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LSM: shrink the common_audit_data data union
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1 /*
2 * Simplified MAC Kernel (smack) security module
3 *
4 * This file contains the smack hook function implementations.
5 *
6 * Authors:
7 * Casey Schaufler <casey@schaufler-ca.com>
8 * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
9 *
10 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
11 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12 * Paul Moore <paul@paul-moore.com>
13 * Copyright (C) 2010 Nokia Corporation
14 * Copyright (C) 2011 Intel Corporation.
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
21 #include <linux/xattr.h>
22 #include <linux/pagemap.h>
23 #include <linux/mount.h>
24 #include <linux/stat.h>
25 #include <linux/kd.h>
26 #include <asm/ioctls.h>
27 #include <linux/ip.h>
28 #include <linux/tcp.h>
29 #include <linux/udp.h>
30 #include <linux/slab.h>
31 #include <linux/mutex.h>
32 #include <linux/pipe_fs_i.h>
33 #include <net/netlabel.h>
34 #include <net/cipso_ipv4.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 "smack.h"
43
44 #define task_security(task) (task_cred_xxx((task), security))
45
46 #define TRANS_TRUE "TRUE"
47 #define TRANS_TRUE_SIZE 4
48
49 /**
50 * smk_fetch - Fetch the smack label from a file.
51 * @ip: a pointer to the inode
52 * @dp: a pointer to the dentry
53 *
54 * Returns a pointer to the master list entry for the Smack label
55 * or NULL if there was no label to fetch.
56 */
57 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
58 {
59 int rc;
60 char in[SMK_LABELLEN];
61
62 if (ip->i_op->getxattr == NULL)
63 return NULL;
64
65 rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
66 if (rc < 0)
67 return NULL;
68
69 return smk_import(in, rc);
70 }
71
72 /**
73 * new_inode_smack - allocate an inode security blob
74 * @smack: a pointer to the Smack label to use in the blob
75 *
76 * Returns the new blob or NULL if there's no memory available
77 */
78 struct inode_smack *new_inode_smack(char *smack)
79 {
80 struct inode_smack *isp;
81
82 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
83 if (isp == NULL)
84 return NULL;
85
86 isp->smk_inode = smack;
87 isp->smk_flags = 0;
88 mutex_init(&isp->smk_lock);
89
90 return isp;
91 }
92
93 /**
94 * new_task_smack - allocate a task security blob
95 * @smack: a pointer to the Smack label to use in the blob
96 *
97 * Returns the new blob or NULL if there's no memory available
98 */
99 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
100 {
101 struct task_smack *tsp;
102
103 tsp = kzalloc(sizeof(struct task_smack), gfp);
104 if (tsp == NULL)
105 return NULL;
106
107 tsp->smk_task = task;
108 tsp->smk_forked = forked;
109 INIT_LIST_HEAD(&tsp->smk_rules);
110 mutex_init(&tsp->smk_rules_lock);
111
112 return tsp;
113 }
114
115 /**
116 * smk_copy_rules - copy a rule set
117 * @nhead - new rules header pointer
118 * @ohead - old rules header pointer
119 *
120 * Returns 0 on success, -ENOMEM on error
121 */
122 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
123 gfp_t gfp)
124 {
125 struct smack_rule *nrp;
126 struct smack_rule *orp;
127 int rc = 0;
128
129 INIT_LIST_HEAD(nhead);
130
131 list_for_each_entry_rcu(orp, ohead, list) {
132 nrp = kzalloc(sizeof(struct smack_rule), gfp);
133 if (nrp == NULL) {
134 rc = -ENOMEM;
135 break;
136 }
137 *nrp = *orp;
138 list_add_rcu(&nrp->list, nhead);
139 }
140 return rc;
141 }
142
143 /*
144 * LSM hooks.
145 * We he, that is fun!
146 */
147
148 /**
149 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
150 * @ctp: child task pointer
151 * @mode: ptrace attachment mode
152 *
153 * Returns 0 if access is OK, an error code otherwise
154 *
155 * Do the capability checks, and require read and write.
156 */
157 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
158 {
159 int rc;
160 struct smk_audit_info ad;
161 char *tsp;
162
163 rc = cap_ptrace_access_check(ctp, mode);
164 if (rc != 0)
165 return rc;
166
167 tsp = smk_of_task(task_security(ctp));
168 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
169 smk_ad_setfield_u_tsk(&ad, ctp);
170
171 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
172 return rc;
173 }
174
175 /**
176 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
177 * @ptp: parent task pointer
178 *
179 * Returns 0 if access is OK, an error code otherwise
180 *
181 * Do the capability checks, and require read and write.
182 */
183 static int smack_ptrace_traceme(struct task_struct *ptp)
184 {
185 int rc;
186 struct smk_audit_info ad;
187 char *tsp;
188
189 rc = cap_ptrace_traceme(ptp);
190 if (rc != 0)
191 return rc;
192
193 tsp = smk_of_task(task_security(ptp));
194 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
195 smk_ad_setfield_u_tsk(&ad, ptp);
196
197 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
198 return rc;
199 }
200
201 /**
202 * smack_syslog - Smack approval on syslog
203 * @type: message type
204 *
205 * Require that the task has the floor label
206 *
207 * Returns 0 on success, error code otherwise.
208 */
209 static int smack_syslog(int typefrom_file)
210 {
211 int rc = 0;
212 char *sp = smk_of_current();
213
214 if (capable(CAP_MAC_OVERRIDE))
215 return 0;
216
217 if (sp != smack_known_floor.smk_known)
218 rc = -EACCES;
219
220 return rc;
221 }
222
223
224 /*
225 * Superblock Hooks.
226 */
227
228 /**
229 * smack_sb_alloc_security - allocate a superblock blob
230 * @sb: the superblock getting the blob
231 *
232 * Returns 0 on success or -ENOMEM on error.
233 */
234 static int smack_sb_alloc_security(struct super_block *sb)
235 {
236 struct superblock_smack *sbsp;
237
238 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
239
240 if (sbsp == NULL)
241 return -ENOMEM;
242
243 sbsp->smk_root = smack_known_floor.smk_known;
244 sbsp->smk_default = smack_known_floor.smk_known;
245 sbsp->smk_floor = smack_known_floor.smk_known;
246 sbsp->smk_hat = smack_known_hat.smk_known;
247 sbsp->smk_initialized = 0;
248 spin_lock_init(&sbsp->smk_sblock);
249
250 sb->s_security = sbsp;
251
252 return 0;
253 }
254
255 /**
256 * smack_sb_free_security - free a superblock blob
257 * @sb: the superblock getting the blob
258 *
259 */
260 static void smack_sb_free_security(struct super_block *sb)
261 {
262 kfree(sb->s_security);
263 sb->s_security = NULL;
264 }
265
266 /**
267 * smack_sb_copy_data - copy mount options data for processing
268 * @orig: where to start
269 * @smackopts: mount options string
270 *
271 * Returns 0 on success or -ENOMEM on error.
272 *
273 * Copy the Smack specific mount options out of the mount
274 * options list.
275 */
276 static int smack_sb_copy_data(char *orig, char *smackopts)
277 {
278 char *cp, *commap, *otheropts, *dp;
279
280 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
281 if (otheropts == NULL)
282 return -ENOMEM;
283
284 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
285 if (strstr(cp, SMK_FSDEFAULT) == cp)
286 dp = smackopts;
287 else if (strstr(cp, SMK_FSFLOOR) == cp)
288 dp = smackopts;
289 else if (strstr(cp, SMK_FSHAT) == cp)
290 dp = smackopts;
291 else if (strstr(cp, SMK_FSROOT) == cp)
292 dp = smackopts;
293 else
294 dp = otheropts;
295
296 commap = strchr(cp, ',');
297 if (commap != NULL)
298 *commap = '\0';
299
300 if (*dp != '\0')
301 strcat(dp, ",");
302 strcat(dp, cp);
303 }
304
305 strcpy(orig, otheropts);
306 free_page((unsigned long)otheropts);
307
308 return 0;
309 }
310
311 /**
312 * smack_sb_kern_mount - Smack specific mount processing
313 * @sb: the file system superblock
314 * @flags: the mount flags
315 * @data: the smack mount options
316 *
317 * Returns 0 on success, an error code on failure
318 */
319 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
320 {
321 struct dentry *root = sb->s_root;
322 struct inode *inode = root->d_inode;
323 struct superblock_smack *sp = sb->s_security;
324 struct inode_smack *isp;
325 char *op;
326 char *commap;
327 char *nsp;
328
329 spin_lock(&sp->smk_sblock);
330 if (sp->smk_initialized != 0) {
331 spin_unlock(&sp->smk_sblock);
332 return 0;
333 }
334 sp->smk_initialized = 1;
335 spin_unlock(&sp->smk_sblock);
336
337 for (op = data; op != NULL; op = commap) {
338 commap = strchr(op, ',');
339 if (commap != NULL)
340 *commap++ = '\0';
341
342 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
343 op += strlen(SMK_FSHAT);
344 nsp = smk_import(op, 0);
345 if (nsp != NULL)
346 sp->smk_hat = nsp;
347 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
348 op += strlen(SMK_FSFLOOR);
349 nsp = smk_import(op, 0);
350 if (nsp != NULL)
351 sp->smk_floor = nsp;
352 } else if (strncmp(op, SMK_FSDEFAULT,
353 strlen(SMK_FSDEFAULT)) == 0) {
354 op += strlen(SMK_FSDEFAULT);
355 nsp = smk_import(op, 0);
356 if (nsp != NULL)
357 sp->smk_default = nsp;
358 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
359 op += strlen(SMK_FSROOT);
360 nsp = smk_import(op, 0);
361 if (nsp != NULL)
362 sp->smk_root = nsp;
363 }
364 }
365
366 /*
367 * Initialize the root inode.
368 */
369 isp = inode->i_security;
370 if (isp == NULL)
371 inode->i_security = new_inode_smack(sp->smk_root);
372 else
373 isp->smk_inode = sp->smk_root;
374
375 return 0;
376 }
377
378 /**
379 * smack_sb_statfs - Smack check on statfs
380 * @dentry: identifies the file system in question
381 *
382 * Returns 0 if current can read the floor of the filesystem,
383 * and error code otherwise
384 */
385 static int smack_sb_statfs(struct dentry *dentry)
386 {
387 struct superblock_smack *sbp = dentry->d_sb->s_security;
388 int rc;
389 struct smk_audit_info ad;
390
391 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
392 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
393
394 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
395 return rc;
396 }
397
398 /**
399 * smack_sb_mount - Smack check for mounting
400 * @dev_name: unused
401 * @path: mount point
402 * @type: unused
403 * @flags: unused
404 * @data: unused
405 *
406 * Returns 0 if current can write the floor of the filesystem
407 * being mounted on, an error code otherwise.
408 */
409 static int smack_sb_mount(char *dev_name, struct path *path,
410 char *type, unsigned long flags, void *data)
411 {
412 struct superblock_smack *sbp = path->dentry->d_sb->s_security;
413 struct smk_audit_info ad;
414
415 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
416 smk_ad_setfield_u_fs_path(&ad, *path);
417
418 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
419 }
420
421 /**
422 * smack_sb_umount - Smack check for unmounting
423 * @mnt: file system to unmount
424 * @flags: unused
425 *
426 * Returns 0 if current can write the floor of the filesystem
427 * being unmounted, an error code otherwise.
428 */
429 static int smack_sb_umount(struct vfsmount *mnt, int flags)
430 {
431 struct superblock_smack *sbp;
432 struct smk_audit_info ad;
433 struct path path;
434
435 path.dentry = mnt->mnt_root;
436 path.mnt = mnt;
437
438 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
439 smk_ad_setfield_u_fs_path(&ad, path);
440
441 sbp = path.dentry->d_sb->s_security;
442 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
443 }
444
445 /*
446 * BPRM hooks
447 */
448
449 /**
450 * smack_bprm_set_creds - set creds for exec
451 * @bprm: the exec information
452 *
453 * Returns 0 if it gets a blob, -ENOMEM otherwise
454 */
455 static int smack_bprm_set_creds(struct linux_binprm *bprm)
456 {
457 struct inode *inode = bprm->file->f_path.dentry->d_inode;
458 struct task_smack *bsp = bprm->cred->security;
459 struct inode_smack *isp;
460 int rc;
461
462 rc = cap_bprm_set_creds(bprm);
463 if (rc != 0)
464 return rc;
465
466 if (bprm->cred_prepared)
467 return 0;
468
469 isp = inode->i_security;
470 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
471 return 0;
472
473 if (bprm->unsafe)
474 return -EPERM;
475
476 bsp->smk_task = isp->smk_task;
477 bprm->per_clear |= PER_CLEAR_ON_SETID;
478
479 return 0;
480 }
481
482 /**
483 * smack_bprm_committing_creds - Prepare to install the new credentials
484 * from bprm.
