Smack: onlycap limits on CAP_MAC_ADMIN
[deliverable/linux.git] / security / smack / smack_lsm.c
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/cipso_ipv4.h>
34 #include <linux/audit.h>
35 #include <linux/magic.h>
36 #include <linux/dcache.h>
37 #include <linux/personality.h>
38 #include <linux/msg.h>
39 #include <linux/shm.h>
40 #include <linux/binfmts.h>
41 #include "smack.h"
42
43 #define task_security(task) (task_cred_xxx((task), security))
44
45 #define TRANS_TRUE "TRUE"
46 #define TRANS_TRUE_SIZE 4
47
48 /**
49 * smk_fetch - Fetch the smack label from a file.
50 * @ip: a pointer to the inode
51 * @dp: a pointer to the dentry
52 *
53 * Returns a pointer to the master list entry for the Smack label
54 * or NULL if there was no label to fetch.
55 */
56 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
57 {
58 int rc;
59 char *buffer;
60 char *result = NULL;
61
62 if (ip->i_op->getxattr == NULL)
63 return NULL;
64
65 buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
66 if (buffer == NULL)
67 return NULL;
68
69 rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
70 if (rc > 0)
71 result = smk_import(buffer, rc);
72
73 kfree(buffer);
74
75 return result;
76 }
77
78 /**
79 * new_inode_smack - allocate an inode security blob
80 * @smack: a pointer to the Smack label to use in the blob
81 *
82 * Returns the new blob or NULL if there's no memory available
83 */
84 struct inode_smack *new_inode_smack(char *smack)
85 {
86 struct inode_smack *isp;
87
88 isp = kzalloc(sizeof(struct inode_smack), GFP_NOFS);
89 if (isp == NULL)
90 return NULL;
91
92 isp->smk_inode = smack;
93 isp->smk_flags = 0;
94 mutex_init(&isp->smk_lock);
95
96 return isp;
97 }
98
99 /**
100 * new_task_smack - allocate a task security blob
101 * @smack: a pointer to the Smack label to use in the blob
102 *
103 * Returns the new blob or NULL if there's no memory available
104 */
105 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
106 {
107 struct task_smack *tsp;
108
109 tsp = kzalloc(sizeof(struct task_smack), gfp);
110 if (tsp == NULL)
111 return NULL;
112
113 tsp->smk_task = task;
114 tsp->smk_forked = forked;
115 INIT_LIST_HEAD(&tsp->smk_rules);
116 mutex_init(&tsp->smk_rules_lock);
117
118 return tsp;
119 }
120
121 /**
122 * smk_copy_rules - copy a rule set
123 * @nhead - new rules header pointer
124 * @ohead - old rules header pointer
125 *
126 * Returns 0 on success, -ENOMEM on error
127 */
128 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
129 gfp_t gfp)
130 {
131 struct smack_rule *nrp;
132 struct smack_rule *orp;
133 int rc = 0;
134
135 INIT_LIST_HEAD(nhead);
136
137 list_for_each_entry_rcu(orp, ohead, list) {
138 nrp = kzalloc(sizeof(struct smack_rule), gfp);
139 if (nrp == NULL) {
140 rc = -ENOMEM;
141 break;
142 }
143 *nrp = *orp;
144 list_add_rcu(&nrp->list, nhead);
145 }
146 return rc;
147 }
148
149 /*
150 * LSM hooks.
151 * We he, that is fun!
152 */
153
154 /**
155 * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
156 * @ctp: child task pointer
157 * @mode: ptrace attachment mode
158 *
159 * Returns 0 if access is OK, an error code otherwise
160 *
161 * Do the capability checks, and require read and write.
162 */
163 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
164 {
165 int rc;
166 struct smk_audit_info ad;
167 char *tsp;
168
169 rc = cap_ptrace_access_check(ctp, mode);
170 if (rc != 0)
171 return rc;
172
173 tsp = smk_of_task(task_security(ctp));
174 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
175 smk_ad_setfield_u_tsk(&ad, ctp);
176
177 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
178 return rc;
179 }
180
181 /**
182 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
183 * @ptp: parent task pointer
184 *
185 * Returns 0 if access is OK, an error code otherwise
186 *
187 * Do the capability checks, and require read and write.
188 */
189 static int smack_ptrace_traceme(struct task_struct *ptp)
190 {
191 int rc;
192 struct smk_audit_info ad;
193 char *tsp;
194
195 rc = cap_ptrace_traceme(ptp);
196 if (rc != 0)
197 return rc;
198
199 tsp = smk_of_task(task_security(ptp));
200 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
201 smk_ad_setfield_u_tsk(&ad, ptp);
202
203 rc = smk_curacc(tsp, MAY_READWRITE, &ad);
204 return rc;
205 }
206
207 /**
208 * smack_syslog - Smack approval on syslog
209 * @type: message type
210 *
211 * Require that the task has the floor label
212 *
213 * Returns 0 on success, error code otherwise.
214 */
215 static int smack_syslog(int typefrom_file)
216 {
217 int rc = 0;
218 char *sp = smk_of_current();
219
220 if (smack_privileged(CAP_MAC_OVERRIDE))
221 return 0;
222
223 if (sp != smack_known_floor.smk_known)
224 rc = -EACCES;
225
226 return rc;
227 }
228
229
230 /*
231 * Superblock Hooks.
232 */
233
234 /**
235 * smack_sb_alloc_security - allocate a superblock blob
236 * @sb: the superblock getting the blob
237 *
238 * Returns 0 on success or -ENOMEM on error.
239 */
240 static int smack_sb_alloc_security(struct super_block *sb)
241 {
242 struct superblock_smack *sbsp;
243
244 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
245
246 if (sbsp == NULL)
247 return -ENOMEM;
248
249 sbsp->smk_root = smack_known_floor.smk_known;
250 sbsp->smk_default = smack_known_floor.smk_known;
251 sbsp->smk_floor = smack_known_floor.smk_known;
252 sbsp->smk_hat = smack_known_hat.smk_known;
253 sbsp->smk_initialized = 0;
254
255 sb->s_security = sbsp;
256
257 return 0;
258 }
259
260 /**
261 * smack_sb_free_security - free a superblock blob
262 * @sb: the superblock getting the blob
263 *
264 */
265 static void smack_sb_free_security(struct super_block *sb)
266 {
267 kfree(sb->s_security);
268 sb->s_security = NULL;
269 }
270
271 /**
272 * smack_sb_copy_data - copy mount options data for processing
273 * @orig: where to start
274 * @smackopts: mount options string
275 *
276 * Returns 0 on success or -ENOMEM on error.
