 return -EINVAL;
3526
3527 skp = smk_import_entry(value, size);
3528 if (IS_ERR(skp))
3529 return PTR_ERR(skp);
3530
3531 /*
3532 * No process is ever allowed the web ("@") label
3533 * and the star ("*") label.
3534 */
3535 if (skp == &smack_known_web || skp == &smack_known_star)
3536 return -EINVAL;
3537
3538 if (!smack_privileged(CAP_MAC_ADMIN)) {
3539 rc = -EPERM;
3540 list_for_each_entry(sklep, &tsp->smk_relabel, list)
3541 if (sklep->smk_label == skp) {
3542 rc = 0;
3543 break;
3544 }
3545 if (rc)
3546 return rc;
3547 }
3548
3549 new = prepare_creds();
3550 if (new == NULL)
3551 return -ENOMEM;
3552
3553 tsp = smack_cred(new);
3554 tsp->smk_task = skp;
3555 /*
3556 * process can change its label only once
3557 */
3558 smk_destroy_label_list(&tsp->smk_relabel);
3559
3560 commit_creds(new);
3561 return size;
3562 }
3563
3564 /**
3565 * smack_unix_stream_connect - Smack access on UDS
3566 * @sock: one sock
3567 * @other: the other sock
3568 * @newsk: unused
3569 *
3570 * Return 0 if a subject with the smack of sock could access
3571 * an object with the smack of other, otherwise an error code
3572 */
smack_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)3573 static int smack_unix_stream_connect(struct sock *sock,
3574 struct sock *other, struct sock *newsk)
3575 {
3576 struct smack_known *skp;
3577 struct smack_known *okp;
3578 struct socket_smack *ssp = sock->sk_security;
3579 struct socket_smack *osp = other->sk_security;
3580 struct socket_smack *nsp = newsk->sk_security;
3581 struct smk_audit_info ad;
3582 int rc = 0;
3583 #ifdef CONFIG_AUDIT
3584 struct lsm_network_audit net;
3585 #endif
3586
3587 if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3588 skp = ssp->smk_out;
3589 okp = osp->smk_in;
3590 #ifdef CONFIG_AUDIT
3591 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3592 smk_ad_setfield_u_net_sk(&ad, other);
3593 #endif
3594 rc = smk_access(skp, okp, MAY_WRITE, &ad);
3595 rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3596 if (rc == 0) {
3597 okp = osp->smk_out;
3598 skp = ssp->smk_in;
3599 rc = smk_access(okp, skp, MAY_WRITE, &ad);
3600 rc = smk_bu_note("UDS connect", okp, skp,
3601 MAY_WRITE, rc);
3602 }
3603 }
3604
3605 /*
3606 * Cross reference the peer labels for SO_PEERSEC.
3607 */
3608 if (rc == 0) {
3609 nsp->smk_packet = ssp->smk_out;
3610 ssp->smk_packet = osp->smk_out;
3611 }
3612
3613 return rc;
3614 }
3615
3616 /**
3617 * smack_unix_may_send - Smack access on UDS
3618 * @sock: one socket
3619 * @other: the other socket
3620 *
3621 * Return 0 if a subject with the smack of sock could access
3622 * an object with the smack of other, otherwise an error code
3623 */
smack_unix_may_send(struct socket * sock,struct socket * other)3624 static int smack_unix_may_send(struct socket *sock, struct socket *other)
3625 {
3626 struct socket_smack *ssp = sock->sk->sk_security;
3627 struct socket_smack *osp = other->sk->sk_security;
3628 struct smk_audit_info ad;
3629 int rc;
3630
3631 #ifdef CONFIG_AUDIT
3632 struct lsm_network_audit net;
3633
3634 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3635 smk_ad_setfield_u_net_sk(&ad, other->sk);
3636 #endif
3637
3638 if (smack_privileged(CAP_MAC_OVERRIDE))
3639 return 0;
3640
3641 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3642 rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3643 return rc;
3644 }
3645
3646 /**
3647 * smack_socket_sendmsg - Smack check based on destination host
3648 * @sock: the socket
3649 * @msg: the message
3650 * @size: the size of the message
3651 *
3652 * Return 0 if the current subject can write to the destination host.
3653 * For IPv4 this is only a question if the destination is a single label host.
3654 * For IPv6 this is a check against the label of the port.
3655 */
smack_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)3656 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3657 int size)
3658 {
3659 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3660 #if IS_ENABLED(CONFIG_IPV6)
3661 struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3662 #endif
3663 #ifdef SMACK_IPV6_SECMARK_LABELING
3664 struct socket_smack *ssp = sock->sk->sk_security;
3665 struct smack_known *rsp;
3666 #endif
3667 int rc = 0;
3668
3669 /*
3670 * Perfectly reasonable for this to be NULL
3671 */
3672 if (sip == NULL)
3673 return 0;
3674
3675 switch (sock->sk->sk_family) {
3676 case AF_INET:
3677 if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
3678 sip->sin_family != AF_INET)
3679 return -EINVAL;
3680 rc = smk_ipv4_check(sock->sk, sip);
3681 break;
3682 #if IS_ENABLED(CONFIG_IPV6)
3683 case AF_INET6:
3684 if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
3685 sap->sin6_family != AF_INET6)
3686 return -EINVAL;
3687 #ifdef SMACK_IPV6_SECMARK_LABELING
3688 rsp = smack_ipv6host_label(sap);
3689 if (rsp != NULL)
3690 rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
3691 SMK_CONNECTING);
3692 #endif
3693 #ifdef SMACK_IPV6_PORT_LABELING
3694 rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3695 #endif
3696 #endif /* IS_ENABLED(CONFIG_IPV6) */
3697 break;
3698 }
3699 return rc;
3700 }
3701
3702 /**
3703 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3704 * @sap: netlabel secattr
3705 * @ssp: socket security information
3706 *
3707 * Returns a pointer to a Smack label entry found on the label list.