485 *
486 * @bprm: binprm for exec
487 */
488 static void smack_bprm_committing_creds(struct linux_binprm *bprm)
489 {
490 struct task_smack *bsp = bprm->cred->security;
491
492 if (bsp->smk_task != bsp->smk_forked)
493 current->pdeath_signal = 0;
494 }
495
496 /**
497 * smack_bprm_secureexec - Return the decision to use secureexec.
498 * @bprm: binprm for exec
499 *
500 * Returns 0 on success.
501 */
502 static int smack_bprm_secureexec(struct linux_binprm *bprm)
503 {
504 struct task_smack *tsp = current_security();
505 int ret = cap_bprm_secureexec(bprm);
506
507 if (!ret && (tsp->smk_task != tsp->smk_forked))
508 ret = 1;
509
510 return ret;
511 }
512
513 /*
514 * Inode hooks
515 */
516
517 /**
518 * smack_inode_alloc_security - allocate an inode blob
519 * @inode: the inode in need of a blob
520 *
521 * Returns 0 if it gets a blob, -ENOMEM otherwise
522 */
523 static int smack_inode_alloc_security(struct inode *inode)
524 {
525 inode->i_security = new_inode_smack(smk_of_current());
526 if (inode->i_security == NULL)
527 return -ENOMEM;
528 return 0;
529 }
530
531 /**
532 * smack_inode_free_security - free an inode blob
533 * @inode: the inode with a blob
534 *
535 * Clears the blob pointer in inode
536 */
537 static void smack_inode_free_security(struct inode *inode)
538 {
539 kfree(inode->i_security);
540 inode->i_security = NULL;
541 }
542
543 /**
544 * smack_inode_init_security - copy out the smack from an inode
545 * @inode: the inode
546 * @dir: unused
547 * @qstr: unused
548 * @name: where to put the attribute name
549 * @value: where to put the attribute value
550 * @len: where to put the length of the attribute
551 *
552 * Returns 0 if it all works out, -ENOMEM if there's no memory
553 */
554 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
555 const struct qstr *qstr, char **name,
556 void **value, size_t *len)
557 {
558 struct smack_known *skp;
559 char *csp = smk_of_current();
560 char *isp = smk_of_inode(inode);
561 char *dsp = smk_of_inode(dir);
562 int may;
563
564 if (name) {
565 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
566 if (*name == NULL)
567 return -ENOMEM;
568 }
569
570 if (value) {
571 skp = smk_find_entry(csp);
572 rcu_read_lock();
573 may = smk_access_entry(csp, dsp, &skp->smk_rules);
574 rcu_read_unlock();
575
576 /*
577 * If the access rule allows transmutation and
578 * the directory requests transmutation then
579 * by all means transmute.
580 */
581 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
582 smk_inode_transmutable(dir))
583 isp = dsp;
584
585 *value = kstrdup(isp, GFP_KERNEL);
586 if (*value == NULL)
587 return -ENOMEM;
588 }
589
590 if (len)
591 *len = strlen(isp) + 1;
592
593 return 0;
594 }
595
596 /**
597 * smack_inode_link - Smack check on link
598 * @old_dentry: the existing object
599 * @dir: unused
600 * @new_dentry: the new object
601 *
602 * Returns 0 if access is permitted, an error code otherwise
603 */
604 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
605 struct dentry *new_dentry)
606 {
607 char *isp;
608 struct smk_audit_info ad;
609 int rc;
610
611 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
612 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
613
614 isp = smk_of_inode(old_dentry->d_inode);
615 rc = smk_curacc(isp, MAY_WRITE, &ad);
616
617 if (rc == 0 && new_dentry->d_inode != NULL) {
618 isp = smk_of_inode(new_dentry->d_inode);
619 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
620 rc = smk_curacc(isp, MAY_WRITE, &ad);
621 }
622
623 return rc;
624 }
625
626 /**
627 * smack_inode_unlink - Smack check on inode deletion
628 * @dir: containing directory object
629 * @dentry: file to unlink
630 *
631 * Returns 0 if current can write the containing directory
632 * and the object, error code otherwise
633 */
634 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
635 {
636 struct inode *ip = dentry->d_inode;
637 struct smk_audit_info ad;
638 int rc;
639
640 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
641 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
642
643 /*
644 * You need write access to the thing you're unlinking
645 */
646 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
647 if (rc == 0) {
648 /*
649 * You also need write access to the containing directory
650 */
651 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
652 smk_ad_setfield_u_fs_inode(&ad, dir);
653 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
654 }
655 return rc;
656 }
657
658 /**
659 * smack_inode_rmdir - Smack check on directory deletion
660 * @dir: containing directory object
661 * @dentry: directory to unlink
662 *
663 * Returns 0 if current can write the containing directory
664 * and the directory, error code otherwise
665 */
666 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
667 {
668 struct smk_audit_info ad;
669 int rc;
670
671 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
672 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
673
674 /*
675 * You need write access to the thing you're removing
676 */
677 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
678 if (rc == 0) {
679 /*
680 * You also need write access to the containing directory
681 */
682 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
683 smk_ad_setfield_u_fs_inode(&ad, dir);
684 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
685 }
686
687 return rc;
688 }
689
690 /**
691 * smack_inode_rename - Smack check on rename
692 * @old_inode: the old directory
693 * @old_dentry: unused
694 * @new_inode: the new directory
695 * @new_dentry: unused
696 *
697 * Read and write access is required on both the old and
698 * new directories.
699 *
700 * Returns 0 if access is permitted, an error code otherwise
701 */
702 static int smack_inode_rename(struct inode *old_inode,
703 struct dentry *old_dentry,
704 struct inode *new_inode,
705 struct dentry *new_dentry)
706 {
707 int rc;
708 char *isp;
709 struct smk_audit_info ad;
710
711 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
712 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
713
714 isp = smk_of_inode(old_dentry->d_inode);
715 rc = smk_curacc(isp, MAY_READWRITE, &ad);
716
717 if (rc == 0 && new_dentry->d_inode != NULL) {
718 isp = smk_of_inode(new_dentry->d_inode);
719 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
720 rc = smk_curacc(isp, MAY_READWRITE, &ad);
721 }
722 return rc;
723 }
724
725 /**
726 * smack_inode_permission - Smack version of permission()
727 * @inode: the inode in question
728 * @mask: the access requested
729 *
730 * This is the important Smack hook.
731 *
732 * Returns 0 if access is permitted, -EACCES otherwise
733 */
734 static int smack_inode_permission(struct inode *inode, int mask)
735 {
736 struct smk_audit_info ad;
737 int no_block = mask & MAY_NOT_BLOCK;
738
739 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
740 /*
741 * No permission to check. Existence test. Yup, it's there.
742 */
743 if (mask == 0)
744 return 0;
745
746 /* May be droppable after audit */
747 if (no_block)
748 return -ECHILD;
749 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
750 smk_ad_setfield_u_fs_inode(&ad, inode);
751 return smk_curacc(smk_of_inode(inode), mask, &ad);
752 }
753
754 /**
755 * smack_inode_setattr - Smack check for setting attributes
756 * @dentry: the object
757 * @iattr: for the force flag
758 *
759 * Returns 0 if access is permitted, an error code otherwise
760 */
761 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
762 {
763 struct smk_audit_info ad;
764 /*
765 * Need to allow for clearing the setuid bit.
766 */
767 if (iattr->ia_valid & ATTR_FORCE)
768 return 0;
769 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
770 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
771
772 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
773 }
774
775 /**
776 * smack_inode_getattr - Smack check for getting attributes
777 * @mnt: unused
778 * @dentry: the object
779 *
780 * Returns 0 if access is permitted, an error code otherwise
781 */
782 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
783 {
784 struct smk_audit_info ad;
785 struct path path;
786
787 path.dentry = dentry;
788 path.mnt = mnt;
789
790 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
791 smk_ad_setfield_u_fs_path(&ad, path);
792 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
793 }
794
795 /**
796 * smack_inode_setxattr - Smack check for setting xattrs
797 * @dentry: the object
798 * @name: name of the attribute
799 * @value: unused
800 * @size: unused
801 * @flags: unused
802 *
803 * This protects the Smack attribute explicitly.
804 *
805 * Returns 0 if access is permitted, an error code otherwise
806 */
807 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
808 const void *value, size_t size, int flags)
809 {
810 struct smk_audit_info ad;
811 int rc = 0;
812
813 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
814 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
815 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
816 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
817 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
818 if (!capable(CAP_MAC_ADMIN))
819 rc = -EPERM;
820 /*
821 * check label validity here so import wont fail on
822 * post_setxattr
823 */
824 if (size == 0 || size >= SMK_LABELLEN ||
825 smk_import(value, size) == NULL)
826 rc = -EINVAL;
827 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
828 if (!capable(CAP_MAC_ADMIN))
829 rc = -EPERM;
830 if (size != TRANS_TRUE_SIZE ||
831 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
832 rc = -EINVAL;
833 } else
834 rc = cap_inode_setxattr(dentry, name, value, size, flags);
835
836 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
837 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
838
839 if (rc == 0)
840 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
841
842 return rc;
843 }
844
845 /**
846 * smack_inode_post_setxattr - Apply the Smack update approved above
847 * @dentry: object
848 * @name: attribute name
849 * @value: attribute value
850 * @size: attribute size
851 * @flags: unused
852 *
853 * Set the pointer in the inode blob to the entry found
854 * in the master label list.
855 */
856 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
857 const void *value, size_t size, int flags)
858 {
859 char *nsp;
860 struct inode_smack *isp = dentry->d_inode->i_security;
861
862 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
863 nsp = smk_import(value, size);
864 if (nsp != NULL)
865 isp->smk_inode = nsp;
866 else
867 isp->smk_inode = smack_known_invalid.smk_known;
868 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
869 nsp = smk_import(value, size);
870 if (nsp != NULL)
871 isp->smk_task = nsp;
872 else
873 isp->smk_task = smack_known_invalid.smk_known;
874 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
875 nsp = smk_import(value, size);
876 if (nsp != NULL)
877 isp->smk_mmap = nsp;
878 else
879 isp->smk_mmap = smack_known_invalid.smk_known;
880 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
881 isp->smk_flags |= SMK_INODE_TRANSMUTE;
882
883 return;
884 }
885
886 /**
887 * smack_inode_getxattr - Smack check on getxattr
888 * @dentry: the object
889 * @name: unused
890 *
891 * Returns 0 if access is permitted, an error code otherwise
892 */
893 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
894 {
895 struct smk_audit_info ad;
896
897 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
898 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
899
900 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
901 }
902
903 /**
904 * smack_inode_removexattr - Smack check on removexattr
905 * @dentry: the object
906 * @name: name of the attribute
907 *
908 * Removing the Smack attribute requires CAP_MAC_ADMIN
909 *
910 * Returns 0 if access is permitted, an error code otherwise
911 */
912 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
913 {
914 struct inode_smack *isp;
915 struct smk_audit_info ad;
916 int rc = 0;
917
918 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
919 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
920 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
921 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
922 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
923 strcmp(name, XATTR_NAME_SMACKMMAP)) {
924 if (!capable(CAP_MAC_ADMIN))
925 rc = -EPERM;
926 } else
927 rc = cap_inode_removexattr(dentry, name);
928
929 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
930 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
931 if (rc == 0)
932 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
933
934 if (rc == 0) {
935 isp = dentry->d_inode->i_security;
936 isp->smk_task = NULL;
937 isp->smk_mmap = NULL;
938 }
939
940 return rc;
941 }
942
943 /**
944 * smack_inode_getsecurity - get smack xattrs
945 * @inode: the object
946 * @name: attribute name
947 * @buffer: where to put the result
948 * @alloc: unused
949 *
950 * Returns the size of the attribute or an error code
951 */
952 static int smack_inode_getsecurity(const struct inode *inode,
953 const char *name, void **buffer,
954 bool alloc)
955 {
956 struct socket_smack *ssp;
957 struct socket *sock;
958 struct super_block *sbp;
959 struct inode *ip = (struct inode *)inode;
960 char *isp;
961 int ilen;
962 int rc = 0;
963
964 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
965 isp = smk_of_inode(inode);
966 ilen = strlen(isp) + 1;
967 *buffer = isp;
968 return ilen;
969 }
970
971 /*
972 * The rest of the Smack xattrs are only on sockets.