277 *
278 * Copy the Smack specific mount options out of the mount
279 * options list.
280 */
281 static int smack_sb_copy_data(char *orig, char *smackopts)
282 {
283 char *cp, *commap, *otheropts, *dp;
284
285 otheropts = (char *)get_zeroed_page(GFP_KERNEL);
286 if (otheropts == NULL)
287 return -ENOMEM;
288
289 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
290 if (strstr(cp, SMK_FSDEFAULT) == cp)
291 dp = smackopts;
292 else if (strstr(cp, SMK_FSFLOOR) == cp)
293 dp = smackopts;
294 else if (strstr(cp, SMK_FSHAT) == cp)
295 dp = smackopts;
296 else if (strstr(cp, SMK_FSROOT) == cp)
297 dp = smackopts;
298 else
299 dp = otheropts;
300
301 commap = strchr(cp, ',');
302 if (commap != NULL)
303 *commap = '\0';
304
305 if (*dp != '\0')
306 strcat(dp, ",");
307 strcat(dp, cp);
308 }
309
310 strcpy(orig, otheropts);
311 free_page((unsigned long)otheropts);
312
313 return 0;
314 }
315
316 /**
317 * smack_sb_kern_mount - Smack specific mount processing
318 * @sb: the file system superblock
319 * @flags: the mount flags
320 * @data: the smack mount options
321 *
322 * Returns 0 on success, an error code on failure
323 */
324 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
325 {
326 struct dentry *root = sb->s_root;
327 struct inode *inode = root->d_inode;
328 struct superblock_smack *sp = sb->s_security;
329 struct inode_smack *isp;
330 char *op;
331 char *commap;
332 char *nsp;
333
334 if (sp->smk_initialized != 0)
335 return 0;
336
337 sp->smk_initialized = 1;
338
339 for (op = data; op != NULL; op = commap) {
340 commap = strchr(op, ',');
341 if (commap != NULL)
342 *commap++ = '\0';
343
344 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
345 op += strlen(SMK_FSHAT);
346 nsp = smk_import(op, 0);
347 if (nsp != NULL)
348 sp->smk_hat = nsp;
349 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
350 op += strlen(SMK_FSFLOOR);
351 nsp = smk_import(op, 0);
352 if (nsp != NULL)
353 sp->smk_floor = nsp;
354 } else if (strncmp(op, SMK_FSDEFAULT,
355 strlen(SMK_FSDEFAULT)) == 0) {
356 op += strlen(SMK_FSDEFAULT);
357 nsp = smk_import(op, 0);
358 if (nsp != NULL)
359 sp->smk_default = nsp;
360 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
361 op += strlen(SMK_FSROOT);
362 nsp = smk_import(op, 0);
363 if (nsp != NULL)
364 sp->smk_root = nsp;
365 }
366 }
367
368 /*
369 * Initialize the root inode.
370 */
371 isp = inode->i_security;
372 if (isp == NULL)
373 inode->i_security = new_inode_smack(sp->smk_root);
374 else
375 isp->smk_inode = sp->smk_root;
376
377 return 0;
378 }
379
380 /**
381 * smack_sb_statfs - Smack check on statfs
382 * @dentry: identifies the file system in question
383 *
384 * Returns 0 if current can read the floor of the filesystem,
385 * and error code otherwise
386 */
387 static int smack_sb_statfs(struct dentry *dentry)
388 {
389 struct superblock_smack *sbp = dentry->d_sb->s_security;
390 int rc;
391 struct smk_audit_info ad;
392
393 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
394 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
395
396 rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
397 return rc;
398 }
399
400 /**
401 * smack_sb_mount - Smack check for mounting
402 * @dev_name: unused
403 * @path: mount point
404 * @type: unused
405 * @flags: unused
406 * @data: unused
407 *
408 * Returns 0 if current can write the floor of the filesystem
409 * being mounted on, an error code otherwise.
410 */
411 static int smack_sb_mount(char *dev_name, struct path *path,
412 char *type, unsigned long flags, void *data)
413 {
414 struct superblock_smack *sbp = path->dentry->d_sb->s_security;
415 struct smk_audit_info ad;
416
417 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
418 smk_ad_setfield_u_fs_path(&ad, *path);
419
420 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
421 }
422
423 /**
424 * smack_sb_umount - Smack check for unmounting
425 * @mnt: file system to unmount
426 * @flags: unused
427 *
428 * Returns 0 if current can write the floor of the filesystem
429 * being unmounted, an error code otherwise.
430 */
431 static int smack_sb_umount(struct vfsmount *mnt, int flags)
432 {
433 struct superblock_smack *sbp;
434 struct smk_audit_info ad;
435 struct path path;
436
437 path.dentry = mnt->mnt_root;
438 path.mnt = mnt;
439
440 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
441 smk_ad_setfield_u_fs_path(&ad, path);
442
443 sbp = path.dentry->d_sb->s_security;
444 return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
445 }
446
447 /*
448 * BPRM hooks
449 */
450
451 /**
452 * smack_bprm_set_creds - set creds for exec
453 * @bprm: the exec information
454 *
455 * Returns 0 if it gets a blob, -ENOMEM otherwise
456 */
457 static int smack_bprm_set_creds(struct linux_binprm *bprm)
458 {
459 struct inode *inode = bprm->file->f_path.dentry->d_inode;
460 struct task_smack *bsp = bprm->cred->security;
461 struct inode_smack *isp;
462 int rc;
463
464 rc = cap_bprm_set_creds(bprm);
465 if (rc != 0)
466 return rc;
467
468 if (bprm->cred_prepared)
469 return 0;
470
471 isp = inode->i_security;
472 if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
473 return 0;
474
475 if (bprm->unsafe)
476 return -EPERM;
477
478 bsp->smk_task = isp->smk_task;
479 bprm->per_clear |= PER_CLEAR_ON_SETID;
480
481 return 0;
482 }
483
484 /**
485 * smack_bprm_committing_creds - Prepare to install the new credentials
486 * from bprm.
487 *
488 * @bprm: binprm for exec
489 */
490 static void smack_bprm_committing_creds(struct linux_binprm *bprm)
491 {
492 struct task_smack *bsp = bprm->cred->security;
493
494 if (bsp->smk_task != bsp->smk_forked)
495 current->pdeath_signal = 0;
496 }
497
498 /**
499 * smack_bprm_secureexec - Return the decision to use secureexec.