3708 */
smack_from_secattr(struct netlbl_lsm_secattr * sap,struct socket_smack * ssp)3709 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3710 struct socket_smack *ssp)
3711 {
3712 struct smack_known *skp;
3713 int found = 0;
3714 int acat;
3715 int kcat;
3716
3717 /*
3718 * Netlabel found it in the cache.
3719 */
3720 if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
3721 return (struct smack_known *)sap->cache->data;
3722
3723 if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3724 /*
3725 * Looks like a fallback, which gives us a secid.
3726 */
3727 return smack_from_secid(sap->attr.secid);
3728
3729 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3730 /*
3731 * Looks like a CIPSO packet.
3732 * If there are flags but no level netlabel isn't
3733 * behaving the way we expect it to.
3734 *
3735 * Look it up in the label table
3736 * Without guidance regarding the smack value
3737 * for the packet fall back on the network
3738 * ambient value.
3739 */
3740 rcu_read_lock();
3741 list_for_each_entry_rcu(skp, &smack_known_list, list) {
3742 if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3743 continue;
3744 /*
3745 * Compare the catsets. Use the netlbl APIs.
3746 */
3747 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3748 if ((skp->smk_netlabel.flags &
3749 NETLBL_SECATTR_MLS_CAT) == 0)
3750 found = 1;
3751 break;
3752 }
3753 for (acat = -1, kcat = -1; acat == kcat; ) {
3754 acat = netlbl_catmap_walk(sap->attr.mls.cat,
3755 acat + 1);
3756 kcat = netlbl_catmap_walk(
3757 skp->smk_netlabel.attr.mls.cat,
3758 kcat + 1);
3759 if (acat < 0 || kcat < 0)
3760 break;
3761 }
3762 if (acat == kcat) {
3763 found = 1;
3764 break;
3765 }
3766 }
3767 rcu_read_unlock();
3768
3769 if (found)
3770 return skp;
3771
3772 if (ssp != NULL && ssp->smk_in == &smack_known_star)
3773 return &smack_known_web;
3774 return &smack_known_star;
3775 }
3776 /*
3777 * Without guidance regarding the smack value
3778 * for the packet fall back on the network
3779 * ambient value.
3780 */
3781 return smack_net_ambient;
3782 }
3783
3784 #if IS_ENABLED(CONFIG_IPV6)
smk_skb_to_addr_ipv6(struct sk_buff * skb,struct sockaddr_in6 * sip)3785 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3786 {
3787 u8 nexthdr;
3788 int offset;
3789 int proto = -EINVAL;
3790 struct ipv6hdr _ipv6h;
3791 struct ipv6hdr *ip6;
3792 __be16 frag_off;
3793 struct tcphdr _tcph, *th;
3794 struct udphdr _udph, *uh;
3795 struct dccp_hdr _dccph, *dh;
3796
3797 sip->sin6_port = 0;
3798
3799 offset = skb_network_offset(skb);
3800 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3801 if (ip6 == NULL)
3802 return -EINVAL;
3803 sip->sin6_addr = ip6->saddr;
3804
3805 nexthdr = ip6->nexthdr;
3806 offset += sizeof(_ipv6h);
3807 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3808 if (offset < 0)
3809 return -EINVAL;
3810
3811 proto = nexthdr;
3812 switch (proto) {
3813 case IPPROTO_TCP:
3814 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3815 if (th != NULL)
3816 sip->sin6_port = th->source;
3817 break;
3818 case IPPROTO_UDP:
3819 case IPPROTO_UDPLITE:
3820 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3821 if (uh != NULL)
3822 sip->sin6_port = uh->source;
3823 break;
3824 case IPPROTO_DCCP:
3825 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3826 if (dh != NULL)
3827 sip->sin6_port = dh->dccph_sport;
3828 break;
3829 }
3830 return proto;
3831 }
3832 #endif /* CONFIG_IPV6 */
3833
3834 /**
3835 * smack_from_skb - Smack data from the secmark in an skb
3836 * @skb: packet
3837 *
3838 * Returns smack_known of the secmark or NULL if that won't work.
3839 */
3840 #ifdef CONFIG_NETWORK_SECMARK
smack_from_skb(struct sk_buff * skb)3841 static struct smack_known *smack_from_skb(struct sk_buff *skb)
3842 {
3843 if (skb == NULL || skb->secmark == 0)
3844 return NULL;
3845
3846 return smack_from_secid(skb->secmark);
3847 }
3848 #else
smack_from_skb(struct sk_buff * skb)3849 static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
3850 {
3851 return NULL;
3852 }
3853 #endif
3854
3855 /**
3856 * smack_from_netlbl - Smack data from the IP options in an skb
3857 * @sk: socket data came in on
3858 * @family: address family
3859 * @skb: packet
3860 *
3861 * Find the Smack label in the IP options. If it hasn't been
3862 * added to the netlabel cache, add it here.
3863 *
3864 * Returns smack_known of the IP options or NULL if that won't work.