973 */
974 sbp = ip->i_sb;
975 if (sbp->s_magic != SOCKFS_MAGIC)
976 return -EOPNOTSUPP;
977
978 sock = SOCKET_I(ip);
979 if (sock == NULL || sock->sk == NULL)
980 return -EOPNOTSUPP;
981
982 ssp = sock->sk->sk_security;
983
984 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
985 isp = ssp->smk_in;
986 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
987 isp = ssp->smk_out;
988 else
989 return -EOPNOTSUPP;
990
991 ilen = strlen(isp) + 1;
992 if (rc == 0) {
993 *buffer = isp;
994 rc = ilen;
995 }
996
997 return rc;
998 }
999
1000
1001 /**
1002 * smack_inode_listsecurity - list the Smack attributes
1003 * @inode: the object
1004 * @buffer: where they go
1005 * @buffer_size: size of buffer
1006 *
1007 * Returns 0 on success, -EINVAL otherwise
1008 */
1009 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1010 size_t buffer_size)
1011 {
1012 int len = strlen(XATTR_NAME_SMACK);
1013
1014 if (buffer != NULL && len <= buffer_size) {
1015 memcpy(buffer, XATTR_NAME_SMACK, len);
1016 return len;
1017 }
1018 return -EINVAL;
1019 }
1020
1021 /**
1022 * smack_inode_getsecid - Extract inode's security id
1023 * @inode: inode to extract the info from
1024 * @secid: where result will be saved
1025 */
1026 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1027 {
1028 struct inode_smack *isp = inode->i_security;
1029
1030 *secid = smack_to_secid(isp->smk_inode);
1031 }
1032
1033 /*
1034 * File Hooks
1035 */
1036
1037 /**
1038 * smack_file_permission - Smack check on file operations
1039 * @file: unused
1040 * @mask: unused
1041 *
1042 * Returns 0
1043 *
1044 * Should access checks be done on each read or write?
1045 * UNICOS and SELinux say yes.
1046 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1047 *
1048 * I'll say no for now. Smack does not do the frequent
1049 * label changing that SELinux does.
1050 */
1051 static int smack_file_permission(struct file *file, int mask)
1052 {
1053 return 0;
1054 }
1055
1056 /**
1057 * smack_file_alloc_security - assign a file security blob
1058 * @file: the object
1059 *
1060 * The security blob for a file is a pointer to the master
1061 * label list, so no allocation is done.
1062 *
1063 * Returns 0
1064 */
1065 static int smack_file_alloc_security(struct file *file)
1066 {
1067 file->f_security = smk_of_current();
1068 return 0;
1069 }
1070
1071 /**
1072 * smack_file_free_security - clear a file security blob
1073 * @file: the object
1074 *
1075 * The security blob for a file is a pointer to the master
1076 * label list, so no memory is freed.
1077 */
1078 static void smack_file_free_security(struct file *file)
1079 {
1080 file->f_security = NULL;
1081 }
1082
1083 /**
1084 * smack_file_ioctl - Smack check on ioctls
1085 * @file: the object
1086 * @cmd: what to do
1087 * @arg: unused
1088 *
1089 * Relies heavily on the correct use of the ioctl command conventions.
1090 *
1091 * Returns 0 if allowed, error code otherwise
1092 */
1093 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1094 unsigned long arg)
1095 {
1096 int rc = 0;
1097 struct smk_audit_info ad;
1098
1099 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1100 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1101
1102 if (_IOC_DIR(cmd) & _IOC_WRITE)
1103 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1104
1105 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1106 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1107
1108 return rc;
1109 }
1110
1111 /**
1112 * smack_file_lock - Smack check on file locking
1113 * @file: the object
1114 * @cmd: unused
1115 *
1116 * Returns 0 if current has write access, error code otherwise
1117 */
1118 static int smack_file_lock(struct file *file, unsigned int cmd)
1119 {
1120 struct smk_audit_info ad;
1121
1122 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1123 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1124 return smk_curacc(file->f_security, MAY_WRITE, &ad);
1125 }
1126
1127 /**
1128 * smack_file_fcntl - Smack check on fcntl
1129 * @file: the object
1130 * @cmd: what action to check
1131 * @arg: unused
1132 *
1133 * Generally these operations are harmless.
1134 * File locking operations present an obvious mechanism
1135 * for passing information, so they require write access.
1136 *
1137 * Returns 0 if current has access, error code otherwise
1138 */
1139 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1140 unsigned long arg)
1141 {
1142 struct smk_audit_info ad;
1143 int rc = 0;
1144
1145
1146 switch (cmd) {
1147 case F_GETLK:
1148 case F_SETLK:
1149 case F_SETLKW:
1150 case F_SETOWN:
1151 case F_SETSIG:
1152 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1153 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1154 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1155 break;
1156 default:
1157 break;
1158 }
1159
1160 return rc;
1161 }
1162
1163 /**
1164 * smack_file_mmap :
1165 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1166 * if mapping anonymous memory.
1167 * @file contains the file structure for file to map (may be NULL).
1168 * @reqprot contains the protection requested by the application.
1169 * @prot contains the protection that will be applied by the kernel.
1170 * @flags contains the operational flags.
1171 * Return 0 if permission is granted.
1172 */
1173 static int smack_file_mmap(struct file *file,
1174 unsigned long reqprot, unsigned long prot,
1175 unsigned long flags, unsigned long addr,
1176 unsigned long addr_only)
1177 {
1178 struct smack_known *skp;
1179 struct smack_rule *srp;
1180 struct task_smack *tsp;
1181 char *sp;
1182 char *msmack;
1183 char *osmack;
1184 struct inode_smack *isp;
1185 struct dentry *dp;
1186 int may;
1187 int mmay;
1188 int tmay;
1189 int rc;
1190
1191 /* do DAC check on address space usage */
1192 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1193 if (rc || addr_only)
1194 return rc;
1195
1196 if (file == NULL || file->f_dentry == NULL)
1197 return 0;
1198
1199 dp = file->f_dentry;
1200
1201 if (dp->d_inode == NULL)
1202 return 0;
1203
1204 isp = dp->d_inode->i_security;
1205 if (isp->smk_mmap == NULL)
1206 return 0;
1207 msmack = isp->smk_mmap;
1208
1209 tsp = current_security();
1210 sp = smk_of_current();
1211 skp = smk_find_entry(sp);
1212 rc = 0;
1213
1214 rcu_read_lock();
1215 /*
1216 * For each Smack rule associated with the subject
1217 * label verify that the SMACK64MMAP also has access
1218 * to that rule's object label.
1219 */
1220 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1221 osmack = srp->smk_object;
1222 /*
1223 * Matching labels always allows access.
1224 */
1225 if (msmack == osmack)
1226 continue;
1227 /*
1228 * If there is a matching local rule take
1229 * that into account as well.
1230 */
1231 may = smk_access_entry(srp->smk_subject, osmack,
1232 &tsp->smk_rules);
1233 if (may == -ENOENT)
1234 may = srp->smk_access;
1235 else
1236 may &= srp->smk_access;
1237 /*
1238 * If may is zero the SMACK64MMAP subject can't
1239 * possibly have less access.
1240 */
1241 if (may == 0)
1242 continue;
1243
1244 /*
1245 * Fetch the global list entry.
1246 * If there isn't one a SMACK64MMAP subject
1247 * can't have as much access as current.
1248 */
1249 skp = smk_find_entry(msmack);
1250 mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
1251 if (mmay == -ENOENT) {
1252 rc = -EACCES;
1253 break;
1254 }
1255 /*
1256 * If there is a local entry it modifies the
1257 * potential access, too.
1258 */
1259 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1260 if (tmay != -ENOENT)
1261 mmay &= tmay;
1262
1263 /*
1264 * If there is any access available to current that is
1265 * not available to a SMACK64MMAP subject
1266 * deny access.
1267 */
1268 if ((may | mmay) != mmay) {
1269 rc = -EACCES;
1270 break;
1271 }
1272 }
1273
1274 rcu_read_unlock();
1275
1276 return rc;
1277 }
1278
1279 /**
1280 * smack_file_set_fowner - set the file security blob value
1281 * @file: object in question
1282 *
1283 * Returns 0
1284 * Further research may be required on this one.
1285 */
1286 static int smack_file_set_fowner(struct file *file)
1287 {
1288 file->f_security = smk_of_current();
1289 return 0;
1290 }
1291
1292 /**
1293 * smack_file_send_sigiotask - Smack on sigio
1294 * @tsk: The target task
1295 * @fown: the object the signal come from
1296 * @signum: unused
1297 *
1298 * Allow a privileged task to get signals even if it shouldn't
1299 *
1300 * Returns 0 if a subject with the object's smack could
1301 * write to the task, an error code otherwise.
1302 */
1303 static int smack_file_send_sigiotask(struct task_struct *tsk,
1304 struct fown_struct *fown, int signum)
1305 {
1306 struct file *file;
1307 int rc;
1308 char *tsp = smk_of_task(tsk->cred->security);
1309 struct smk_audit_info ad;
1310
1311 /*
1312 * struct fown_struct is never outside the context of a struct file
1313 */
1314 file = container_of(fown, struct file, f_owner);
1315
1316 /* we don't log here as rc can be overriden */
1317 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1318 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1319 rc = 0;
1320
1321 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1322 smk_ad_setfield_u_tsk(&ad, tsk);
1323 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1324 return rc;
1325 }
1326
1327 /**
1328 * smack_file_receive - Smack file receive check
1329 * @file: the object
1330 *
1331 * Returns 0 if current has access, error code otherwise
1332 */
1333 static int smack_file_receive(struct file *file)
1334 {
1335 int may = 0;
1336 struct smk_audit_info ad;
1337
1338 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1339 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1340 /*
1341 * This code relies on bitmasks.
1342 */
1343 if (file->f_mode & FMODE_READ)
1344 may = MAY_READ;
1345 if (file->f_mode & FMODE_WRITE)
1346 may |= MAY_WRITE;
1347
1348 return smk_curacc(file->f_security, may, &ad);
1349 }
1350
1351 /**
1352 * smack_dentry_open - Smack dentry open processing
1353 * @file: the object
1354 * @cred: unused
1355 *
1356 * Set the security blob in the file structure.
1357 *
1358 * Returns 0
1359 */
1360 static int smack_dentry_open(struct file *file, const struct cred *cred)
1361 {
1362 struct inode_smack *isp = file->f_path.dentry->d_inode->i_security;
1363
1364 file->f_security = isp->smk_inode;
1365
1366 return 0;
1367 }
1368
1369 /*
1370 * Task hooks
1371 */
1372
1373 /**
1374 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1375 * @new: the new credentials
1376 * @gfp: the atomicity of any memory allocations
1377 *
1378 * Prepare a blank set of credentials for modification. This must allocate all
1379 * the memory the LSM module might require such that cred_transfer() can
1380 * complete without error.
1381 */
1382 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1383 {
1384 struct task_smack *tsp;
1385
1386 tsp = new_task_smack(NULL, NULL, gfp);
1387 if (tsp == NULL)
1388 return -ENOMEM;
1389
1390 cred->security = tsp;
1391
1392 return 0;
1393 }
1394
1395
1396 /**
1397 * smack_cred_free - "free" task-level security credentials
1398 * @cred: the credentials in question
1399 *
1400 */
1401 static void smack_cred_free(struct cred *cred)
1402 {
1403 struct task_smack *tsp = cred->security;
1404 struct smack_rule *rp;
1405 struct list_head *l;
1406 struct list_head *n;
1407
1408 if (tsp == NULL)
1409 return;
1410 cred->security = NULL;
1411
1412 list_for_each_safe(l, n, &tsp->smk_rules) {
1413 rp = list_entry(l, struct smack_rule, list);
1414 list_del(&rp->list);
1415 kfree(rp);
1416 }
1417 kfree(tsp);
1418 }
1419
1420 /**
1421 * smack_cred_prepare - prepare new set of credentials for modification
1422 * @new: the new credentials
1423 * @old: the original credentials
1424 * @gfp: the atomicity of any memory allocations
1425 *
1426 * Prepare a new set of credentials for modification.
1427 */
1428 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1429 gfp_t gfp)
1430 {
1431 struct task_smack *old_tsp = old->security;
1432 struct task_smack *new_tsp;
1433 int rc;
1434
1435 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1436 if (new_tsp == NULL)
1437 return -ENOMEM;
1438
1439 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1440 if (rc != 0)
1441 return rc;
1442
1443 new->security = new_tsp;
1444 return 0;
1445 }
1446
1447 /**
1448 * smack_cred_transfer - Transfer the old credentials to the new credentials
1449 * @new: the new credentials
1450 * @old: the original credentials
1451 *
1452 * Fill in a set of blank credentials from another set of credentials.
1453 */
1454 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1455 {
1456 struct task_smack *old_tsp = old->security;
1457 struct task_smack *new_tsp = new->security;
1458
1459 new_tsp->smk_task = old_tsp->smk_task;
1460 new_tsp->smk_forked = old_tsp->smk_task;
1461 mutex_init(&new_tsp->smk_rules_lock);
1462 INIT_LIST_HEAD(&new_tsp->smk_rules);
1463
1464
1465 /* cbs copy rule list */
1466 }
1467
1468 /**
1469 * smack_kernel_act_as - Set the subjective context in a set of credentials
1470 * @new: points to the set of credentials to be modified.
1471 * @secid: specifies the security ID to be set
1472 *
1473 * Set the security data for a kernel service.
