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