3865 */
smack_from_netlbl(const struct sock * sk,u16 family,struct sk_buff * skb)3866 static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
3867 struct sk_buff *skb)
3868 {
3869 struct netlbl_lsm_secattr secattr;
3870 struct socket_smack *ssp = NULL;
3871 struct smack_known *skp = NULL;
3872
3873 netlbl_secattr_init(&secattr);
3874
3875 if (sk)
3876 ssp = sk->sk_security;
3877
3878 if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
3879 skp = smack_from_secattr(&secattr, ssp);
3880 if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
3881 netlbl_cache_add(skb, family, &skp->smk_netlabel);
3882 }
3883
3884 netlbl_secattr_destroy(&secattr);
3885
3886 return skp;
3887 }
3888
3889 /**
3890 * smack_socket_sock_rcv_skb - Smack packet delivery access check
3891 * @sk: socket
3892 * @skb: packet
3893 *
3894 * Returns 0 if the packet should be delivered, an error code otherwise
3895 */
smack_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)3896 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3897 {
3898 struct socket_smack *ssp = sk->sk_security;
3899 struct smack_known *skp = NULL;
3900 int rc = 0;
3901 struct smk_audit_info ad;
3902 u16 family = sk->sk_family;
3903 #ifdef CONFIG_AUDIT
3904 struct lsm_network_audit net;
3905 #endif
3906 #if IS_ENABLED(CONFIG_IPV6)
3907 struct sockaddr_in6 sadd;
3908 int proto;
3909
3910 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3911 family = PF_INET;
3912 #endif /* CONFIG_IPV6 */
3913
3914 switch (family) {
3915 case PF_INET:
3916 /*
3917 * If there is a secmark use it rather than the CIPSO label.
3918 * If there is no secmark fall back to CIPSO.
3919 * The secmark is assumed to reflect policy better.
3920 */
3921 skp = smack_from_skb(skb);
3922 if (skp == NULL) {
3923 skp = smack_from_netlbl(sk, family, skb);
3924 if (skp == NULL)
3925 skp = smack_net_ambient;
3926 }
3927
3928 #ifdef CONFIG_AUDIT
3929 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3930 ad.a.u.net->family = family;
3931 ad.a.u.net->netif = skb->skb_iif;
3932 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3933 #endif
3934 /*
3935 * Receiving a packet requires that the other end
3936 * be able to write here. Read access is not required.
3937 * This is the simplist possible security model
3938 * for networking.
3939 */
3940 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3941 rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
3942 MAY_WRITE, rc);
3943 if (rc != 0)
3944 netlbl_skbuff_err(skb, family, rc, 0);
3945 break;
3946 #if IS_ENABLED(CONFIG_IPV6)
3947 case PF_INET6:
3948 proto = smk_skb_to_addr_ipv6(skb, &sadd);
3949 if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
3950 proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
3951 break;
3952 #ifdef SMACK_IPV6_SECMARK_LABELING
3953 skp = smack_from_skb(skb);
3954 if (skp == NULL) {
3955 if (smk_ipv6_localhost(&sadd))
3956 break;
3957 skp = smack_ipv6host_label(&sadd);
3958 if (skp == NULL)
3959 skp = smack_net_ambient;
3960 }
3961 #ifdef CONFIG_AUDIT
3962 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3963 ad.a.u.net->family = family;
3964 ad.a.u.net->netif = skb->skb_iif;
3965 ipv6_skb_to_auditdata(skb, &ad.a, NULL);
3966 #endif /* CONFIG_AUDIT */
3967 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3968 rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
3969 MAY_WRITE, rc);
3970 #endif /* SMACK_IPV6_SECMARK_LABELING */
3971 #ifdef SMACK_IPV6_PORT_LABELING
3972 rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
3973 #endif /* SMACK_IPV6_PORT_LABELING */
3974 if (rc != 0)
3975 icmpv6_send(skb, ICMPV6_DEST_UNREACH,
3976 ICMPV6_ADM_PROHIBITED, 0);
3977 break;
3978 #endif /* CONFIG_IPV6 */
3979 }
3980
3981 return rc;
3982 }
3983
3984 /**
3985 * smack_socket_getpeersec_stream - pull in packet label
3986 * @sock: the socket
3987 * @optval: user's destination
3988 * @optlen: size thereof
3989 * @len: max thereof
3990 *
3991 * returns zero on success, an error code otherwise
3992 */
smack_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned len)3993 static int smack_socket_getpeersec_stream(struct socket *sock,
3994 char __user *optval,
3995 int __user *optlen, unsigned len)
3996 {
3997 struct socket_smack *ssp;
3998 char *rcp = "";
3999 int slen = 1;
4000 int rc = 0;
4001
4002 ssp = sock->sk->sk_security;
4003 if (ssp->smk_packet != NULL) {
4004 rcp = ssp->smk_packet->smk_known;
4005 slen = strlen(rcp) + 1;
4006 }
4007
4008 if (slen > len)
4009 rc = -ERANGE;
4010 else if (copy_to_user(optval, rcp, slen) != 0)
4011 rc = -EFAULT;
4012
4013 if (put_user(slen, optlen) != 0)
4014 rc = -EFAULT;
4015
4016 return rc;
4017 }
4018
4019
4020 /**
4021 * smack_socket_getpeersec_dgram - pull in packet label
4022 * @sock: the peer socket
4023 * @skb: packet data
4024 * @secid: pointer to where to put the secid of the packet
4025 *
4026 * Sets the netlabel socket state on sk from parent
4027 */
smack_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)4028 static int smack_socket_getpeersec_dgram(struct socket *sock,
4029 struct sk_buff *skb, u32 *secid)
4030
4031 {
4032 struct socket_smack *ssp = NULL;
4033 struct smack_known *skp;
4034 struct sock *sk = NULL;
4035 int family = PF_UNSPEC;
4036 u32 s = 0; /* 0 is the invalid secid */
4037
4038 if (skb != NULL) {
4039 if (skb->protocol == htons(ETH_P_IP))
4040 family = PF_INET;
4041 #if IS_ENABLED(CONFIG_IPV6)
4042 else if (skb->protocol == htons(ETH_P_IPV6))
4043 family = PF_INET6;
4044 #endif /* CONFIG_IPV6 */
4045 }
4046 if (family == PF_UNSPEC && sock != NULL)
4047 family = sock->sk->sk_family;
4048
4049 switch (family) {
4050 case PF_UNIX:
4051 ssp = sock->sk->sk_security;
4052 s = ssp->smk_out->smk_secid;
4053 break;
4054 case PF_INET:
4055 skp = smack_from_skb(skb);
4056 if (skp) {
4057 s = skp->smk_secid;
4058 break;
4059 }
4060 /*
4061 * Translate what netlabel gave us.