500 * @bprm: binprm for exec
501 *
502 * Returns 0 on success.
503 */
504 static int smack_bprm_secureexec(struct linux_binprm *bprm)
505 {
506 struct task_smack *tsp = current_security();
507 int ret = cap_bprm_secureexec(bprm);
508
509 if (!ret && (tsp->smk_task != tsp->smk_forked))
510 ret = 1;
511
512 return ret;
513 }
514
515 /*
516 * Inode hooks
517 */
518
519 /**
520 * smack_inode_alloc_security - allocate an inode blob
521 * @inode: the inode in need of a blob
522 *
523 * Returns 0 if it gets a blob, -ENOMEM otherwise
524 */
525 static int smack_inode_alloc_security(struct inode *inode)
526 {
527 inode->i_security = new_inode_smack(smk_of_current());
528 if (inode->i_security == NULL)
529 return -ENOMEM;
530 return 0;
531 }
532
533 /**
534 * smack_inode_free_security - free an inode blob
535 * @inode: the inode with a blob
536 *
537 * Clears the blob pointer in inode
538 */
539 static void smack_inode_free_security(struct inode *inode)
540 {
541 kfree(inode->i_security);
542 inode->i_security = NULL;
543 }
544
545 /**
546 * smack_inode_init_security - copy out the smack from an inode
547 * @inode: the inode
548 * @dir: unused
549 * @qstr: unused
550 * @name: where to put the attribute name
551 * @value: where to put the attribute value
552 * @len: where to put the length of the attribute
553 *
554 * Returns 0 if it all works out, -ENOMEM if there's no memory
555 */
556 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
557 const struct qstr *qstr, char **name,
558 void **value, size_t *len)
559 {
560 struct smack_known *skp;
561 struct inode_smack *issp = inode->i_security;
562 char *csp = smk_of_current();
563 char *isp = smk_of_inode(inode);
564 char *dsp = smk_of_inode(dir);
565 int may;
566
567 if (name) {
568 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_NOFS);
569 if (*name == NULL)
570 return -ENOMEM;
571 }
572
573 if (value) {
574 skp = smk_find_entry(csp);
575 rcu_read_lock();
576 may = smk_access_entry(csp, dsp, &skp->smk_rules);
577 rcu_read_unlock();
578
579 /*
580 * If the access rule allows transmutation and
581 * the directory requests transmutation then
582 * by all means transmute.
583 * Mark the inode as changed.
584 */
585 if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
586 smk_inode_transmutable(dir)) {
587 isp = dsp;
588 issp->smk_flags |= SMK_INODE_CHANGED;
589 }
590
591 *value = kstrdup(isp, GFP_NOFS);
592 if (*value == NULL)
593 return -ENOMEM;
594 }
595
596 if (len)
597 *len = strlen(isp) + 1;
598
599 return 0;
600 }
601
602 /**
603 * smack_inode_link - Smack check on link
604 * @old_dentry: the existing object
605 * @dir: unused
606 * @new_dentry: the new object
607 *
608 * Returns 0 if access is permitted, an error code otherwise
609 */
610 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
611 struct dentry *new_dentry)
612 {
613 char *isp;
614 struct smk_audit_info ad;
615 int rc;
616
617 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
618 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
619
620 isp = smk_of_inode(old_dentry->d_inode);
621 rc = smk_curacc(isp, MAY_WRITE, &ad);
622
623 if (rc == 0 && new_dentry->d_inode != NULL) {
624 isp = smk_of_inode(new_dentry->d_inode);
625 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
626 rc = smk_curacc(isp, MAY_WRITE, &ad);
627 }
628
629 return rc;
630 }
631
632 /**
633 * smack_inode_unlink - Smack check on inode deletion
634 * @dir: containing directory object
635 * @dentry: file to unlink
636 *
637 * Returns 0 if current can write the containing directory
638 * and the object, error code otherwise
639 */
640 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
641 {
642 struct inode *ip = dentry->d_inode;
643 struct smk_audit_info ad;
644 int rc;
645
646 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
647 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
648
649 /*
650 * You need write access to the thing you're unlinking
651 */
652 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
653 if (rc == 0) {
654 /*
655 * You also need write access to the containing directory
656 */
657 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
658 smk_ad_setfield_u_fs_inode(&ad, dir);
659 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
660 }
661 return rc;
662 }
663
664 /**
665 * smack_inode_rmdir - Smack check on directory deletion
666 * @dir: containing directory object
667 * @dentry: directory to unlink
668 *
669 * Returns 0 if current can write the containing directory
670 * and the directory, error code otherwise
671 */
672 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
673 {
674 struct smk_audit_info ad;
675 int rc;
676
677 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
678 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
679
680 /*
681 * You need write access to the thing you're removing
682 */
683 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
684 if (rc == 0) {
685 /*
686 * You also need write access to the containing directory
687 */
688 smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
689 smk_ad_setfield_u_fs_inode(&ad, dir);
690 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
691 }
692
693 return rc;
694 }
695
696 /**
697 * smack_inode_rename - Smack check on rename
698 * @old_inode: the old directory
699 * @old_dentry: unused
700 * @new_inode: the new directory
701 * @new_dentry: unused
702 *
703 * Read and write access is required on both the old and
704 * new directories.
705 *
706 * Returns 0 if access is permitted, an error code otherwise
707 */
708 static int smack_inode_rename(struct inode *old_inode,
709 struct dentry *old_dentry,
710 struct inode *new_inode,
711 struct dentry *new_dentry)
712 {
713 int rc;
714 char *isp;
715 struct smk_audit_info ad;
716
717 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
718 smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
719
720 isp = smk_of_inode(old_dentry->d_inode);
721 rc = smk_curacc(isp, MAY_READWRITE, &ad);
722
723 if (rc == 0 && new_dentry->d_inode != NULL) {
724 isp = smk_of_inode(new_dentry->d_inode);
725 smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
726 rc = smk_curacc(isp, MAY_READWRITE, &ad);
727 }
728 return rc;
729 }
730
731 /**
732 * smack_inode_permission - Smack version of permission()
733 * @inode: the inode in question
734 * @mask: the access requested
735 *
736 * This is the important Smack hook.
737 *
738 * Returns 0 if access is permitted, -EACCES otherwise
739 */
740 static int smack_inode_permission(struct inode *inode, int mask)
741 {
742 struct smk_audit_info ad;
743 int no_block = mask & MAY_NOT_BLOCK;
744
745 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
746 /*
747 * No permission to check. Existence test. Yup, it's there.