1474 */
1475 static int smack_kernel_act_as(struct cred *new, u32 secid)
1476 {
1477 struct task_smack *new_tsp = new->security;
1478 char *smack = smack_from_secid(secid);
1479
1480 if (smack == NULL)
1481 return -EINVAL;
1482
1483 new_tsp->smk_task = smack;
1484 return 0;
1485 }
1486
1487 /**
1488 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1489 * @new: points to the set of credentials to be modified
1490 * @inode: points to the inode to use as a reference
1491 *
1492 * Set the file creation context in a set of credentials to the same
1493 * as the objective context of the specified inode
1494 */
1495 static int smack_kernel_create_files_as(struct cred *new,
1496 struct inode *inode)
1497 {
1498 struct inode_smack *isp = inode->i_security;
1499 struct task_smack *tsp = new->security;
1500
1501 tsp->smk_forked = isp->smk_inode;
1502 tsp->smk_task = isp->smk_inode;
1503 return 0;
1504 }
1505
1506 /**
1507 * smk_curacc_on_task - helper to log task related access
1508 * @p: the task object
1509 * @access: the access requested
1510 * @caller: name of the calling function for audit
1511 *
1512 * Return 0 if access is permitted
1513 */
1514 static int smk_curacc_on_task(struct task_struct *p, int access,
1515 const char *caller)
1516 {
1517 struct smk_audit_info ad;
1518
1519 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1520 smk_ad_setfield_u_tsk(&ad, p);
1521 return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1522 }
1523
1524 /**
1525 * smack_task_setpgid - Smack check on setting pgid
1526 * @p: the task object
1527 * @pgid: unused
1528 *
1529 * Return 0 if write access is permitted
1530 */
1531 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1532 {
1533 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1534 }
1535
1536 /**
1537 * smack_task_getpgid - Smack access check for getpgid
1538 * @p: the object task
1539 *
1540 * Returns 0 if current can read the object task, error code otherwise
1541 */
1542 static int smack_task_getpgid(struct task_struct *p)
1543 {
1544 return smk_curacc_on_task(p, MAY_READ, __func__);
1545 }
1546
1547 /**
1548 * smack_task_getsid - Smack access check for getsid
1549 * @p: the object task
1550 *
1551 * Returns 0 if current can read the object task, error code otherwise
1552 */
1553 static int smack_task_getsid(struct task_struct *p)
1554 {
1555 return smk_curacc_on_task(p, MAY_READ, __func__);
1556 }
1557
1558 /**
1559 * smack_task_getsecid - get the secid of the task
1560 * @p: the object task
1561 * @secid: where to put the result
1562 *
1563 * Sets the secid to contain a u32 version of the smack label.
1564 */
1565 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1566 {
1567 *secid = smack_to_secid(smk_of_task(task_security(p)));
1568 }
1569
1570 /**
1571 * smack_task_setnice - Smack check on setting nice
1572 * @p: the task object
1573 * @nice: unused
1574 *
1575 * Return 0 if write access is permitted
1576 */
1577 static int smack_task_setnice(struct task_struct *p, int nice)
1578 {
1579 int rc;
1580
1581 rc = cap_task_setnice(p, nice);
1582 if (rc == 0)
1583 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1584 return rc;
1585 }
1586
1587 /**
1588 * smack_task_setioprio - Smack check on setting ioprio
1589 * @p: the task object
1590 * @ioprio: unused
1591 *
1592 * Return 0 if write access is permitted
1593 */
1594 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1595 {
1596 int rc;
1597
1598 rc = cap_task_setioprio(p, ioprio);
1599 if (rc == 0)
1600 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1601 return rc;
1602 }
1603
1604 /**
1605 * smack_task_getioprio - Smack check on reading ioprio
1606 * @p: the task object
1607 *
1608 * Return 0 if read access is permitted
1609 */
1610 static int smack_task_getioprio(struct task_struct *p)
1611 {
1612 return smk_curacc_on_task(p, MAY_READ, __func__);
1613 }
1614
1615 /**
1616 * smack_task_setscheduler - Smack check on setting scheduler
1617 * @p: the task object
1618 * @policy: unused
1619 * @lp: unused
1620 *
1621 * Return 0 if read access is permitted
1622 */
1623 static int smack_task_setscheduler(struct task_struct *p)
1624 {
1625 int rc;
1626
1627 rc = cap_task_setscheduler(p);
1628 if (rc == 0)
1629 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1630 return rc;
1631 }
1632
1633 /**
1634 * smack_task_getscheduler - Smack check on reading scheduler
1635 * @p: the task object
1636 *
1637 * Return 0 if read access is permitted
1638 */
1639 static int smack_task_getscheduler(struct task_struct *p)
1640 {
1641 return smk_curacc_on_task(p, MAY_READ, __func__);
1642 }
1643
1644 /**
1645 * smack_task_movememory - Smack check on moving memory
1646 * @p: the task object
1647 *
1648 * Return 0 if write access is permitted
1649 */
1650 static int smack_task_movememory(struct task_struct *p)
1651 {
1652 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1653 }
1654
1655 /**
1656 * smack_task_kill - Smack check on signal delivery
1657 * @p: the task object
1658 * @info: unused
1659 * @sig: unused
1660 * @secid: identifies the smack to use in lieu of current's
1661 *
1662 * Return 0 if write access is permitted
1663 *
1664 * The secid behavior is an artifact of an SELinux hack
1665 * in the USB code. Someday it may go away.
1666 */
1667 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1668 int sig, u32 secid)
1669 {
1670 struct smk_audit_info ad;
1671
1672 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1673 smk_ad_setfield_u_tsk(&ad, p);
1674 /*
1675 * Sending a signal requires that the sender
1676 * can write the receiver.
1677 */
1678 if (secid == 0)
1679 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1680 &ad);
1681 /*
1682 * If the secid isn't 0 we're dealing with some USB IO
1683 * specific behavior. This is not clean. For one thing
1684 * we can't take privilege into account.
1685 */
1686 return smk_access(smack_from_secid(secid),
1687 smk_of_task(task_security(p)), MAY_WRITE, &ad);
1688 }
1689
1690 /**
1691 * smack_task_wait - Smack access check for waiting
1692 * @p: task to wait for
1693 *
1694 * Returns 0 if current can wait for p, error code otherwise
1695 */
1696 static int smack_task_wait(struct task_struct *p)
1697 {
1698 struct smk_audit_info ad;
1699 char *sp = smk_of_current();
1700 char *tsp = smk_of_forked(task_security(p));
1701 int rc;
1702
1703 /* we don't log here, we can be overriden */
1704 rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1705 if (rc == 0)
1706 goto out_log;
1707
1708 /*
1709 * Allow the operation to succeed if either task
1710 * has privilege to perform operations that might
1711 * account for the smack labels having gotten to
1712 * be different in the first place.
1713 *
1714 * This breaks the strict subject/object access
1715 * control ideal, taking the object's privilege
1716 * state into account in the decision as well as
1717 * the smack value.
1718 */
1719 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1720 rc = 0;
1721 /* we log only if we didn't get overriden */
1722 out_log:
1723 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1724 smk_ad_setfield_u_tsk(&ad, p);
1725 smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1726 return rc;
1727 }
1728
1729 /**
1730 * smack_task_to_inode - copy task smack into the inode blob
1731 * @p: task to copy from
1732 * @inode: inode to copy to
1733 *
1734 * Sets the smack pointer in the inode security blob
1735 */
1736 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1737 {
1738 struct inode_smack *isp = inode->i_security;
1739 isp->smk_inode = smk_of_task(task_security(p));
1740 }
1741
1742 /*
1743 * Socket hooks.
1744 */
1745
1746 /**
1747 * smack_sk_alloc_security - Allocate a socket blob
1748 * @sk: the socket
1749 * @family: unused
1750 * @gfp_flags: memory allocation flags
1751 *
1752 * Assign Smack pointers to current
1753 *
1754 * Returns 0 on success, -ENOMEM is there's no memory
1755 */
1756 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1757 {
1758 char *csp = smk_of_current();
1759 struct socket_smack *ssp;
1760
1761 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1762 if (ssp == NULL)
1763 return -ENOMEM;
1764
1765 ssp->smk_in = csp;
1766 ssp->smk_out = csp;
1767 ssp->smk_packet = NULL;
1768
1769 sk->sk_security = ssp;
1770
1771 return 0;
1772 }
1773
1774 /**
1775 * smack_sk_free_security - Free a socket blob
1776 * @sk: the socket
1777 *
1778 * Clears the blob pointer
1779 */
1780 static void smack_sk_free_security(struct sock *sk)
1781 {
1782 kfree(sk->sk_security);
1783 }
1784
1785 /**
1786 * smack_host_label - check host based restrictions
1787 * @sip: the object end
1788 *
1789 * looks for host based access restrictions
1790 *
1791 * This version will only be appropriate for really small sets of single label
1792 * hosts. The caller is responsible for ensuring that the RCU read lock is
1793 * taken before calling this function.
1794 *
1795 * Returns the label of the far end or NULL if it's not special.
1796 */
1797 static char *smack_host_label(struct sockaddr_in *sip)
1798 {
1799 struct smk_netlbladdr *snp;
1800 struct in_addr *siap = &sip->sin_addr;
1801
1802 if (siap->s_addr == 0)
1803 return NULL;
1804
1805 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1806 /*
1807 * we break after finding the first match because
1808 * the list is sorted from longest to shortest mask
1809 * so we have found the most specific match
1810 */
1811 if ((&snp->smk_host.sin_addr)->s_addr ==
1812 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1813 /* we have found the special CIPSO option */
1814 if (snp->smk_label == smack_cipso_option)
1815 return NULL;
1816 return snp->smk_label;
1817 }
1818
1819 return NULL;
1820 }
1821
1822 /**
1823 * smack_set_catset - convert a capset to netlabel mls categories
1824 * @catset: the Smack categories
1825 * @sap: where to put the netlabel categories
1826 *
1827 * Allocates and fills attr.mls.cat
1828 */
1829 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1830 {
1831 unsigned char *cp;
1832 unsigned char m;
1833 int cat;
1834 int rc;
1835 int byte;
1836
1837 if (!catset)
1838 return;
1839
1840 sap->flags |= NETLBL_SECATTR_MLS_CAT;
1841 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1842 sap->attr.mls.cat->startbit = 0;
1843
1844 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1845 for (m = 0x80; m != 0; m >>= 1, cat++) {
1846 if ((m & *cp) == 0)
1847 continue;
1848 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1849 cat, GFP_ATOMIC);
1850 }
1851 }
1852
1853 /**
1854 * smack_to_secattr - fill a secattr from a smack value
1855 * @smack: the smack value
1856 * @nlsp: where the result goes
1857 *
1858 * Casey says that CIPSO is good enough for now.
1859 * It can be used to effect.
1860 * It can also be abused to effect when necessary.
1861 * Apologies to the TSIG group in general and GW in particular.
1862 */
1863 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1864 {
1865 struct smack_cipso cipso;
1866 int rc;
1867
1868 nlsp->domain = smack;
1869 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1870
1871 rc = smack_to_cipso(smack, &cipso);
1872 if (rc == 0) {
1873 nlsp->attr.mls.lvl = cipso.smk_level;
1874 smack_set_catset(cipso.smk_catset, nlsp);
1875 } else {
1876 nlsp->attr.mls.lvl = smack_cipso_direct;
1877 smack_set_catset(smack, nlsp);
1878 }
1879 }
1880
1881 /**
1882 * smack_netlabel - Set the secattr on a socket
1883 * @sk: the socket
1884 * @labeled: socket label scheme
1885 *
1886 * Convert the outbound smack value (smk_out) to a
1887 * secattr and attach it to the socket.
1888 *
1889 * Returns 0 on success or an error code
1890 */
1891 static int smack_netlabel(struct sock *sk, int labeled)
1892 {
1893 struct socket_smack *ssp = sk->sk_security;
1894 struct netlbl_lsm_secattr secattr;
1895 int rc = 0;
1896
1897 /*
1898 * Usually the netlabel code will handle changing the
1899 * packet labeling based on the label.
1900 * The case of a single label host is different, because
1901 * a single label host should never get a labeled packet
1902 * even though the label is usually associated with a packet
1903 * label.
1904 */
1905 local_bh_disable();
1906 bh_lock_sock_nested(sk);
1907
1908 if (ssp->smk_out == smack_net_ambient ||
1909 labeled == SMACK_UNLABELED_SOCKET)
1910 netlbl_sock_delattr(sk);
1911 else {
1912 netlbl_secattr_init(&secattr);
1913 smack_to_secattr(ssp->smk_out, &secattr);
1914 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1915 netlbl_secattr_destroy(&secattr);
1916 }
1917
1918 bh_unlock_sock(sk);
1919 local_bh_enable();
1920
1921 return rc;
1922 }
1923
1924 /**
1925 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1926 * @sk: the socket
1927 * @sap: the destination address
1928 *
1929 * Set the correct secattr for the given socket based on the destination
1930 * address and perform any outbound access checks needed.
1931 *
1932 * Returns 0 on success or an error code.