4062 */
4063 if (sock != NULL)
4064 sk = sock->sk;
4065 skp = smack_from_netlbl(sk, family, skb);
4066 if (skp != NULL)
4067 s = skp->smk_secid;
4068 break;
4069 case PF_INET6:
4070 #ifdef SMACK_IPV6_SECMARK_LABELING
4071 skp = smack_from_skb(skb);
4072 if (skp)
4073 s = skp->smk_secid;
4074 #endif
4075 break;
4076 }
4077 *secid = s;
4078 if (s == 0)
4079 return -EINVAL;
4080 return 0;
4081 }
4082
4083 /**
4084 * smack_sock_graft - Initialize a newly created socket with an existing sock
4085 * @sk: child sock
4086 * @parent: parent socket
4087 *
4088 * Set the smk_{in,out} state of an existing sock based on the process that
4089 * is creating the new socket.
4090 */
smack_sock_graft(struct sock * sk,struct socket * parent)4091 static void smack_sock_graft(struct sock *sk, struct socket *parent)
4092 {
4093 struct socket_smack *ssp;
4094 struct smack_known *skp = smk_of_current();
4095
4096 if (sk == NULL ||
4097 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4098 return;
4099
4100 ssp = sk->sk_security;
4101 ssp->smk_in = skp;
4102 ssp->smk_out = skp;
4103 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
4104 }
4105
4106 /**
4107 * smack_inet_conn_request - Smack access check on connect
4108 * @sk: socket involved
4109 * @skb: packet
4110 * @req: unused
4111 *
4112 * Returns 0 if a task with the packet label could write to
4113 * the socket, otherwise an error code
4114 */
smack_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)4115 static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
4116 struct request_sock *req)
4117 {
4118 u16 family = sk->sk_family;
4119 struct smack_known *skp;
4120 struct socket_smack *ssp = sk->sk_security;
4121 struct sockaddr_in addr;
4122 struct iphdr *hdr;
4123 struct smack_known *hskp;
4124 int rc;
4125 struct smk_audit_info ad;
4126 #ifdef CONFIG_AUDIT
4127 struct lsm_network_audit net;
4128 #endif
4129
4130 #if IS_ENABLED(CONFIG_IPV6)
4131 if (family == PF_INET6) {
4132 /*
4133 * Handle mapped IPv4 packets arriving
4134 * via IPv6 sockets. Don't set up netlabel
4135 * processing on IPv6.
4136 */
4137 if (skb->protocol == htons(ETH_P_IP))
4138 family = PF_INET;
4139 else
4140 return 0;
4141 }
4142 #endif /* CONFIG_IPV6 */
4143
4144 /*
4145 * If there is a secmark use it rather than the CIPSO label.
4146 * If there is no secmark fall back to CIPSO.
4147 * The secmark is assumed to reflect policy better.
4148 */
4149 skp = smack_from_skb(skb);
4150 if (skp == NULL) {
4151 skp = smack_from_netlbl(sk, family, skb);
4152 if (skp == NULL)
4153 skp = &smack_known_huh;
4154 }
4155
4156 #ifdef CONFIG_AUDIT
4157 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4158 ad.a.u.net->family = family;
4159 ad.a.u.net->netif = skb->skb_iif;
4160 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4161 #endif
4162 /*
4163 * Receiving a packet requires that the other end be able to write
4164 * here. Read access is not required.
4165 */
4166 rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4167 rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4168 if (rc != 0)
4169 return rc;
4170
4171 /*
4172 * Save the peer's label in the request_sock so we can later setup
4173 * smk_packet in the child socket so that SO_PEERCRED can report it.
4174 */
4175 req->peer_secid = skp->smk_secid;
4176
4177 /*
4178 * We need to decide if we want to label the incoming connection here
4179 * if we do we only need to label the request_sock and the stack will
4180 * propagate the wire-label to the sock when it is created.
4181 */
4182 hdr = ip_hdr(skb);
4183 addr.sin_addr.s_addr = hdr->saddr;
4184 rcu_read_lock();
4185 hskp = smack_ipv4host_label(&addr);
4186 rcu_read_unlock();
4187
4188 if (hskp == NULL)
4189 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4190 else
4191 netlbl_req_delattr(req);
4192
4193 return rc;
4194 }
4195
4196 /**
4197 * smack_inet_csk_clone - Copy the connection information to the new socket
4198 * @sk: the new socket
4199 * @req: the connection's request_sock
4200 *
4201 * Transfer the connection's peer label to the newly created socket.
4202 */
smack_inet_csk_clone(struct sock * sk,const struct request_sock * req)4203 static void smack_inet_csk_clone(struct sock *sk,
4204 const struct request_sock *req)
4205 {
4206 struct socket_smack *ssp = sk->sk_security;
4207 struct smack_known *skp;
4208
4209 if (req->peer_secid != 0) {
4210 skp = smack_from_secid(req->peer_secid);
4211 ssp->smk_packet = skp;
4212 } else
4213 ssp->smk_packet = NULL;
4214 }
4215
4216 /*
4217 * Key management security hooks
4218 *
4219 * Casey has not tested key support very heavily.