748 */
749 if (mask == 0)
750 return 0;
751
752 /* May be droppable after audit */
753 if (no_block)
754 return -ECHILD;
755 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
756 smk_ad_setfield_u_fs_inode(&ad, inode);
757 return smk_curacc(smk_of_inode(inode), mask, &ad);
758 }
759
760 /**
761 * smack_inode_setattr - Smack check for setting attributes
762 * @dentry: the object
763 * @iattr: for the force flag
764 *
765 * Returns 0 if access is permitted, an error code otherwise
766 */
767 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
768 {
769 struct smk_audit_info ad;
770 /*
771 * Need to allow for clearing the setuid bit.
772 */
773 if (iattr->ia_valid & ATTR_FORCE)
774 return 0;
775 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
776 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
777
778 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
779 }
780
781 /**
782 * smack_inode_getattr - Smack check for getting attributes
783 * @mnt: unused
784 * @dentry: the object
785 *
786 * Returns 0 if access is permitted, an error code otherwise
787 */
788 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
789 {
790 struct smk_audit_info ad;
791 struct path path;
792
793 path.dentry = dentry;
794 path.mnt = mnt;
795
796 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
797 smk_ad_setfield_u_fs_path(&ad, path);
798 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
799 }
800
801 /**
802 * smack_inode_setxattr - Smack check for setting xattrs
803 * @dentry: the object
804 * @name: name of the attribute
805 * @value: unused
806 * @size: unused
807 * @flags: unused
808 *
809 * This protects the Smack attribute explicitly.
810 *
811 * Returns 0 if access is permitted, an error code otherwise
812 */
813 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
814 const void *value, size_t size, int flags)
815 {
816 struct smk_audit_info ad;
817 int rc = 0;
818
819 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
820 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
821 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
822 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
823 strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
824 if (!smack_privileged(CAP_MAC_ADMIN))
825 rc = -EPERM;
826 /*
827 * check label validity here so import wont fail on
828 * post_setxattr
829 */
830 if (size == 0 || size >= SMK_LONGLABEL ||
831 smk_import(value, size) == NULL)
832 rc = -EINVAL;
833 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
834 if (!smack_privileged(CAP_MAC_ADMIN))
835 rc = -EPERM;
836 if (size != TRANS_TRUE_SIZE ||
837 strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
838 rc = -EINVAL;
839 } else
840 rc = cap_inode_setxattr(dentry, name, value, size, flags);
841
842 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
843 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
844
845 if (rc == 0)
846 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
847
848 return rc;
849 }
850
851 /**
852 * smack_inode_post_setxattr - Apply the Smack update approved above
853 * @dentry: object
854 * @name: attribute name
855 * @value: attribute value
856 * @size: attribute size
857 * @flags: unused
858 *
859 * Set the pointer in the inode blob to the entry found
860 * in the master label list.
861 */
862 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
863 const void *value, size_t size, int flags)
864 {
865 char *nsp;
866 struct inode_smack *isp = dentry->d_inode->i_security;
867
868 if (strcmp(name, XATTR_NAME_SMACK) == 0) {
869 nsp = smk_import(value, size);
870 if (nsp != NULL)
871 isp->smk_inode = nsp;
872 else
873 isp->smk_inode = smack_known_invalid.smk_known;
874 } else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
875 nsp = smk_import(value, size);
876 if (nsp != NULL)
877 isp->smk_task = nsp;
878 else
879 isp->smk_task = smack_known_invalid.smk_known;
880 } else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
881 nsp = smk_import(value, size);
882 if (nsp != NULL)
883 isp->smk_mmap = nsp;
884 else
885 isp->smk_mmap = smack_known_invalid.smk_known;
886 } else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
887 isp->smk_flags |= SMK_INODE_TRANSMUTE;
888
889 return;
890 }
891
892 /**
893 * smack_inode_getxattr - Smack check on getxattr
894 * @dentry: the object
895 * @name: unused
896 *
897 * Returns 0 if access is permitted, an error code otherwise
898 */
899 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
900 {
901 struct smk_audit_info ad;
902
903 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
904 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
905
906 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
907 }
908
909 /**
910 * smack_inode_removexattr - Smack check on removexattr
911 * @dentry: the object
912 * @name: name of the attribute
913 *
914 * Removing the Smack attribute requires CAP_MAC_ADMIN
915 *
916 * Returns 0 if access is permitted, an error code otherwise
917 */
918 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
919 {
920 struct inode_smack *isp;
921 struct smk_audit_info ad;
922 int rc = 0;
923
924 if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
925 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
926 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
927 strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
928 strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
929 strcmp(name, XATTR_NAME_SMACKMMAP)) {
930 if (!smack_privileged(CAP_MAC_ADMIN))
931 rc = -EPERM;
932 } else
933 rc = cap_inode_removexattr(dentry, name);
934
935 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
936 smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
937 if (rc == 0)
938 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
939
940 if (rc == 0) {
941 isp = dentry->d_inode->i_security;
942 isp->smk_task = NULL;
943 isp->smk_mmap = NULL;
944 }
945
946 return rc;
947 }
948
949 /**
950 * smack_inode_getsecurity - get smack xattrs
951 * @inode: the object
952 * @name: attribute name
953 * @buffer: where to put the result
954 * @alloc: unused
955 *
956 * Returns the size of the attribute or an error code
957 */
958 static int smack_inode_getsecurity(const struct inode *inode,
959 const char *name, void **buffer,
960 bool alloc)
961 {
962 struct socket_smack *ssp;
963 struct socket *sock;
964 struct super_block *sbp;
965 struct inode *ip = (struct inode *)inode;
966 char *isp;
967 int ilen;
968 int rc = 0;
969
970 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
971 isp = smk_of_inode(inode);
972 ilen = strlen(isp) + 1;
973 *buffer = isp;
974 return ilen;
975 }
976
977 /*
978 * The rest of the Smack xattrs are only on sockets.