1933 *
1934 */
1935 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1936 {
1937 int rc;
1938 int sk_lbl;
1939 char *hostsp;
1940 struct socket_smack *ssp = sk->sk_security;
1941 struct smk_audit_info ad;
1942 struct lsm_network_audit net;
1943
1944 rcu_read_lock();
1945 hostsp = smack_host_label(sap);
1946 if (hostsp != NULL) {
1947 sk_lbl = SMACK_UNLABELED_SOCKET;
1948 #ifdef CONFIG_AUDIT
1949 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1950 ad.a.u.net->family = sap->sin_family;
1951 ad.a.u.net->dport = sap->sin_port;
1952 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1953 #endif
1954 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1955 } else {
1956 sk_lbl = SMACK_CIPSO_SOCKET;
1957 rc = 0;
1958 }
1959 rcu_read_unlock();
1960 if (rc != 0)
1961 return rc;
1962
1963 return smack_netlabel(sk, sk_lbl);
1964 }
1965
1966 /**
1967 * smack_inode_setsecurity - set smack xattrs
1968 * @inode: the object
1969 * @name: attribute name
1970 * @value: attribute value
1971 * @size: size of the attribute
1972 * @flags: unused
1973 *
1974 * Sets the named attribute in the appropriate blob
1975 *
1976 * Returns 0 on success, or an error code
1977 */
1978 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1979 const void *value, size_t size, int flags)
1980 {
1981 char *sp;
1982 struct inode_smack *nsp = inode->i_security;
1983 struct socket_smack *ssp;
1984 struct socket *sock;
1985 int rc = 0;
1986
1987 if (value == NULL || size > SMK_LABELLEN || size == 0)
1988 return -EACCES;
1989
1990 sp = smk_import(value, size);
1991 if (sp == NULL)
1992 return -EINVAL;
1993
1994 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1995 nsp->smk_inode = sp;
1996 nsp->smk_flags |= SMK_INODE_INSTANT;
1997 return 0;
1998 }
1999 /*
2000 * The rest of the Smack xattrs are only on sockets.
2001 */
2002 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2003 return -EOPNOTSUPP;
2004
2005 sock = SOCKET_I(inode);
2006 if (sock == NULL || sock->sk == NULL)
2007 return -EOPNOTSUPP;
2008
2009 ssp = sock->sk->sk_security;
2010
2011 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2012 ssp->smk_in = sp;
2013 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2014 ssp->smk_out = sp;
2015 if (sock->sk->sk_family != PF_UNIX) {
2016 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2017 if (rc != 0)
2018 printk(KERN_WARNING
2019 "Smack: \"%s\" netlbl error %d.\n",
2020 __func__, -rc);
2021 }
2022 } else
2023 return -EOPNOTSUPP;
2024
2025 return 0;
2026 }
2027
2028 /**
2029 * smack_socket_post_create - finish socket setup
2030 * @sock: the socket
2031 * @family: protocol family
2032 * @type: unused
2033 * @protocol: unused
2034 * @kern: unused
2035 *
2036 * Sets the netlabel information on the socket
2037 *
2038 * Returns 0 on success, and error code otherwise
2039 */
2040 static int smack_socket_post_create(struct socket *sock, int family,
2041 int type, int protocol, int kern)
2042 {
2043 if (family != PF_INET || sock->sk == NULL)
2044 return 0;
2045 /*
2046 * Set the outbound netlbl.
2047 */
2048 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2049 }
2050
2051 /**
2052 * smack_socket_connect - connect access check
2053 * @sock: the socket
2054 * @sap: the other end
2055 * @addrlen: size of sap
2056 *
2057 * Verifies that a connection may be possible
2058 *
2059 * Returns 0 on success, and error code otherwise
2060 */
2061 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2062 int addrlen)
2063 {
2064 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2065 return 0;
2066 if (addrlen < sizeof(struct sockaddr_in))
2067 return -EINVAL;
2068
2069 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2070 }
2071
2072 /**
2073 * smack_flags_to_may - convert S_ to MAY_ values
2074 * @flags: the S_ value
2075 *
2076 * Returns the equivalent MAY_ value
2077 */
2078 static int smack_flags_to_may(int flags)
2079 {
2080 int may = 0;
2081
2082 if (flags & S_IRUGO)
2083 may |= MAY_READ;
2084 if (flags & S_IWUGO)
2085 may |= MAY_WRITE;
2086 if (flags & S_IXUGO)
2087 may |= MAY_EXEC;
2088
2089 return may;
2090 }
2091
2092 /**
2093 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2094 * @msg: the object
2095 *
2096 * Returns 0
2097 */
2098 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2099 {
2100 msg->security = smk_of_current();
2101 return 0;
2102 }
2103
2104 /**
2105 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2106 * @msg: the object
2107 *
2108 * Clears the blob pointer
2109 */
2110 static void smack_msg_msg_free_security(struct msg_msg *msg)
2111 {
2112 msg->security = NULL;
2113 }
2114
2115 /**
2116 * smack_of_shm - the smack pointer for the shm
2117 * @shp: the object
2118 *
2119 * Returns a pointer to the smack value
2120 */
2121 static char *smack_of_shm(struct shmid_kernel *shp)
2122 {
2123 return (char *)shp->shm_perm.security;
2124 }
2125
2126 /**
2127 * smack_shm_alloc_security - Set the security blob for shm
2128 * @shp: the object
2129 *
2130 * Returns 0
2131 */
2132 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2133 {
2134 struct kern_ipc_perm *isp = &shp->shm_perm;
2135
2136 isp->security = smk_of_current();
2137 return 0;
2138 }
2139
2140 /**
2141 * smack_shm_free_security - Clear the security blob for shm
2142 * @shp: the object
2143 *
2144 * Clears the blob pointer
2145 */
2146 static void smack_shm_free_security(struct shmid_kernel *shp)
2147 {
2148 struct kern_ipc_perm *isp = &shp->shm_perm;
2149
2150 isp->security = NULL;
2151 }
2152
2153 /**
2154 * smk_curacc_shm : check if current has access on shm
2155 * @shp : the object
2156 * @access : access requested
2157 *
2158 * Returns 0 if current has the requested access, error code otherwise
2159 */
2160 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2161 {
2162 char *ssp = smack_of_shm(shp);
2163 struct smk_audit_info ad;
2164
2165 #ifdef CONFIG_AUDIT
2166 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2167 ad.a.u.ipc_id = shp->shm_perm.id;
2168 #endif
2169 return smk_curacc(ssp, access, &ad);
2170 }
2171
2172 /**
2173 * smack_shm_associate - Smack access check for shm
2174 * @shp: the object
2175 * @shmflg: access requested
2176 *
2177 * Returns 0 if current has the requested access, error code otherwise
2178 */
2179 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2180 {
2181 int may;
2182
2183 may = smack_flags_to_may(shmflg);
2184 return smk_curacc_shm(shp, may);
2185 }
2186
2187 /**
2188 * smack_shm_shmctl - Smack access check for shm
2189 * @shp: the object
2190 * @cmd: what it wants to do
2191 *
2192 * Returns 0 if current has the requested access, error code otherwise
2193 */
2194 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2195 {
2196 int may;
2197
2198 switch (cmd) {
2199 case IPC_STAT:
2200 case SHM_STAT:
2201 may = MAY_READ;
2202 break;
2203 case IPC_SET:
2204 case SHM_LOCK:
2205 case SHM_UNLOCK:
2206 case IPC_RMID:
2207 may = MAY_READWRITE;
2208 break;
2209 case IPC_INFO:
2210 case SHM_INFO:
2211 /*
2212 * System level information.
2213 */
2214 return 0;
2215 default:
2216 return -EINVAL;
2217 }
2218 return smk_curacc_shm(shp, may);
2219 }
2220
2221 /**
2222 * smack_shm_shmat - Smack access for shmat
2223 * @shp: the object
2224 * @shmaddr: unused
2225 * @shmflg: access requested
2226 *
2227 * Returns 0 if current has the requested access, error code otherwise
2228 */
2229 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2230 int shmflg)
2231 {
2232 int may;
2233
2234 may = smack_flags_to_may(shmflg);
2235 return smk_curacc_shm(shp, may);
2236 }
2237
2238 /**
2239 * smack_of_sem - the smack pointer for the sem
2240 * @sma: the object
2241 *
2242 * Returns a pointer to the smack value
2243 */
2244 static char *smack_of_sem(struct sem_array *sma)
2245 {
2246 return (char *)sma->sem_perm.security;
2247 }
2248
2249 /**
2250 * smack_sem_alloc_security - Set the security blob for sem
2251 * @sma: the object
2252 *
2253 * Returns 0
2254 */
2255 static int smack_sem_alloc_security(struct sem_array *sma)
2256 {
2257 struct kern_ipc_perm *isp = &sma->sem_perm;
2258
2259 isp->security = smk_of_current();
2260 return 0;
2261 }
2262
2263 /**
2264 * smack_sem_free_security - Clear the security blob for sem
2265 * @sma: the object
2266 *
2267 * Clears the blob pointer
2268 */
2269 static void smack_sem_free_security(struct sem_array *sma)
2270 {
2271 struct kern_ipc_perm *isp = &sma->sem_perm;
2272
2273 isp->security = NULL;
2274 }
2275
2276 /**
2277 * smk_curacc_sem : check if current has access on sem
2278 * @sma : the object
2279 * @access : access requested
2280 *
2281 * Returns 0 if current has the requested access, error code otherwise
2282 */
2283 static int smk_curacc_sem(struct sem_array *sma, int access)
2284 {
2285 char *ssp = smack_of_sem(sma);
2286 struct smk_audit_info ad;
2287
2288 #ifdef CONFIG_AUDIT
2289 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2290 ad.a.u.ipc_id = sma->sem_perm.id;
2291 #endif
2292 return smk_curacc(ssp, access, &ad);
2293 }
2294
2295 /**
2296 * smack_sem_associate - Smack access check for sem
2297 * @sma: the object
2298 * @semflg: access requested
2299 *
2300 * Returns 0 if current has the requested access, error code otherwise
2301 */
2302 static int smack_sem_associate(struct sem_array *sma, int semflg)
2303 {
2304 int may;
2305
2306 may = smack_flags_to_may(semflg);
2307 return smk_curacc_sem(sma, may);
2308 }
2309
2310 /**
2311 * smack_sem_shmctl - Smack access check for sem
2312 * @sma: the object
2313 * @cmd: what it wants to do
2314 *
2315 * Returns 0 if current has the requested access, error code otherwise
2316 */
2317 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2318 {
2319 int may;
2320
2321 switch (cmd) {
2322 case GETPID:
2323 case GETNCNT:
2324 case GETZCNT:
2325 case GETVAL:
2326 case GETALL:
2327 case IPC_STAT:
2328 case SEM_STAT:
2329 may = MAY_READ;
2330 break;
2331 case SETVAL:
2332 case SETALL:
2333 case IPC_RMID:
2334 case IPC_SET:
2335 may = MAY_READWRITE;
2336 break;
2337 case IPC_INFO:
2338 case SEM_INFO:
2339 /*
2340 * System level information
2341 */
2342 return 0;
2343 default:
2344 return -EINVAL;
2345 }
2346
2347 return smk_curacc_sem(sma, may);
2348 }
2349
2350 /**
2351 * smack_sem_semop - Smack checks of semaphore operations
2352 * @sma: the object
2353 * @sops: unused
2354 * @nsops: unused
2355 * @alter: unused
2356 *
2357 * Treated as read and write in all cases.