4220 * The permission check is most likely too restrictive.
4221 * If you care about keys please have a look.
4222 */
4223 #ifdef CONFIG_KEYS
4224
4225 /**
4226 * smack_key_alloc - Set the key security blob
4227 * @key: object
4228 * @cred: the credentials to use
4229 * @flags: unused
4230 *
4231 * No allocation required
4232 *
4233 * Returns 0
4234 */
smack_key_alloc(struct key * key,const struct cred * cred,unsigned long flags)4235 static int smack_key_alloc(struct key *key, const struct cred *cred,
4236 unsigned long flags)
4237 {
4238 struct smack_known *skp = smk_of_task(smack_cred(cred));
4239
4240 key->security = skp;
4241 return 0;
4242 }
4243
4244 /**
4245 * smack_key_free - Clear the key security blob
4246 * @key: the object
4247 *
4248 * Clear the blob pointer
4249 */
smack_key_free(struct key * key)4250 static void smack_key_free(struct key *key)
4251 {
4252 key->security = NULL;
4253 }
4254
4255 /**
4256 * smack_key_permission - Smack access on a key
4257 * @key_ref: gets to the object
4258 * @cred: the credentials to use
4259 * @need_perm: requested key permission
4260 *
4261 * Return 0 if the task has read and write to the object,
4262 * an error code otherwise
4263 */
smack_key_permission(key_ref_t key_ref,const struct cred * cred,enum key_need_perm need_perm)4264 static int smack_key_permission(key_ref_t key_ref,
4265 const struct cred *cred,
4266 enum key_need_perm need_perm)
4267 {
4268 struct key *keyp;
4269 struct smk_audit_info ad;
4270 struct smack_known *tkp = smk_of_task(smack_cred(cred));
4271 int request = 0;
4272 int rc;
4273
4274 /*
4275 * Validate requested permissions
4276 */
4277 switch (need_perm) {
4278 case KEY_NEED_READ:
4279 case KEY_NEED_SEARCH:
4280 case KEY_NEED_VIEW:
4281 request |= MAY_READ;
4282 break;
4283 case KEY_NEED_WRITE:
4284 case KEY_NEED_LINK:
4285 case KEY_NEED_SETATTR:
4286 request |= MAY_WRITE;
4287 break;
4288 case KEY_NEED_UNSPECIFIED:
4289 case KEY_NEED_UNLINK:
4290 case KEY_SYSADMIN_OVERRIDE:
4291 case KEY_AUTHTOKEN_OVERRIDE:
4292 case KEY_DEFER_PERM_CHECK:
4293 return 0;
4294 default:
4295 return -EINVAL;
4296 }
4297
4298 keyp = key_ref_to_ptr(key_ref);
4299 if (keyp == NULL)
4300 return -EINVAL;
4301 /*
4302 * If the key hasn't been initialized give it access so that
4303 * it may do so.
4304 */
4305 if (keyp->security == NULL)
4306 return 0;
4307 /*
4308 * This should not occur
4309 */
4310 if (tkp == NULL)
4311 return -EACCES;
4312
4313 if (smack_privileged(CAP_MAC_OVERRIDE))
4314 return 0;
4315
4316 #ifdef CONFIG_AUDIT
4317 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4318 ad.a.u.key_struct.key = keyp->serial;
4319 ad.a.u.key_struct.key_desc = keyp->description;
4320 #endif
4321 rc = smk_access(tkp, keyp->security, request, &ad);
4322 rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4323 return rc;
4324 }
4325
4326 /*
4327 * smack_key_getsecurity - Smack label tagging the key
4328 * @key points to the key to be queried
4329 * @_buffer points to a pointer that should be set to point to the
4330 * resulting string (if no label or an error occurs).
4331 * Return the length of the string (including terminating NUL) or -ve if
4332 * an error.
4333 * May also return 0 (and a NULL buffer pointer) if there is no label.
4334 */
smack_key_getsecurity(struct key * key,char ** _buffer)4335 static int smack_key_getsecurity(struct key *key, char **_buffer)
4336 {
4337 struct smack_known *skp = key->security;
4338 size_t length;
4339 char *copy;
4340
4341 if (key->security == NULL) {
4342 *_buffer = NULL;
4343 return 0;
4344 }
4345
4346 copy = kstrdup(skp->smk_known, GFP_KERNEL);
4347 if (copy == NULL)
4348 return -ENOMEM;
4349 length = strlen(copy) + 1;
4350
4351 *_buffer = copy;
4352 return length;
4353 }
4354
4355
4356 #ifdef CONFIG_KEY_NOTIFICATIONS
4357 /**
4358 * smack_watch_key - Smack access to watch a key for notifications.
4359 * @key: The key to be watched
4360 *
4361 * Return 0 if the @watch->cred has permission to read from the key object and
4362 * an error otherwise.
4363 */
smack_watch_key(struct key * key)4364 static int smack_watch_key(struct key *key)
4365 {
4366 struct smk_audit_info ad;
4367 struct smack_known *tkp = smk_of_current();
4368 int rc;
4369
4370 if (key == NULL)
4371 return -EINVAL;
4372 /*
4373 * If the key hasn't been initialized give it access so that
4374 * it may do so.