979 */
980 sbp = ip->i_sb;
981 if (sbp->s_magic != SOCKFS_MAGIC)
982 return -EOPNOTSUPP;
983
984 sock = SOCKET_I(ip);
985 if (sock == NULL || sock->sk == NULL)
986 return -EOPNOTSUPP;
987
988 ssp = sock->sk->sk_security;
989
990 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
991 isp = ssp->smk_in;
992 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
993 isp = ssp->smk_out;
994 else
995 return -EOPNOTSUPP;
996
997 ilen = strlen(isp) + 1;
998 if (rc == 0) {
999 *buffer = isp;
1000 rc = ilen;
1001 }
1002
1003 return rc;
1004 }
1005
1006
1007 /**
1008 * smack_inode_listsecurity - list the Smack attributes
1009 * @inode: the object
1010 * @buffer: where they go
1011 * @buffer_size: size of buffer
1012 *
1013 * Returns 0 on success, -EINVAL otherwise
1014 */
1015 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1016 size_t buffer_size)
1017 {
1018 int len = strlen(XATTR_NAME_SMACK);
1019
1020 if (buffer != NULL && len <= buffer_size) {
1021 memcpy(buffer, XATTR_NAME_SMACK, len);
1022 return len;
1023 }
1024 return -EINVAL;
1025 }
1026
1027 /**
1028 * smack_inode_getsecid - Extract inode's security id
1029 * @inode: inode to extract the info from
1030 * @secid: where result will be saved
1031 */
1032 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1033 {
1034 struct inode_smack *isp = inode->i_security;
1035
1036 *secid = smack_to_secid(isp->smk_inode);
1037 }
1038
1039 /*
1040 * File Hooks
1041 */
1042
1043 /**
1044 * smack_file_permission - Smack check on file operations
1045 * @file: unused
1046 * @mask: unused
1047 *
1048 * Returns 0
1049 *
1050 * Should access checks be done on each read or write?
1051 * UNICOS and SELinux say yes.
1052 * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1053 *
1054 * I'll say no for now. Smack does not do the frequent
1055 * label changing that SELinux does.
1056 */
1057 static int smack_file_permission(struct file *file, int mask)
1058 {
1059 return 0;
1060 }
1061
1062 /**
1063 * smack_file_alloc_security - assign a file security blob
1064 * @file: the object
1065 *
1066 * The security blob for a file is a pointer to the master
1067 * label list, so no allocation is done.
1068 *
1069 * Returns 0
1070 */
1071 static int smack_file_alloc_security(struct file *file)
1072 {
1073 file->f_security = smk_of_current();
1074 return 0;
1075 }
1076
1077 /**
1078 * smack_file_free_security - clear a file security blob
1079 * @file: the object
1080 *
1081 * The security blob for a file is a pointer to the master
1082 * label list, so no memory is freed.
1083 */
1084 static void smack_file_free_security(struct file *file)
1085 {
1086 file->f_security = NULL;
1087 }
1088
1089 /**
1090 * smack_file_ioctl - Smack check on ioctls
1091 * @file: the object
1092 * @cmd: what to do
1093 * @arg: unused
1094 *
1095 * Relies heavily on the correct use of the ioctl command conventions.
1096 *
1097 * Returns 0 if allowed, error code otherwise
1098 */
1099 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1100 unsigned long arg)
1101 {
1102 int rc = 0;
1103 struct smk_audit_info ad;
1104
1105 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1106 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1107
1108 if (_IOC_DIR(cmd) & _IOC_WRITE)
1109 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1110
1111 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1112 rc = smk_curacc(file->f_security, MAY_READ, &ad);
1113
1114 return rc;
1115 }
1116
1117 /**
1118 * smack_file_lock - Smack check on file locking
1119 * @file: the object
1120 * @cmd: unused
1121 *
1122 * Returns 0 if current has write access, error code otherwise
1123 */
1124 static int smack_file_lock(struct file *file, unsigned int cmd)
1125 {
1126 struct smk_audit_info ad;
1127
1128 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1129 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1130 return smk_curacc(file->f_security, MAY_WRITE, &ad);
1131 }
1132
1133 /**
1134 * smack_file_fcntl - Smack check on fcntl
1135 * @file: the object
1136 * @cmd: what action to check
1137 * @arg: unused
1138 *
1139 * Generally these operations are harmless.
1140 * File locking operations present an obvious mechanism
1141 * for passing information, so they require write access.
1142 *
1143 * Returns 0 if current has access, error code otherwise
1144 */
1145 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1146 unsigned long arg)
1147 {
1148 struct smk_audit_info ad;
1149 int rc = 0;
1150
1151
1152 switch (cmd) {
1153 case F_GETLK:
1154 case F_SETLK:
1155 case F_SETLKW:
1156 case F_SETOWN:
1157 case F_SETSIG:
1158 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1159 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1160 rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1161 break;
1162 default:
1163 break;
1164 }
1165
1166 return rc;
1167 }
1168
1169 /**
1170 * smack_mmap_file :
1171 * Check permissions for a mmap operation. The @file may be NULL, e.g.
1172 * if mapping anonymous memory.
1173 * @file contains the file structure for file to map (may be NULL).
1174 * @reqprot contains the protection requested by the application.
1175 * @prot contains the protection that will be applied by the kernel.
1176 * @flags contains the operational flags.
1177 * Return 0 if permission is granted.
1178 */
1179 static int smack_mmap_file(struct file *file,
1180 unsigned long reqprot, unsigned long prot,
1181 unsigned long flags)
1182 {
1183 struct smack_known *skp;
1184 struct smack_rule *srp;
1185 struct task_smack *tsp;
1186 char *sp;
1187 char *msmack;
1188 char *osmack;
1189 struct inode_smack *isp;
1190 struct dentry *dp;
1191 int may;
1192 int mmay;
1193 int tmay;
1194 int 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_file_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_file_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 (smack_privileged(CAP_MAC_OVERRIDE) ||
1720 has_capability(p, CAP_MAC_OVERRIDE))
1721 rc = 0;
1722 /* we log only if we didn't get overriden */
1723 out_log:
1724 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1725 smk_ad_setfield_u_tsk(&ad, p);
1726 smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1727 return rc;
1728 }
1729
1730 /**
1731 * smack_task_to_inode - copy task smack into the inode blob
1732 * @p: task to copy from
1733 * @inode: inode to copy to
1734 *
1735 * Sets the smack pointer in the inode security blob
1736 */
1737 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1738 {
1739 struct inode_smack *isp = inode->i_security;
1740 isp->smk_inode = smk_of_task(task_security(p));
1741 }
1742
1743 /*
1744 * Socket hooks.