2358 *
2359 * Returns 0 if access is allowed, error code otherwise
2360 */
2361 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2362 unsigned nsops, int alter)
2363 {
2364 return smk_curacc_sem(sma, MAY_READWRITE);
2365 }
2366
2367 /**
2368 * smack_msg_alloc_security - Set the security blob for msg
2369 * @msq: the object
2370 *
2371 * Returns 0
2372 */
2373 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2374 {
2375 struct kern_ipc_perm *kisp = &msq->q_perm;
2376
2377 kisp->security = smk_of_current();
2378 return 0;
2379 }
2380
2381 /**
2382 * smack_msg_free_security - Clear the security blob for msg
2383 * @msq: the object
2384 *
2385 * Clears the blob pointer
2386 */
2387 static void smack_msg_queue_free_security(struct msg_queue *msq)
2388 {
2389 struct kern_ipc_perm *kisp = &msq->q_perm;
2390
2391 kisp->security = NULL;
2392 }
2393
2394 /**
2395 * smack_of_msq - the smack pointer for the msq
2396 * @msq: the object
2397 *
2398 * Returns a pointer to the smack value
2399 */
2400 static char *smack_of_msq(struct msg_queue *msq)
2401 {
2402 return (char *)msq->q_perm.security;
2403 }
2404
2405 /**
2406 * smk_curacc_msq : helper to check if current has access on msq
2407 * @msq : the msq
2408 * @access : access requested
2409 *
2410 * return 0 if current has access, error otherwise
2411 */
2412 static int smk_curacc_msq(struct msg_queue *msq, int access)
2413 {
2414 char *msp = smack_of_msq(msq);
2415 struct smk_audit_info ad;
2416
2417 #ifdef CONFIG_AUDIT
2418 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2419 ad.a.u.ipc_id = msq->q_perm.id;
2420 #endif
2421 return smk_curacc(msp, access, &ad);
2422 }
2423
2424 /**
2425 * smack_msg_queue_associate - Smack access check for msg_queue
2426 * @msq: the object
2427 * @msqflg: access requested
2428 *
2429 * Returns 0 if current has the requested access, error code otherwise
2430 */
2431 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2432 {
2433 int may;
2434
2435 may = smack_flags_to_may(msqflg);
2436 return smk_curacc_msq(msq, may);
2437 }
2438
2439 /**
2440 * smack_msg_queue_msgctl - Smack access check for msg_queue
2441 * @msq: the object
2442 * @cmd: what it wants to do
2443 *
2444 * Returns 0 if current has the requested access, error code otherwise
2445 */
2446 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2447 {
2448 int may;
2449
2450 switch (cmd) {
2451 case IPC_STAT:
2452 case MSG_STAT:
2453 may = MAY_READ;
2454 break;
2455 case IPC_SET:
2456 case IPC_RMID:
2457 may = MAY_READWRITE;
2458 break;
2459 case IPC_INFO:
2460 case MSG_INFO:
2461 /*
2462 * System level information
2463 */
2464 return 0;
2465 default:
2466 return -EINVAL;
2467 }
2468
2469 return smk_curacc_msq(msq, may);
2470 }
2471
2472 /**
2473 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2474 * @msq: the object
2475 * @msg: unused
2476 * @msqflg: access requested
2477 *
2478 * Returns 0 if current has the requested access, error code otherwise
2479 */
2480 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2481 int msqflg)
2482 {
2483 int may;
2484
2485 may = smack_flags_to_may(msqflg);
2486 return smk_curacc_msq(msq, may);
2487 }
2488
2489 /**
2490 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2491 * @msq: the object
2492 * @msg: unused
2493 * @target: unused
2494 * @type: unused
2495 * @mode: unused
2496 *
2497 * Returns 0 if current has read and write access, error code otherwise
2498 */
2499 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2500 struct task_struct *target, long type, int mode)
2501 {
2502 return smk_curacc_msq(msq, MAY_READWRITE);
2503 }
2504
2505 /**
2506 * smack_ipc_permission - Smack access for ipc_permission()
2507 * @ipp: the object permissions
2508 * @flag: access requested
2509 *
2510 * Returns 0 if current has read and write access, error code otherwise
2511 */
2512 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2513 {
2514 char *isp = ipp->security;
2515 int may = smack_flags_to_may(flag);
2516 struct smk_audit_info ad;
2517
2518 #ifdef CONFIG_AUDIT
2519 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2520 ad.a.u.ipc_id = ipp->id;
2521 #endif
2522 return smk_curacc(isp, may, &ad);
2523 }
2524
2525 /**
2526 * smack_ipc_getsecid - Extract smack security id
2527 * @ipp: the object permissions
2528 * @secid: where result will be saved
2529 */
2530 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2531 {
2532 char *smack = ipp->security;
2533
2534 *secid = smack_to_secid(smack);
2535 }
2536
2537 /**
2538 * smack_d_instantiate - Make sure the blob is correct on an inode
2539 * @opt_dentry: dentry where inode will be attached
2540 * @inode: the object
2541 *
2542 * Set the inode's security blob if it hasn't been done already.
2543 */
2544 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2545 {
2546 struct super_block *sbp;
2547 struct superblock_smack *sbsp;
2548 struct inode_smack *isp;
2549 char *csp = smk_of_current();
2550 char *fetched;
2551 char *final;
2552 char trattr[TRANS_TRUE_SIZE];
2553 int transflag = 0;
2554 struct dentry *dp;
2555
2556 if (inode == NULL)
2557 return;
2558
2559 isp = inode->i_security;
2560
2561 mutex_lock(&isp->smk_lock);
2562 /*
2563 * If the inode is already instantiated
2564 * take the quick way out
2565 */
2566 if (isp->smk_flags & SMK_INODE_INSTANT)
2567 goto unlockandout;
2568
2569 sbp = inode->i_sb;
2570 sbsp = sbp->s_security;
2571 /*
2572 * We're going to use the superblock default label
2573 * if there's no label on the file.
2574 */
2575 final = sbsp->smk_default;
2576
2577 /*
2578 * If this is the root inode the superblock
2579 * may be in the process of initialization.
2580 * If that is the case use the root value out
2581 * of the superblock.
2582 */
2583 if (opt_dentry->d_parent == opt_dentry) {
2584 isp->smk_inode = sbsp->smk_root;
2585 isp->smk_flags |= SMK_INODE_INSTANT;
2586 goto unlockandout;
2587 }
2588
2589 /*
2590 * This is pretty hackish.
2591 * Casey says that we shouldn't have to do
2592 * file system specific code, but it does help
2593 * with keeping it simple.
2594 */
2595 switch (sbp->s_magic) {
2596 case SMACK_MAGIC:
2597 /*
2598 * Casey says that it's a little embarrassing
2599 * that the smack file system doesn't do
2600 * extended attributes.
2601 */
2602 final = smack_known_star.smk_known;
2603 break;
2604 case PIPEFS_MAGIC:
2605 /*
2606 * Casey says pipes are easy (?)
2607 */
2608 final = smack_known_star.smk_known;
2609 break;
2610 case DEVPTS_SUPER_MAGIC:
2611 /*
2612 * devpts seems content with the label of the task.
2613 * Programs that change smack have to treat the
2614 * pty with respect.
2615 */
2616 final = csp;
2617 break;
2618 case SOCKFS_MAGIC:
2619 /*
2620 * Socket access is controlled by the socket
2621 * structures associated with the task involved.
2622 */
2623 final = smack_known_star.smk_known;
2624 break;
2625 case PROC_SUPER_MAGIC:
2626 /*
2627 * Casey says procfs appears not to care.
2628 * The superblock default suffices.
2629 */
2630 break;
2631 case TMPFS_MAGIC:
2632 /*
2633 * Device labels should come from the filesystem,
2634 * but watch out, because they're volitile,
2635 * getting recreated on every reboot.
2636 */
2637 final = smack_known_star.smk_known;
2638 /*
2639 * No break.
2640 *
2641 * If a smack value has been set we want to use it,
2642 * but since tmpfs isn't giving us the opportunity
2643 * to set mount options simulate setting the
2644 * superblock default.
2645 */
2646 default:
2647 /*
2648 * This isn't an understood special case.
2649 * Get the value from the xattr.
2650 */
2651
2652 /*
2653 * UNIX domain sockets use lower level socket data.
2654 */
2655 if (S_ISSOCK(inode->i_mode)) {
2656 final = smack_known_star.smk_known;
2657 break;
2658 }
2659 /*
2660 * No xattr support means, alas, no SMACK label.
2661 * Use the aforeapplied default.
2662 * It would be curious if the label of the task
2663 * does not match that assigned.
2664 */
2665 if (inode->i_op->getxattr == NULL)
2666 break;
2667 /*
2668 * Get the dentry for xattr.
2669 */
2670 dp = dget(opt_dentry);
2671 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2672 if (fetched != NULL) {
2673 final = fetched;
2674 if (S_ISDIR(inode->i_mode)) {
2675 trattr[0] = '\0';
2676 inode->i_op->getxattr(dp,
2677 XATTR_NAME_SMACKTRANSMUTE,
2678 trattr, TRANS_TRUE_SIZE);
2679 if (strncmp(trattr, TRANS_TRUE,
2680 TRANS_TRUE_SIZE) == 0)
2681 transflag = SMK_INODE_TRANSMUTE;
2682 }
2683 }
2684 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2685 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2686
2687 dput(dp);
2688 break;
2689 }
2690
2691 if (final == NULL)
2692 isp->smk_inode = csp;
2693 else
2694 isp->smk_inode = final;
2695
2696 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2697
2698 unlockandout:
2699 mutex_unlock(&isp->smk_lock);
2700 return;
2701 }
2702
2703 /**
2704 * smack_getprocattr - Smack process attribute access
2705 * @p: the object task
2706 * @name: the name of the attribute in /proc/.../attr
2707 * @value: where to put the result
2708 *
2709 * Places a copy of the task Smack into value
2710 *
2711 * Returns the length of the smack label or an error code
2712 */
2713 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2714 {
2715 char *cp;
2716 int slen;
2717
2718 if (strcmp(name, "current") != 0)
2719 return -EINVAL;
2720
2721 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2722 if (cp == NULL)
2723 return -ENOMEM;
2724
2725 slen = strlen(cp);
2726 *value = cp;
2727 return slen;
2728 }
2729
2730 /**
2731 * smack_setprocattr - Smack process attribute setting
2732 * @p: the object task
2733 * @name: the name of the attribute in /proc/.../attr
2734 * @value: the value to set
2735 * @size: the size of the value
2736 *
2737 * Sets the Smack value of the task. Only setting self
2738 * is permitted and only with privilege
2739 *
2740 * Returns the length of the smack label or an error code
2741 */
2742 static int smack_setprocattr(struct task_struct *p, char *name,
2743 void *value, size_t size)
2744 {
2745 int rc;
2746 struct task_smack *tsp;
2747 struct task_smack *oldtsp;
2748 struct cred *new;
2749 char *newsmack;
2750
2751 /*
2752 * Changing another process' Smack value is too dangerous
2753 * and supports no sane use case.
2754 */
2755 if (p != current)
2756 return -EPERM;
2757
2758 if (!capable(CAP_MAC_ADMIN))
2759 return -EPERM;
2760
2761 if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2762 return -EINVAL;
2763
2764 if (strcmp(name, "current") != 0)
2765 return -EINVAL;
2766
2767 newsmack = smk_import(value, size);
2768 if (newsmack == NULL)
2769 return -EINVAL;
2770
2771 /*
2772 * No process is ever allowed the web ("@") label.
2773 */
2774 if (newsmack == smack_known_web.smk_known)
2775 return -EPERM;
2776
2777 oldtsp = p->cred->security;
2778 new = prepare_creds();
2779 if (new == NULL)
2780 return -ENOMEM;
2781
2782 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2783 if (tsp == NULL) {
2784 kfree(new);
2785 return -ENOMEM;
2786 }
2787 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2788 if (rc != 0)
2789 return rc;
2790
2791 new->security = tsp;
2792 commit_creds(new);
2793 return size;
2794 }
2795
2796 /**
2797 * smack_unix_stream_connect - Smack access on UDS
2798 * @sock: one sock
2799 * @other: the other sock
2800 * @newsk: unused
2801 *
2802 * Return 0 if a subject with the smack of sock could access
2803 * an object with the smack of other, otherwise an error code
2804 */
2805 static int smack_unix_stream_connect(struct sock *sock,
2806 struct sock *other, struct sock *newsk)
2807 {
2808 struct socket_smack *ssp = sock->sk_security;
2809 struct socket_smack *osp = other->sk_security;
2810 struct socket_smack *nsp = newsk->sk_security;
2811 struct smk_audit_info ad;
2812 struct lsm_network_audit net;
2813 int rc = 0;
2814
2815 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2816 smk_ad_setfield_u_net_sk(&ad, other);
2817
2818 if (!capable(CAP_MAC_OVERRIDE))
2819 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2820
2821 /*
2822 * Cross reference the peer labels for SO_PEERSEC.
2823 */
2824 if (rc == 0) {
2825 nsp->smk_packet = ssp->smk_out;
2826 ssp->smk_packet = osp->smk_out;
2827 }
2828
2829 return rc;
2830 }
2831
2832 /**
2833 * smack_unix_may_send - Smack access on UDS
2834 * @sock: one socket
2835 * @other: the other socket
2836 *
2837 * Return 0 if a subject with the smack of sock could access
2838 * an object with the smack of other, otherwise an error code
2839 */
2840 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2841 {
2842 struct socket_smack *ssp = sock->sk->sk_security;
2843 struct socket_smack *osp = other->sk->sk_security;
2844 struct smk_audit_info ad;
2845 struct lsm_network_audit net;
2846 int rc = 0;
2847
2848 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2849 smk_ad_setfield_u_net_sk(&ad, other->sk);
2850
2851 if (!capable(CAP_MAC_OVERRIDE))
2852 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2853
2854 return rc;
2855 }
2856
2857 /**
2858 * smack_socket_sendmsg - Smack check based on destination host
2859 * @sock: the socket
2860 * @msg: the message
2861 * @size: the size of the message
2862 *
2863 * Return 0 if the current subject can write to the destination
2864 * host. This is only a question if the destination is a single
2865 * label host.
2866 */
2867 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2868 int size)
2869 {
2870 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2871
2872 /*
2873 * Perfectly reasonable for this to be NULL
2874 */
2875 if (sip == NULL || sip->sin_family != AF_INET)
2876 return 0;
2877
2878 return smack_netlabel_send(sock->sk, sip);
2879 }
2880
2881 /**
2882 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2883 * @sap: netlabel secattr
2884 * @ssp: socket security information
2885 *
2886 * Returns a pointer to a Smack label found on the label list.
2887 */
2888 static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
2889 struct socket_smack *ssp)
2890 {
2891 struct smack_known *skp;
2892 char smack[SMK_LABELLEN];
2893 char *sp;
2894 int pcat;
2895
2896 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2897 /*
2898 * Looks like a CIPSO packet.