4375 */
4376 if (key->security == NULL)
4377 return 0;
4378 /*
4379 * This should not occur
4380 */
4381 if (tkp == NULL)
4382 return -EACCES;
4383
4384 if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4385 return 0;
4386
4387 #ifdef CONFIG_AUDIT
4388 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4389 ad.a.u.key_struct.key = key->serial;
4390 ad.a.u.key_struct.key_desc = key->description;
4391 #endif
4392 rc = smk_access(tkp, key->security, MAY_READ, &ad);
4393 rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
4394 return rc;
4395 }
4396 #endif /* CONFIG_KEY_NOTIFICATIONS */
4397 #endif /* CONFIG_KEYS */
4398
4399 #ifdef CONFIG_WATCH_QUEUE
4400 /**
4401 * smack_post_notification - Smack access to post a notification to a queue
4402 * @w_cred: The credentials of the watcher.
4403 * @cred: The credentials of the event source (may be NULL).
4404 * @n: The notification message to be posted.
4405 */
smack_post_notification(const struct cred * w_cred,const struct cred * cred,struct watch_notification * n)4406 static int smack_post_notification(const struct cred *w_cred,
4407 const struct cred *cred,
4408 struct watch_notification *n)
4409 {
4410 struct smk_audit_info ad;
4411 struct smack_known *subj, *obj;
4412 int rc;
4413
4414 /* Always let maintenance notifications through. */
4415 if (n->type == WATCH_TYPE_META)
4416 return 0;
4417
4418 if (!cred)
4419 return 0;
4420 subj = smk_of_task(smack_cred(cred));
4421 obj = smk_of_task(smack_cred(w_cred));
4422
4423 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
4424 rc = smk_access(subj, obj, MAY_WRITE, &ad);
4425 rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
4426 return rc;
4427 }
4428 #endif /* CONFIG_WATCH_QUEUE */
4429
4430 /*
4431 * Smack Audit hooks
4432 *
4433 * Audit requires a unique representation of each Smack specific
4434 * rule. This unique representation is used to distinguish the
4435 * object to be audited from remaining kernel objects and also
4436 * works as a glue between the audit hooks.
4437 *
4438 * Since repository entries are added but never deleted, we'll use
4439 * the smack_known label address related to the given audit rule as
4440 * the needed unique representation. This also better fits the smack
4441 * model where nearly everything is a label.
4442 */
4443 #ifdef CONFIG_AUDIT
4444
4445 /**
4446 * smack_audit_rule_init - Initialize a smack audit rule
4447 * @field: audit rule fields given from user-space (audit.h)
4448 * @op: required testing operator (=, !=, >, <, ...)
4449 * @rulestr: smack label to be audited
4450 * @vrule: pointer to save our own audit rule representation
4451 *
4452 * Prepare to audit cases where (@field @op @rulestr) is true.
4453 * The label to be audited is created if necessay.
4454 */
smack_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)4455 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4456 {
4457 struct smack_known *skp;
4458 char **rule = (char **)vrule;
4459 *rule = NULL;
4460
4461 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4462 return -EINVAL;
4463
4464 if (op != Audit_equal && op != Audit_not_equal)
4465 return -EINVAL;
4466
4467 skp = smk_import_entry(rulestr, 0);
4468 if (IS_ERR(skp))
4469 return PTR_ERR(skp);
4470
4471 *rule = skp->smk_known;
4472
4473 return 0;
4474 }
4475
4476 /**
4477 * smack_audit_rule_known - Distinguish Smack audit rules
4478 * @krule: rule of interest, in Audit kernel representation format
4479 *
4480 * This is used to filter Smack rules from remaining Audit ones.
4481 * If it's proved that this rule belongs to us, the
4482 * audit_rule_match hook will be called to do the final judgement.
4483 */
smack_audit_rule_known(struct audit_krule * krule)4484 static int smack_audit_rule_known(struct audit_krule *krule)
4485 {
4486 struct audit_field *f;
4487 int i;
4488
4489 for (i = 0; i < krule->field_count; i++) {
4490 f = &krule->fields[i];
4491
4492 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4493 return 1;
4494 }
4495
4496 return 0;
4497 }
4498
4499 /**
4500 * smack_audit_rule_match - Audit given object ?
4501 * @secid: security id for identifying the object to test
4502 * @field: audit rule flags given from user-space
4503 * @op: required testing operator
4504 * @vrule: smack internal rule presentation
4505 *
4506 * The core Audit hook. It's used to take the decision of
4507 * whether to audit or not to audit a given object.
4508 */
smack_audit_rule_match(u32 secid,u32 field,u32 op,void * vrule)4509 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4510 {
4511 struct smack_known *skp;
4512 char *rule = vrule;
4513
4514 if (unlikely(!rule)) {
4515 WARN_ONCE(1, "Smack: missing rule\n");
4516 return -ENOENT;
4517 }
4518
4519 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4520 return 0;
4521
4522 skp = smack_from_secid(secid);
4523
4524 /*
4525 * No need to do string comparisons. If a match occurs,
4526 * both pointers will point to the same smack_known
4527 * label.
4528 */
4529 if (op == Audit_equal)
4530 return (rule == skp->smk_known);
4531 if (op == Audit_not_equal)
4532 return (rule != skp->smk_known);
4533
4534 return 0;
4535 }
4536
4537 /*
4538 * There is no need for a smack_audit_rule_free hook.
4539 * No memory was allocated.
4540 */
4541
4542 #endif /* CONFIG_AUDIT */
4543
4544 /**
4545 * smack_ismaclabel - check if xattr @name references a smack MAC label
4546 * @name: Full xattr name to check.
4547 */
smack_ismaclabel(const char * name)4548 static int smack_ismaclabel(const char *name)
4549 {
4550 return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4551 }
4552
4553
4554 /**
4555 * smack_secid_to_secctx - return the smack label for a secid
4556 * @secid: incoming integer
4557 * @secdata: destination
4558 * @seclen: how long it is
4559 *
4560 * Exists for networking code.