1745 */
1746
1747 /**
1748 * smack_sk_alloc_security - Allocate a socket blob
1749 * @sk: the socket
1750 * @family: unused
1751 * @gfp_flags: memory allocation flags
1752 *
1753 * Assign Smack pointers to current
1754 *
1755 * Returns 0 on success, -ENOMEM is there's no memory
1756 */
1757 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1758 {
1759 char *csp = smk_of_current();
1760 struct socket_smack *ssp;
1761
1762 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1763 if (ssp == NULL)
1764 return -ENOMEM;
1765
1766 ssp->smk_in = csp;
1767 ssp->smk_out = csp;
1768 ssp->smk_packet = NULL;
1769
1770 sk->sk_security = ssp;
1771
1772 return 0;
1773 }
1774
1775 /**
1776 * smack_sk_free_security - Free a socket blob
1777 * @sk: the socket
1778 *
1779 * Clears the blob pointer
1780 */
1781 static void smack_sk_free_security(struct sock *sk)
1782 {
1783 kfree(sk->sk_security);
1784 }
1785
1786 /**
1787 * smack_host_label - check host based restrictions
1788 * @sip: the object end
1789 *
1790 * looks for host based access restrictions
1791 *
1792 * This version will only be appropriate for really small sets of single label
1793 * hosts. The caller is responsible for ensuring that the RCU read lock is
1794 * taken before calling this function.
1795 *
1796 * Returns the label of the far end or NULL if it's not special.
1797 */
1798 static char *smack_host_label(struct sockaddr_in *sip)
1799 {
1800 struct smk_netlbladdr *snp;
1801 struct in_addr *siap = &sip->sin_addr;
1802
1803 if (siap->s_addr == 0)
1804 return NULL;
1805
1806 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1807 /*
1808 * we break after finding the first match because
1809 * the list is sorted from longest to shortest mask
1810 * so we have found the most specific match
1811 */
1812 if ((&snp->smk_host.sin_addr)->s_addr ==
1813 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1814 /* we have found the special CIPSO option */
1815 if (snp->smk_label == smack_cipso_option)
1816 return NULL;
1817 return snp->smk_label;
1818 }
1819
1820 return NULL;
1821 }
1822
1823 /**
1824 * smack_netlabel - Set the secattr on a socket
1825 * @sk: the socket
1826 * @labeled: socket label scheme
1827 *
1828 * Convert the outbound smack value (smk_out) to a
1829 * secattr and attach it to the socket.
1830 *
1831 * Returns 0 on success or an error code
1832 */
1833 static int smack_netlabel(struct sock *sk, int labeled)
1834 {
1835 struct smack_known *skp;
1836 struct socket_smack *ssp = sk->sk_security;
1837 int rc = 0;
1838
1839 /*
1840 * Usually the netlabel code will handle changing the
1841 * packet labeling based on the label.
1842 * The case of a single label host is different, because
1843 * a single label host should never get a labeled packet
1844 * even though the label is usually associated with a packet
1845 * label.
1846 */
1847 local_bh_disable();
1848 bh_lock_sock_nested(sk);
1849
1850 if (ssp->smk_out == smack_net_ambient ||
1851 labeled == SMACK_UNLABELED_SOCKET)
1852 netlbl_sock_delattr(sk);
1853 else {
1854 skp = smk_find_entry(ssp->smk_out);
1855 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
1856 }
1857
1858 bh_unlock_sock(sk);
1859 local_bh_enable();
1860
1861 return rc;
1862 }
1863
1864 /**
1865 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1866 * @sk: the socket
1867 * @sap: the destination address
1868 *
1869 * Set the correct secattr for the given socket based on the destination
1870 * address and perform any outbound access checks needed.
1871 *
1872 * Returns 0 on success or an error code.
1873 *
1874 */
1875 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1876 {
1877 int rc;
1878 int sk_lbl;
1879 char *hostsp;
1880 struct socket_smack *ssp = sk->sk_security;
1881 struct smk_audit_info ad;
1882
1883 rcu_read_lock();
1884 hostsp = smack_host_label(sap);
1885 if (hostsp != NULL) {
1886 #ifdef CONFIG_AUDIT
1887 struct lsm_network_audit net;
1888
1889 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1890 ad.a.u.net->family = sap->sin_family;
1891 ad.a.u.net->dport = sap->sin_port;
1892 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1893 #endif
1894 sk_lbl = SMACK_UNLABELED_SOCKET;
1895 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1896 } else {
1897 sk_lbl = SMACK_CIPSO_SOCKET;
1898 rc = 0;
1899 }
1900 rcu_read_unlock();
1901 if (rc != 0)
1902 return rc;
1903
1904 return smack_netlabel(sk, sk_lbl);
1905 }
1906
1907 /**
1908 * smack_inode_setsecurity - set smack xattrs
1909 * @inode: the object
1910 * @name: attribute name
1911 * @value: attribute value
1912 * @size: size of the attribute
1913 * @flags: unused
1914 *
1915 * Sets the named attribute in the appropriate blob
1916 *
1917 * Returns 0 on success, or an error code
1918 */
1919 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1920 const void *value, size_t size, int flags)
1921 {
1922 char *sp;
1923 struct inode_smack *nsp = inode->i_security;
1924 struct socket_smack *ssp;
1925 struct socket *sock;
1926 int rc = 0;
1927
1928 if (value == NULL || size > SMK_LONGLABEL || size == 0)
1929 return -EACCES;
1930
1931 sp = smk_import(value, size);
1932 if (sp == NULL)
1933 return -EINVAL;
1934
1935 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1936 nsp->smk_inode = sp;
1937 nsp->smk_flags |= SMK_INODE_INSTANT;
1938 return 0;
1939 }
1940 /*
1941 * The rest of the Smack xattrs are only on sockets.
1942 */
1943 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1944 return -EOPNOTSUPP;
1945
1946 sock = SOCKET_I(inode);
1947 if (sock == NULL || sock->sk == NULL)
1948 return -EOPNOTSUPP;
1949
1950 ssp = sock->sk->sk_security;
1951
1952 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1953 ssp->smk_in = sp;
1954 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1955 ssp->smk_out = sp;
1956 if (sock->sk->sk_family != PF_UNIX) {
1957 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1958 if (rc != 0)
1959 printk(KERN_WARNING
1960 "Smack: \"%s\" netlbl error %d.\n",
1961 __func__, -rc);
1962 }
1963 } else
1964 return -EOPNOTSUPP;
1965
1966 return 0;
1967 }
1968
1969 /**
1970 * smack_socket_post_create - finish socket setup
1971 * @sock: the socket
1972 * @family: protocol family
1973 * @type: unused
1974 * @protocol: unused
1975 * @kern: unused
1976 *
1977 * Sets the netlabel information on the socket
1978 *
1979 * Returns 0 on success, and error code otherwise
1980 */
1981 static int smack_socket_post_create(struct socket *sock, int family,
1982 int type, int protocol, int kern)
1983 {
1984 if (family != PF_INET || sock->sk == NULL)
1985 return 0;
1986 /*
1987 * Set the outbound netlbl.