2899 * If there are flags but no level netlabel isn't
2900 * behaving the way we expect it to.
2901 *
2902 * Get the categories, if any
2903 * Without guidance regarding the smack value
2904 * for the packet fall back on the network
2905 * ambient value.
2906 */
2907 memset(smack, '\0', SMK_LABELLEN);
2908 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2909 for (pcat = -1;;) {
2910 pcat = netlbl_secattr_catmap_walk(
2911 sap->attr.mls.cat, pcat + 1);
2912 if (pcat < 0)
2913 break;
2914 smack_catset_bit(pcat, smack);
2915 }
2916 /*
2917 * If it is CIPSO using smack direct mapping
2918 * we are already done. WeeHee.
2919 */
2920 if (sap->attr.mls.lvl == smack_cipso_direct) {
2921 /*
2922 * The label sent is usually on the label list.
2923 *
2924 * If it is not we may still want to allow the
2925 * delivery.
2926 *
2927 * If the recipient is accepting all packets
2928 * because it is using the star ("*") label
2929 * for SMACK64IPIN provide the web ("@") label
2930 * so that a directed response will succeed.
2931 * This is not very correct from a MAC point
2932 * of view, but gets around the problem that
2933 * locking prevents adding the newly discovered
2934 * label to the list.
2935 * The case where the recipient is not using
2936 * the star label should obviously fail.
2937 * The easy way to do this is to provide the
2938 * star label as the subject label.
2939 */
2940 skp = smk_find_entry(smack);
2941 if (skp != NULL)
2942 return skp->smk_known;
2943 if (ssp != NULL &&
2944 ssp->smk_in == smack_known_star.smk_known)
2945 return smack_known_web.smk_known;
2946 return smack_known_star.smk_known;
2947 }
2948 /*
2949 * Look it up in the supplied table if it is not
2950 * a direct mapping.
2951 */
2952 sp = smack_from_cipso(sap->attr.mls.lvl, smack);
2953 if (sp != NULL)
2954 return sp;
2955 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
2956 return smack_known_web.smk_known;
2957 return smack_known_star.smk_known;
2958 }
2959 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2960 /*
2961 * Looks like a fallback, which gives us a secid.
2962 */
2963 sp = smack_from_secid(sap->attr.secid);
2964 /*
2965 * This has got to be a bug because it is
2966 * impossible to specify a fallback without
2967 * specifying the label, which will ensure
2968 * it has a secid, and the only way to get a
2969 * secid is from a fallback.
2970 */
2971 BUG_ON(sp == NULL);
2972 return sp;
2973 }
2974 /*
2975 * Without guidance regarding the smack value
2976 * for the packet fall back on the network
2977 * ambient value.
2978 */
2979 return smack_net_ambient;
2980 }
2981
2982 /**
2983 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2984 * @sk: socket
2985 * @skb: packet
2986 *
2987 * Returns 0 if the packet should be delivered, an error code otherwise
2988 */
2989 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2990 {
2991 struct netlbl_lsm_secattr secattr;
2992 struct socket_smack *ssp = sk->sk_security;
2993 char *csp;
2994 int rc;
2995 struct smk_audit_info ad;
2996 struct lsm_network_audit net;
2997 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2998 return 0;
2999
3000 /*
3001 * Translate what netlabel gave us.
3002 */
3003 netlbl_secattr_init(&secattr);
3004
3005 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
3006 if (rc == 0)
3007 csp = smack_from_secattr(&secattr, ssp);
3008 else
3009 csp = smack_net_ambient;
3010
3011 netlbl_secattr_destroy(&secattr);
3012
3013 #ifdef CONFIG_AUDIT
3014 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3015 ad.a.u.net->family = sk->sk_family;
3016 ad.a.u.net->netif = skb->skb_iif;
3017 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3018 #endif
3019 /*
3020 * Receiving a packet requires that the other end
3021 * be able to write here. Read access is not required.
3022 * This is the simplist possible security model
3023 * for networking.
3024 */
3025 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
3026 if (rc != 0)
3027 netlbl_skbuff_err(skb, rc, 0);
3028 return rc;
3029 }
3030
3031 /**
3032 * smack_socket_getpeersec_stream - pull in packet label
3033 * @sock: the socket
3034 * @optval: user's destination
3035 * @optlen: size thereof
3036 * @len: max thereof
3037 *
3038 * returns zero on success, an error code otherwise
3039 */
3040 static int smack_socket_getpeersec_stream(struct socket *sock,
3041 char __user *optval,
3042 int __user *optlen, unsigned len)
3043 {
3044 struct socket_smack *ssp;
3045 char *rcp = "";
3046 int slen = 1;
3047 int rc = 0;
3048
3049 ssp = sock->sk->sk_security;
3050 if (ssp->smk_packet != NULL) {
3051 rcp = ssp->smk_packet;
3052 slen = strlen(rcp) + 1;
3053 }
3054
3055 if (slen > len)
3056 rc = -ERANGE;
3057 else if (copy_to_user(optval, rcp, slen) != 0)
3058 rc = -EFAULT;
3059
3060 if (put_user(slen, optlen) != 0)
3061 rc = -EFAULT;
3062
3063 return rc;
3064 }
3065
3066
3067 /**
3068 * smack_socket_getpeersec_dgram - pull in packet label
3069 * @sock: the peer socket
3070 * @skb: packet data
3071 * @secid: pointer to where to put the secid of the packet
3072 *
3073 * Sets the netlabel socket state on sk from parent
3074 */
3075 static int smack_socket_getpeersec_dgram(struct socket *sock,
3076 struct sk_buff *skb, u32 *secid)
3077
3078 {
3079 struct netlbl_lsm_secattr secattr;
3080 struct socket_smack *ssp = NULL;
3081 char *sp;
3082 int family = PF_UNSPEC;
3083 u32 s = 0; /* 0 is the invalid secid */
3084 int rc;
3085
3086 if (skb != NULL) {
3087 if (skb->protocol == htons(ETH_P_IP))
3088 family = PF_INET;
3089 else if (skb->protocol == htons(ETH_P_IPV6))
3090 family = PF_INET6;
3091 }
3092 if (family == PF_UNSPEC && sock != NULL)
3093 family = sock->sk->sk_family;
3094
3095 if (family == PF_UNIX) {
3096 ssp = sock->sk->sk_security;
3097 s = smack_to_secid(ssp->smk_out);
3098 } else if (family == PF_INET || family == PF_INET6) {
3099 /*
3100 * Translate what netlabel gave us.
3101 */
3102 if (sock != NULL && sock->sk != NULL)
3103 ssp = sock->sk->sk_security;
3104 netlbl_secattr_init(&secattr);
3105 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3106 if (rc == 0) {
3107 sp = smack_from_secattr(&secattr, ssp);
3108 s = smack_to_secid(sp);
3109 }
3110 netlbl_secattr_destroy(&secattr);
3111 }
3112 *secid = s;
3113 if (s == 0)
3114 return -EINVAL;
3115 return 0;
3116 }
3117
3118 /**
3119 * smack_sock_graft - Initialize a newly created socket with an existing sock
3120 * @sk: child sock
3121 * @parent: parent socket
3122 *
3123 * Set the smk_{in,out} state of an existing sock based on the process that
3124 * is creating the new socket.
3125 */
3126 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3127 {
3128 struct socket_smack *ssp;
3129
3130 if (sk == NULL ||
3131 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3132 return;
3133
3134 ssp = sk->sk_security;
3135 ssp->smk_in = ssp->smk_out = smk_of_current();
3136 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3137 }
3138
3139 /**
3140 * smack_inet_conn_request - Smack access check on connect
3141 * @sk: socket involved
3142 * @skb: packet
3143 * @req: unused
3144 *
3145 * Returns 0 if a task with the packet label could write to
3146 * the socket, otherwise an error code
3147 */
3148 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3149 struct request_sock *req)
3150 {
3151 u16 family = sk->sk_family;
3152 struct socket_smack *ssp = sk->sk_security;
3153 struct netlbl_lsm_secattr secattr;
3154 struct sockaddr_in addr;
3155 struct iphdr *hdr;
3156 char *sp;
3157 int rc;
3158 struct smk_audit_info ad;
3159 struct lsm_network_audit net;
3160
3161 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3162 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3163 family = PF_INET;
3164
3165 netlbl_secattr_init(&secattr);
3166 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3167 if (rc == 0)
3168 sp = smack_from_secattr(&secattr, ssp);
3169 else
3170 sp = smack_known_huh.smk_known;
3171 netlbl_secattr_destroy(&secattr);
3172
3173 #ifdef CONFIG_AUDIT
3174 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3175 ad.a.u.net->family = family;
3176 ad.a.u.net->netif = skb->skb_iif;
3177 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3178 #endif
3179 /*
3180 * Receiving a packet requires that the other end be able to write
3181 * here. Read access is not required.
3182 */
3183 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
3184 if (rc != 0)
3185 return rc;
3186
3187 /*
3188 * Save the peer's label in the request_sock so we can later setup
3189 * smk_packet in the child socket so that SO_PEERCRED can report it.
3190 */
3191 req->peer_secid = smack_to_secid(sp);
3192
3193 /*
3194 * We need to decide if we want to label the incoming connection here
3195 * if we do we only need to label the request_sock and the stack will
3196 * propagate the wire-label to the sock when it is created.
3197 */
3198 hdr = ip_hdr(skb);
3199 addr.sin_addr.s_addr = hdr->saddr;
3200 rcu_read_lock();
3201 if (smack_host_label(&addr) == NULL) {
3202 rcu_read_unlock();
3203 netlbl_secattr_init(&secattr);
3204 smack_to_secattr(sp, &secattr);
3205 rc = netlbl_req_setattr(req, &secattr);
3206 netlbl_secattr_destroy(&secattr);
3207 } else {
3208 rcu_read_unlock();
3209 netlbl_req_delattr(req);
3210 }
3211
3212 return rc;
3213 }
3214
3215 /**
3216 * smack_inet_csk_clone - Copy the connection information to the new socket
3217 * @sk: the new socket
3218 * @req: the connection's request_sock
3219 *
3220 * Transfer the connection's peer label to the newly created socket.
3221 */
3222 static void smack_inet_csk_clone(struct sock *sk,
3223 const struct request_sock *req)
3224 {
3225 struct socket_smack *ssp = sk->sk_security;
3226
3227 if (req->peer_secid != 0)
3228 ssp->smk_packet = smack_from_secid(req->peer_secid);
3229 else
3230 ssp->smk_packet = NULL;
3231 }
3232
3233 /*
3234 * Key management security hooks
3235 *
3236 * Casey has not tested key support very heavily.
3237 * The permission check is most likely too restrictive.
3238 * If you care about keys please have a look.
3239 */
3240 #ifdef CONFIG_KEYS
3241
3242 /**
3243 * smack_key_alloc - Set the key security blob
3244 * @key: object
3245 * @cred: the credentials to use
3246 * @flags: unused
3247 *
3248 * No allocation required
3249 *
3250 * Returns 0
3251 */
3252 static int smack_key_alloc(struct key *key, const struct cred *cred,
3253 unsigned long flags)
3254 {
3255 key->security = smk_of_task(cred->security);
3256 return 0;
3257 }
3258
3259 /**
3260 * smack_key_free - Clear the key security blob
3261 * @key: the object
3262 *
3263 * Clear the blob pointer
3264 */
3265 static void smack_key_free(struct key *key)
3266 {
3267 key->security = NULL;
3268 }
3269
3270 /*
3271 * smack_key_permission - Smack access on a key
3272 * @key_ref: gets to the object
3273 * @cred: the credentials to use
3274 * @perm: unused
3275 *
3276 * Return 0 if the task has read and write to the object,
3277 * an error code otherwise
3278 */
3279 static int smack_key_permission(key_ref_t key_ref,
3280 const struct cred *cred, key_perm_t perm)
3281 {
3282 struct key *keyp;
3283 struct smk_audit_info ad;
3284 char *tsp = smk_of_task(cred->security);
3285
3286 keyp = key_ref_to_ptr(key_ref);
3287 if (keyp == NULL)
3288 return -EINVAL;
3289 /*
3290 * If the key hasn't been initialized give it access so that
3291 * it may do so.
3292 */
3293 if (keyp->security == NULL)
3294 return 0;
3295 /*
3296 * This should not occur
3297 */
3298 if (tsp == NULL)
3299 return -EACCES;
3300 #ifdef CONFIG_AUDIT
3301 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3302 ad.a.u.key_struct.key = keyp->serial;
3303 ad.a.u.key_struct.key_desc = keyp->description;
3304 #endif
3305 return smk_access(tsp, keyp->security,
3306 MAY_READWRITE, &ad);
3307 }
3308 #endif /* CONFIG_KEYS */
3309
3310 /*
3311 * Smack Audit hooks
3312 *
3313 * Audit requires a unique representation of each Smack specific
3314 * rule. This unique representation is used to distinguish the
3315 * object to be audited from remaining kernel objects and also
3316 * works as a glue between the audit hooks.