4561 */
smack_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)4562 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4563 {
4564 struct smack_known *skp = smack_from_secid(secid);
4565
4566 if (secdata)
4567 *secdata = skp->smk_known;
4568 *seclen = strlen(skp->smk_known);
4569 return 0;
4570 }
4571
4572 /**
4573 * smack_secctx_to_secid - return the secid for a smack label
4574 * @secdata: smack label
4575 * @seclen: how long result is
4576 * @secid: outgoing integer
4577 *
4578 * Exists for audit and networking code.
4579 */
smack_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)4580 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4581 {
4582 struct smack_known *skp = smk_find_entry(secdata);
4583
4584 if (skp)
4585 *secid = skp->smk_secid;
4586 else
4587 *secid = 0;
4588 return 0;
4589 }
4590
4591 /*
4592 * There used to be a smack_release_secctx hook
4593 * that did nothing back when hooks were in a vector.
4594 * Now that there's a list such a hook adds cost.
4595 */
4596
smack_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)4597 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4598 {
4599 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
4600 ctxlen, 0);
4601 }
4602
smack_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)4603 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4604 {
4605 return __vfs_setxattr_noperm(&init_user_ns, dentry, XATTR_NAME_SMACK,
4606 ctx, ctxlen, 0);
4607 }
4608
smack_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)4609 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4610 {
4611 struct smack_known *skp = smk_of_inode(inode);
4612
4613 *ctx = skp->smk_known;
4614 *ctxlen = strlen(skp->smk_known);
4615 return 0;
4616 }
4617
smack_inode_copy_up(struct dentry * dentry,struct cred ** new)4618 static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
4619 {
4620
4621 struct task_smack *tsp;
4622 struct smack_known *skp;
4623 struct inode_smack *isp;
4624 struct cred *new_creds = *new;
4625
4626 if (new_creds == NULL) {
4627 new_creds = prepare_creds();
4628 if (new_creds == NULL)
4629 return -ENOMEM;
4630 }
4631
4632 tsp = smack_cred(new_creds);
4633
4634 /*
4635 * Get label from overlay inode and set it in create_sid
4636 */
4637 isp = smack_inode(d_inode(dentry->d_parent));
4638 skp = isp->smk_inode;
4639 tsp->smk_task = skp;
4640 *new = new_creds;
4641 return 0;
4642 }
4643
smack_inode_copy_up_xattr(const char * name)4644 static int smack_inode_copy_up_xattr(const char *name)
4645 {
4646 /*
4647 * Return 1 if this is the smack access Smack attribute.
4648 */
4649 if (strcmp(name, XATTR_NAME_SMACK) == 0)
4650 return 1;
4651
4652 return -EOPNOTSUPP;
4653 }
4654
smack_dentry_create_files_as(struct dentry * dentry,int mode,struct qstr * name,const struct cred * old,struct cred * new)4655 static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
4656 struct qstr *name,
4657 const struct cred *old,
4658 struct cred *new)
4659 {
4660 struct task_smack *otsp = smack_cred(old);
4661 struct task_smack *ntsp = smack_cred(new);
4662 struct inode_smack *isp;
4663 int may;
4664
4665 /*
4666 * Use the process credential unless all of
4667 * the transmuting criteria are met
4668 */
4669 ntsp->smk_task = otsp->smk_task;
4670
4671 /*
4672 * the attribute of the containing directory
4673 */
4674 isp = smack_inode(d_inode(dentry->d_parent));
4675
4676 if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
4677 rcu_read_lock();
4678 may = smk_access_entry(otsp->smk_task->smk_known,
4679 isp->smk_inode->smk_known,
4680 &otsp->smk_task->smk_rules);
4681 rcu_read_unlock();
4682
4683 /*
4684 * If the directory is transmuting and the rule
4685 * providing access is transmuting use the containing
4686 * directory label instead of the process label.
4687 */
4688 if (may > 0 && (may & MAY_TRANSMUTE))
4689 ntsp->smk_task = isp->smk_inode;
4690 }
4691 return 0;
4692 }
4693
4694 struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
4695 .lbs_cred = sizeof(struct task_smack),
4696 .lbs_file = sizeof(struct smack_known *),
4697 .lbs_inode = sizeof(struct inode_smack),
4698 .lbs_ipc = sizeof(struct smack_known *),
4699 .lbs_msg_msg = sizeof(struct smack_known *),
4700 .lbs_superblock = sizeof(struct superblock_smack),
4701 };
4702
4703 static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
4704 LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
4705 LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
4706 LSM_HOOK_INIT(syslog, smack_syslog),
4707
4708 LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
4709 LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
4710
4711 LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
4712 LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
4713 LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
4714 LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
4715 LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
4716
4717 LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
4718
4719 LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
4720 LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
4721 LSM_HOOK_INIT(inode_link, smack_inode_link),
4722 LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
4723 LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
4724 LSM_HOOK_INIT(inode_rename, smack_inode_rename),
4725 LSM_HOOK_INIT(inode_permission, smack_inode_permission),
4726 LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
4727 LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
4728 LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
4729 LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
4730 LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
4731 LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
4732 LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
4733 LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
4734 LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
4735 LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
4736
4737 LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
4738 LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
4739 LSM_HOOK_INIT(file_lock, smack_file_lock),
4740 LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
4741 LSM_HOOK_INIT(mmap_file, smack_mmap_file),
4742 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
4743 LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
4744 LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
4745 LSM_HOOK_INIT(file_receive, smack_file_receive),
4746
4747 LSM_HOOK_INIT(file_open, smack_file_open),
4748
4749 LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
4750 LSM_HOOK_INIT(cred_free, smack_cred_free),
4751 LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
4752 LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