1988 */
1989 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1990 }
1991
1992 /**
1993 * smack_socket_connect - connect access check
1994 * @sock: the socket
1995 * @sap: the other end
1996 * @addrlen: size of sap
1997 *
1998 * Verifies that a connection may be possible
1999 *
2000 * Returns 0 on success, and error code otherwise
2001 */
2002 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2003 int addrlen)
2004 {
2005 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2006 return 0;
2007 if (addrlen < sizeof(struct sockaddr_in))
2008 return -EINVAL;
2009
2010 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2011 }
2012
2013 /**
2014 * smack_flags_to_may - convert S_ to MAY_ values
2015 * @flags: the S_ value
2016 *
2017 * Returns the equivalent MAY_ value
2018 */
2019 static int smack_flags_to_may(int flags)
2020 {
2021 int may = 0;
2022
2023 if (flags & S_IRUGO)
2024 may |= MAY_READ;
2025 if (flags & S_IWUGO)
2026 may |= MAY_WRITE;
2027 if (flags & S_IXUGO)
2028 may |= MAY_EXEC;
2029
2030 return may;
2031 }
2032
2033 /**
2034 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2035 * @msg: the object
2036 *
2037 * Returns 0
2038 */
2039 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2040 {
2041 msg->security = smk_of_current();
2042 return 0;
2043 }
2044
2045 /**
2046 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2047 * @msg: the object
2048 *
2049 * Clears the blob pointer
2050 */
2051 static void smack_msg_msg_free_security(struct msg_msg *msg)
2052 {
2053 msg->security = NULL;
2054 }
2055
2056 /**
2057 * smack_of_shm - the smack pointer for the shm
2058 * @shp: the object
2059 *
2060 * Returns a pointer to the smack value
2061 */
2062 static char *smack_of_shm(struct shmid_kernel *shp)
2063 {
2064 return (char *)shp->shm_perm.security;
2065 }
2066
2067 /**
2068 * smack_shm_alloc_security - Set the security blob for shm
2069 * @shp: the object
2070 *
2071 * Returns 0
2072 */
2073 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2074 {
2075 struct kern_ipc_perm *isp = &shp->shm_perm;
2076
2077 isp->security = smk_of_current();
2078 return 0;
2079 }
2080
2081 /**
2082 * smack_shm_free_security - Clear the security blob for shm
2083 * @shp: the object
2084 *
2085 * Clears the blob pointer
2086 */
2087 static void smack_shm_free_security(struct shmid_kernel *shp)
2088 {
2089 struct kern_ipc_perm *isp = &shp->shm_perm;
2090
2091 isp->security = NULL;
2092 }
2093
2094 /**
2095 * smk_curacc_shm : check if current has access on shm
2096 * @shp : the object
2097 * @access : access requested
2098 *
2099 * Returns 0 if current has the requested access, error code otherwise
2100 */
2101 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2102 {
2103 char *ssp = smack_of_shm(shp);
2104 struct smk_audit_info ad;
2105
2106 #ifdef CONFIG_AUDIT
2107 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2108 ad.a.u.ipc_id = shp->shm_perm.id;
2109 #endif
2110 return smk_curacc(ssp, access, &ad);
2111 }
2112
2113 /**
2114 * smack_shm_associate - Smack access check for shm
2115 * @shp: the object
2116 * @shmflg: access requested
2117 *
2118 * Returns 0 if current has the requested access, error code otherwise
2119 */
2120 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2121 {
2122 int may;
2123
2124 may = smack_flags_to_may(shmflg);
2125 return smk_curacc_shm(shp, may);
2126 }
2127
2128 /**
2129 * smack_shm_shmctl - Smack access check for shm
2130 * @shp: the object
2131 * @cmd: what it wants to do
2132 *
2133 * Returns 0 if current has the requested access, error code otherwise
2134 */
2135 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2136 {
2137 int may;
2138
2139 switch (cmd) {
2140 case IPC_STAT:
2141 case SHM_STAT:
2142 may = MAY_READ;
2143 break;
2144 case IPC_SET:
2145 case SHM_LOCK:
2146 case SHM_UNLOCK:
2147 case IPC_RMID:
2148 may = MAY_READWRITE;
2149 break;
2150 case IPC_INFO:
2151 case SHM_INFO:
2152 /*
2153 * System level information.