3317 *
3318 * Since repository entries are added but never deleted, we'll use
3319 * the smack_known label address related to the given audit rule as
3320 * the needed unique representation. This also better fits the smack
3321 * model where nearly everything is a label.
3322 */
3323 #ifdef CONFIG_AUDIT
3324
3325 /**
3326 * smack_audit_rule_init - Initialize a smack audit rule
3327 * @field: audit rule fields given from user-space (audit.h)
3328 * @op: required testing operator (=, !=, >, <, ...)
3329 * @rulestr: smack label to be audited
3330 * @vrule: pointer to save our own audit rule representation
3331 *
3332 * Prepare to audit cases where (@field @op @rulestr) is true.
3333 * The label to be audited is created if necessay.
3334 */
3335 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3336 {
3337 char **rule = (char **)vrule;
3338 *rule = NULL;
3339
3340 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3341 return -EINVAL;
3342
3343 if (op != Audit_equal && op != Audit_not_equal)
3344 return -EINVAL;
3345
3346 *rule = smk_import(rulestr, 0);
3347
3348 return 0;
3349 }
3350
3351 /**
3352 * smack_audit_rule_known - Distinguish Smack audit rules
3353 * @krule: rule of interest, in Audit kernel representation format
3354 *
3355 * This is used to filter Smack rules from remaining Audit ones.
3356 * If it's proved that this rule belongs to us, the
3357 * audit_rule_match hook will be called to do the final judgement.
3358 */
3359 static int smack_audit_rule_known(struct audit_krule *krule)
3360 {
3361 struct audit_field *f;
3362 int i;
3363
3364 for (i = 0; i < krule->field_count; i++) {
3365 f = &krule->fields[i];
3366
3367 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3368 return 1;
3369 }
3370
3371 return 0;
3372 }
3373
3374 /**
3375 * smack_audit_rule_match - Audit given object ?
3376 * @secid: security id for identifying the object to test
3377 * @field: audit rule flags given from user-space
3378 * @op: required testing operator
3379 * @vrule: smack internal rule presentation
3380 * @actx: audit context associated with the check
3381 *
3382 * The core Audit hook. It's used to take the decision of
3383 * whether to audit or not to audit a given object.
3384 */
3385 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3386 struct audit_context *actx)
3387 {
3388 char *smack;
3389 char *rule = vrule;
3390
3391 if (!rule) {
3392 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3393 "Smack: missing rule\n");
3394 return -ENOENT;
3395 }
3396
3397 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3398 return 0;
3399
3400 smack = smack_from_secid(secid);
3401
3402 /*
3403 * No need to do string comparisons. If a match occurs,
3404 * both pointers will point to the same smack_known
3405 * label.
3406 */
3407 if (op == Audit_equal)
3408 return (rule == smack);
3409 if (op == Audit_not_equal)
3410 return (rule != smack);
3411
3412 return 0;
3413 }
3414
3415 /**
3416 * smack_audit_rule_free - free smack rule representation
3417 * @vrule: rule to be freed.
3418 *
3419 * No memory was allocated.
3420 */
3421 static void smack_audit_rule_free(void *vrule)
3422 {
3423 /* No-op */
3424 }
3425
3426 #endif /* CONFIG_AUDIT */
3427
3428 /**
3429 * smack_secid_to_secctx - return the smack label for a secid
3430 * @secid: incoming integer
3431 * @secdata: destination
3432 * @seclen: how long it is
3433 *
3434 * Exists for networking code.
3435 */
3436 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3437 {
3438 char *sp = smack_from_secid(secid);
3439
3440 if (secdata)
3441 *secdata = sp;
3442 *seclen = strlen(sp);
3443 return 0;
3444 }
3445
3446 /**
3447 * smack_secctx_to_secid - return the secid for a smack label
3448 * @secdata: smack label
3449 * @seclen: how long result is
3450 * @secid: outgoing integer
3451 *
3452 * Exists for audit and networking code.
3453 */
3454 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3455 {
3456 *secid = smack_to_secid(secdata);
3457 return 0;
3458 }
3459
3460 /**
3461 * smack_release_secctx - don't do anything.
3462 * @secdata: unused
3463 * @seclen: unused
3464 *
3465 * Exists to make sure nothing gets done, and properly
3466 */
3467 static void smack_release_secctx(char *secdata, u32 seclen)
3468 {
3469 }
3470
3471 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3472 {
3473 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3474 }
3475
3476 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3477 {
3478 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3479 }
3480
3481 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3482 {
3483 int len = 0;
3484 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3485
3486 if (len < 0)
3487 return len;
3488 *ctxlen = len;
3489 return 0;
3490 }
3491
3492 struct security_operations smack_ops = {
3493 .name = "smack",
3494
3495 .ptrace_access_check = smack_ptrace_access_check,
3496 .ptrace_traceme = smack_ptrace_traceme,
3497 .syslog = smack_syslog,
3498
3499 .sb_alloc_security = smack_sb_alloc_security,
3500 .sb_free_security = smack_sb_free_security,
3501 .sb_copy_data = smack_sb_copy_data,
3502 .sb_kern_mount = smack_sb_kern_mount,
3503 .sb_statfs = smack_sb_statfs,
3504 .sb_mount = smack_sb_mount,
3505 .sb_umount = smack_sb_umount,
3506
3507 .bprm_set_creds = smack_bprm_set_creds,
3508 .bprm_committing_creds = smack_bprm_committing_creds,
3509 .bprm_secureexec = smack_bprm_secureexec,
3510
3511 .inode_alloc_security = smack_inode_alloc_security,
3512 .inode_free_security = smack_inode_free_security,
3513 .inode_init_security = smack_inode_init_security,
3514 .inode_link = smack_inode_link,
3515 .inode_unlink = smack_inode_unlink,
3516 .inode_rmdir = smack_inode_rmdir,
3517 .inode_rename = smack_inode_rename,
3518 .inode_permission = smack_inode_permission,
3519 .inode_setattr = smack_inode_setattr,
3520 .inode_getattr = smack_inode_getattr,
3521 .inode_setxattr = smack_inode_setxattr,
3522 .inode_post_setxattr = smack_inode_post_setxattr,
3523 .inode_getxattr = smack_inode_getxattr,
3524 .inode_removexattr = smack_inode_removexattr,
3525 .inode_getsecurity = smack_inode_getsecurity,
3526 .inode_setsecurity = smack_inode_setsecurity,
3527 .inode_listsecurity = smack_inode_listsecurity,
3528 .inode_getsecid = smack_inode_getsecid,
3529
3530 .file_permission = smack_file_permission,
3531 .file_alloc_security = smack_file_alloc_security,
3532 .file_free_security = smack_file_free_security,
3533 .file_ioctl = smack_file_ioctl,
3534 .file_lock = smack_file_lock,
3535 .file_fcntl = smack_file_fcntl,
3536 .file_mmap = smack_file_mmap,
3537 .file_set_fowner = smack_file_set_fowner,
3538 .file_send_sigiotask = smack_file_send_sigiotask,
3539 .file_receive = smack_file_receive,
3540
3541 .dentry_open = smack_dentry_open,
3542
3543 .cred_alloc_blank = smack_cred_alloc_blank,
3544 .cred_free = smack_cred_free,
3545 .cred_prepare = smack_cred_prepare,
3546 .cred_transfer = smack_cred_transfer,
3547 .kernel_act_as = smack_kernel_act_as,
3548 .kernel_create_files_as = smack_kernel_create_files_as,
3549 .task_setpgid = smack_task_setpgid,
3550 .task_getpgid = smack_task_getpgid,
3551 .task_getsid = smack_task_getsid,
3552 .task_getsecid = smack_task_getsecid,
3553 .task_setnice = smack_task_setnice,
3554 .task_setioprio = smack_task_setioprio,
3555 .task_getioprio = smack_task_getioprio,
3556 .task_setscheduler = smack_task_setscheduler,
3557 .task_getscheduler = smack_task_getscheduler,
3558 .task_movememory = smack_task_movememory,
3559 .task_kill = smack_task_kill,
3560 .task_wait = smack_task_wait,
3561 .task_to_inode = smack_task_to_inode,
3562
3563 .ipc_permission = smack_ipc_permission,
3564 .ipc_getsecid = smack_ipc_getsecid,
3565
3566 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3567 .msg_msg_free_security = smack_msg_msg_free_security,
3568
3569 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3570 .msg_queue_free_security = smack_msg_queue_free_security,
3571 .msg_queue_associate = smack_msg_queue_associate,
3572 .msg_queue_msgctl = smack_msg_queue_msgctl,
3573 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3574 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3575
3576 .shm_alloc_security = smack_shm_alloc_security,
3577 .shm_free_security = smack_shm_free_security,
3578 .shm_associate = smack_shm_associate,
3579 .shm_shmctl = smack_shm_shmctl,
3580 .shm_shmat = smack_shm_shmat,
3581
3582 .sem_alloc_security = smack_sem_alloc_security,
3583 .sem_free_security = smack_sem_free_security,
3584 .sem_associate = smack_sem_associate,
3585 .sem_semctl = smack_sem_semctl,
3586 .sem_semop = smack_sem_semop,
3587
3588 .d_instantiate = smack_d_instantiate,
3589
3590 .getprocattr = smack_getprocattr,
3591 .setprocattr = smack_setprocattr,
3592
3593 .unix_stream_connect = smack_unix_stream_connect,
3594 .unix_may_send = smack_unix_may_send,
3595
3596 .socket_post_create = smack_socket_post_create,
3597 .socket_connect = smack_socket_connect,
3598 .socket_sendmsg = smack_socket_sendmsg,
3599 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3600 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3601 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3602 .sk_alloc_security = smack_sk_alloc_security,
3603 .sk_free_security = smack_sk_free_security,
3604 .sock_graft = smack_sock_graft,
3605 .inet_conn_request = smack_inet_conn_request,
3606 .inet_csk_clone = smack_inet_csk_clone,
3607
3608 /* key management security hooks */
3609 #ifdef CONFIG_KEYS
3610 .key_alloc = smack_key_alloc,
3611 .key_free = smack_key_free,
3612 .key_permission = smack_key_permission,
3613 #endif /* CONFIG_KEYS */
3614
3615 /* Audit hooks */
3616 #ifdef CONFIG_AUDIT
3617 .audit_rule_init = smack_audit_rule_init,
3618 .audit_rule_known = smack_audit_rule_known,
3619 .audit_rule_match = smack_audit_rule_match,
3620 .audit_rule_free = smack_audit_rule_free,
3621 #endif /* CONFIG_AUDIT */
3622
3623 .secid_to_secctx = smack_secid_to_secctx,
3624 .secctx_to_secid = smack_secctx_to_secid,
3625 .release_secctx = smack_release_secctx,
3626 .inode_notifysecctx = smack_inode_notifysecctx,
3627 .inode_setsecctx = smack_inode_setsecctx,
3628 .inode_getsecctx = smack_inode_getsecctx,
3629 };
3630
3631
3632 static __init void init_smack_know_list(void)
3633 {
3634 list_add(&smack_known_huh.list, &smack_known_list);
3635 list_add(&smack_known_hat.list, &smack_known_list);
3636 list_add(&smack_known_star.list, &smack_known_list);
3637 list_add(&smack_known_floor.list, &smack_known_list);
3638 list_add(&smack_known_invalid.list, &smack_known_list);
3639 list_add(&smack_known_web.list, &smack_known_list);
3640 }
3641
3642 /**
3643 * smack_init - initialize the smack system
3644 *
3645 * Returns 0
3646 */
3647 static __init int smack_init(void)
3648 {
3649 struct cred *cred;
3650 struct task_smack *tsp;
3651
3652 if (!security_module_enable(&smack_ops))
3653 return 0;
3654
3655 tsp = new_task_smack(smack_known_floor.smk_known,
3656 smack_known_floor.smk_known, GFP_KERNEL);
3657 if (tsp == NULL)
3658 return -ENOMEM;
3659
3660 printk(KERN_INFO "Smack: Initializing.\n");
3661
3662 /*
3663 * Set the security state for the initial task.
3664 */
3665 cred = (struct cred *) current->cred;
3666 cred->security = tsp;
3667
3668 /* initialize the smack_know_list */
3669 init_smack_know_list();
3670 /*
3671 * Initialize locks
3672 */
3673 spin_lock_init(&smack_known_huh.smk_cipsolock);
3674 spin_lock_init(&smack_known_hat.smk_cipsolock);
3675 spin_lock_init(&smack_known_star.smk_cipsolock);
3676 spin_lock_init(&smack_known_floor.smk_cipsolock);
3677 spin_lock_init(&smack_known_invalid.smk_cipsolock);
3678
3679 /*
3680 * Register with LSM
3681 */
3682 if (register_security(&smack_ops))
3683 panic("smack: Unable to register with kernel.\n");
3684
3685 return 0;
3686 }
3687
3688 /*
3689 * Smack requires early initialization in order to label
3690 * all processes and objects when they are created.
3691 */
3692 security_initcall(smack_init);