4753 LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
4754 LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
4755 LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
4756 LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
4757 LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
4758 LSM_HOOK_INIT(task_getsid, smack_task_getsid),
4759 LSM_HOOK_INIT(task_getsecid_subj, smack_task_getsecid_subj),
4760 LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
4761 LSM_HOOK_INIT(task_setnice, smack_task_setnice),
4762 LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
4763 LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
4764 LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
4765 LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
4766 LSM_HOOK_INIT(task_movememory, smack_task_movememory),
4767 LSM_HOOK_INIT(task_kill, smack_task_kill),
4768 LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
4769
4770 LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
4771 LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
4772
4773 LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
4774
4775 LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
4776 LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
4777 LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
4778 LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
4779 LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
4780
4781 LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
4782 LSM_HOOK_INIT(shm_associate, smack_shm_associate),
4783 LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
4784 LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
4785
4786 LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
4787 LSM_HOOK_INIT(sem_associate, smack_sem_associate),
4788 LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
4789 LSM_HOOK_INIT(sem_semop, smack_sem_semop),
4790
4791 LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
4792
4793 LSM_HOOK_INIT(getprocattr, smack_getprocattr),
4794 LSM_HOOK_INIT(setprocattr, smack_setprocattr),
4795
4796 LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
4797 LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
4798
4799 LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
4800 LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
4801 #ifdef SMACK_IPV6_PORT_LABELING
4802 LSM_HOOK_INIT(socket_bind, smack_socket_bind),
4803 #endif
4804 LSM_HOOK_INIT(socket_connect, smack_socket_connect),
4805 LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
4806 LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
4807 LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
4808 LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
4809 LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
4810 LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
4811 LSM_HOOK_INIT(sock_graft, smack_sock_graft),
4812 LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
4813 LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
4814
4815 /* key management security hooks */
4816 #ifdef CONFIG_KEYS
4817 LSM_HOOK_INIT(key_alloc, smack_key_alloc),
4818 LSM_HOOK_INIT(key_free, smack_key_free),
4819 LSM_HOOK_INIT(key_permission, smack_key_permission),
4820 LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
4821 #ifdef CONFIG_KEY_NOTIFICATIONS
4822 LSM_HOOK_INIT(watch_key, smack_watch_key),
4823 #endif
4824 #endif /* CONFIG_KEYS */
4825
4826 #ifdef CONFIG_WATCH_QUEUE
4827 LSM_HOOK_INIT(post_notification, smack_post_notification),
4828 #endif
4829
4830 /* Audit hooks */
4831 #ifdef CONFIG_AUDIT
4832 LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
4833 LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
4834 LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
4835 #endif /* CONFIG_AUDIT */
4836
4837 LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
4838 LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
4839 LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
4840 LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
4841 LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
4842 LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
4843 LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
4844 LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
4845 LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
4846 };
4847
4848
init_smack_known_list(void)4849 static __init void init_smack_known_list(void)
4850 {
4851 /*
4852 * Initialize rule list locks
4853 */
4854 mutex_init(&smack_known_huh.smk_rules_lock);
4855 mutex_init(&smack_known_hat.smk_rules_lock);
4856 mutex_init(&smack_known_floor.smk_rules_lock);
4857 mutex_init(&smack_known_star.smk_rules_lock);
4858 mutex_init(&smack_known_web.smk_rules_lock);
4859 /*
4860 * Initialize rule lists
4861 */
4862 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
4863 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
4864 INIT_LIST_HEAD(&smack_known_star.smk_rules);
4865 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
4866 INIT_LIST_HEAD(&smack_known_web.smk_rules);
4867 /*
4868 * Create the known labels list
4869 */
4870 smk_insert_entry(&smack_known_huh);
4871 smk_insert_entry(&smack_known_hat);
4872 smk_insert_entry(&smack_known_star);
4873 smk_insert_entry(&smack_known_floor);
4874 smk_insert_entry(&smack_known_web);
4875 }
4876
4877 /**
4878 * smack_init - initialize the smack system
4879 *
4880 * Returns 0 on success, -ENOMEM is there's no memory
4881 */
smack_init(void)4882 static __init int smack_init(void)
4883 {
4884 struct cred *cred = (struct cred *) current->cred;
4885 struct task_smack *tsp;
4886
4887 smack_rule_cache = KMEM_CACHE(smack_rule, 0);
4888 if (!smack_rule_cache)
4889 return -ENOMEM;
4890
4891 /*
4892 * Set the security state for the initial task.
4893 */
4894 tsp = smack_cred(cred);
4895 init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
4896
4897 /*
4898 * Register with LSM
4899 */
4900 security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
4901 smack_enabled = 1;
4902
4903 pr_info("Smack: Initializing.\n");
4904 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
4905 pr_info("Smack: Netfilter enabled.\n");
4906 #endif
4907 #ifdef SMACK_IPV6_PORT_LABELING
4908 pr_info("Smack: IPv6 port labeling enabled.\n");
4909 #endif
4910 #ifdef SMACK_IPV6_SECMARK_LABELING
4911 pr_info("Smack: IPv6 Netfilter enabled.\n");
4912 #endif
4913
4914 /* initialize the smack_known_list */
4915 init_smack_known_list();
4916
4917 return 0;
4918 }
4919
4920 /*
4921 * Smack requires early initialization in order to label
4922 * all processes and objects when they are created.
4923 */
4924 DEFINE_LSM(smack) = {
4925 .name = "smack",
4926 .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
4927 .blobs = &smack_blob_sizes,
4928 .init = smack_init,
4929 };
4930