2154 */
2155 return 0;
2156 default:
2157 return -EINVAL;
2158 }
2159 return smk_curacc_shm(shp, may);
2160 }
2161
2162 /**
2163 * smack_shm_shmat - Smack access for shmat
2164 * @shp: the object
2165 * @shmaddr: unused
2166 * @shmflg: access requested
2167 *
2168 * Returns 0 if current has the requested access, error code otherwise
2169 */
2170 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2171 int shmflg)
2172 {
2173 int may;
2174
2175 may = smack_flags_to_may(shmflg);
2176 return smk_curacc_shm(shp, may);
2177 }
2178
2179 /**
2180 * smack_of_sem - the smack pointer for the sem
2181 * @sma: the object
2182 *
2183 * Returns a pointer to the smack value
2184 */
2185 static char *smack_of_sem(struct sem_array *sma)
2186 {
2187 return (char *)sma->sem_perm.security;
2188 }
2189
2190 /**
2191 * smack_sem_alloc_security - Set the security blob for sem
2192 * @sma: the object
2193 *
2194 * Returns 0
2195 */
2196 static int smack_sem_alloc_security(struct sem_array *sma)
2197 {
2198 struct kern_ipc_perm *isp = &sma->sem_perm;
2199
2200 isp->security = smk_of_current();
2201 return 0;
2202 }
2203
2204 /**
2205 * smack_sem_free_security - Clear the security blob for sem
2206 * @sma: the object
2207 *
2208 * Clears the blob pointer
2209 */
2210 static void smack_sem_free_security(struct sem_array *sma)
2211 {
2212 struct kern_ipc_perm *isp = &sma->sem_perm;
2213
2214 isp->security = NULL;
2215 }
2216
2217 /**
2218 * smk_curacc_sem : check if current has access on sem
2219 * @sma : the object
2220 * @access : access requested
2221 *
2222 * Returns 0 if current has the requested access, error code otherwise
2223 */
2224 static int smk_curacc_sem(struct sem_array *sma, int access)
2225 {
2226 char *ssp = smack_of_sem(sma);
2227 struct smk_audit_info ad;
2228
2229 #ifdef CONFIG_AUDIT
2230 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2231 ad.a.u.ipc_id = sma->sem_perm.id;
2232 #endif
2233 return smk_curacc(ssp, access, &ad);
2234 }
2235
2236 /**
2237 * smack_sem_associate - Smack access check for sem
2238 * @sma: the object
2239 * @semflg: access requested
2240 *
2241 * Returns 0 if current has the requested access, error code otherwise
2242 */
2243 static int smack_sem_associate(struct sem_array *sma, int semflg)
2244 {
2245 int may;
2246
2247 may = smack_flags_to_may(semflg);
2248 return smk_curacc_sem(sma, may);
2249 }
2250
2251 /**
2252 * smack_sem_shmctl - Smack access check for sem
2253 * @sma: the object
2254 * @cmd: what it wants to do
2255 *
2256 * Returns 0 if current has the requested access, error code otherwise
2257 */
2258 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2259 {
2260 int may;
2261
2262 switch (cmd) {
2263 case GETPID:
2264 case GETNCNT:
2265 case GETZCNT:
2266 case GETVAL:
2267 case GETALL:
2268 case IPC_STAT:
2269 case SEM_STAT:
2270 may = MAY_READ;
2271 break;
2272 case SETVAL:
2273 case SETALL:
2274 case IPC_RMID:
2275 case IPC_SET:
2276 may = MAY_READWRITE;
2277 break;
2278 case IPC_INFO:
2279 case SEM_INFO:
2280 /*
2281 * System level information
2282 */
2283 return 0;
2284 default:
2285 return -EINVAL;
2286 }
2287
2288 return smk_curacc_sem(sma, may);
2289 }
2290
2291 /**
2292 * smack_sem_semop - Smack checks of semaphore operations
2293 * @sma: the object
2294 * @sops: unused
2295 * @nsops: unused
2296 * @alter: unused
2297 *
2298 * Treated as read and write in all cases.
2299 *
2300 * Returns 0 if access is allowed, error code otherwise
2301 */
2302 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2303 unsigned nsops, int alter)
2304 {
2305 return smk_curacc_sem(sma, MAY_READWRITE);
2306 }
2307
2308 /**
2309 * smack_msg_alloc_security - Set the security blob for msg
2310 * @msq: the object
2311 *
2312 * Returns 0
2313 */
2314 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2315 {
2316 struct kern_ipc_perm *kisp = &msq->q_perm;
2317
2318 kisp->security = smk_of_current();
2319 return 0;
2320 }
2321
2322 /**
2323 * smack_msg_free_security - Clear the security blob for msg
2324 * @msq: the object
2325 *
2326 * Clears the blob pointer
2327 */
2328 static void smack_msg_queue_free_security(struct msg_queue *msq)
2329 {
2330 struct kern_ipc_perm *kisp = &msq->q_perm;
2331
2332 kisp->security = NULL;
2333 }
2334
2335 /**
2336 * smack_of_msq - the smack pointer for the msq
2337 * @msq: the object
2338 *
2339 * Returns a pointer to the smack value
2340 */
2341 static char *smack_of_msq(struct msg_queue *msq)
2342 {
2343 return (char *)msq->q_perm.security;
2344 }
2345
2346 /**
2347 * smk_curacc_msq : helper to check if current has access on msq
2348 * @msq : the msq
2349 * @access : access requested
2350 *
2351 * return 0 if current has access, error otherwise
2352 */
2353 static int smk_curacc_msq(struct msg_queue *msq, int access)
2354 {
2355 char *msp = smack_of_msq(msq);
2356 struct smk_audit_info ad;
2357
2358 #ifdef CONFIG_AUDIT
2359 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2360 ad.a.u.ipc_id = msq->q_perm.id;
2361 #endif
2362 return smk_curacc(msp, access, &ad);
2363 }
2364
2365 /**
2366 * smack_msg_queue_associate - Smack access check for msg_queue
2367 * @msq: the object
2368 * @msqflg: access requested
2369 *
2370 * Returns 0 if current has the requested access, error code otherwise
2371 */
2372 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2373 {
2374 int may;
2375
2376 may = smack_flags_to_may(msqflg);
2377 return smk_curacc_msq(msq, may);
2378 }
2379
2380 /**
2381 * smack_msg_queue_msgctl - Smack access check for msg_queue
2382 * @msq: the object
2383 * @cmd: what it wants to do
2384 *
2385 * Returns 0 if current has the requested access, error code otherwise
2386 */
2387 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2388 {
2389 int may;
2390
2391 switch (cmd) {
2392 case IPC_STAT:
2393 case MSG_STAT:
2394 may = MAY_READ;
2395 break;
2396 case IPC_SET:
2397 case IPC_RMID:
2398 may = MAY_READWRITE;
2399 break;
2400 case IPC_INFO:
2401 case MSG_INFO:
2402 /*
2403 * System level information
2404 */
2405 return 0;
2406 default:
2407 return -EINVAL;
2408 }
2409
2410 return smk_curacc_msq(msq, may);
2411 }
2412
2413 /**
2414 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2415 * @msq: the object
2416 * @msg: unused
2417 * @msqflg: access requested
2418 *
2419 * Returns 0 if current has the requested access, error code otherwise
2420 */
2421 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2422 int msqflg)
2423 {
2424 int may;
2425
2426 may = smack_flags_to_may(msqflg);
2427 return smk_curacc_msq(msq, may);
2428 }
2429
2430 /**
2431 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2432 * @msq: the object
2433 * @msg: unused
2434 * @target: unused
2435 * @type: unused
2436 * @mode: unused
2437 *
2438 * Returns 0 if current has read and write access, error code otherwise
2439 */
2440 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2441 struct task_struct *target, long type, int mode)
2442 {
2443 return smk_curacc_msq(msq, MAY_READWRITE);
2444 }
2445
2446 /**
2447 * smack_ipc_permission - Smack access for ipc_permission()
2448 * @ipp: the object permissions
2449 * @flag: access requested
2450 *
2451 * Returns 0 if current has read and write access, error code otherwise
2452 */
2453 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2454 {
2455 char *isp = ipp->security;
2456 int may = smack_flags_to_may(flag);
2457 struct smk_audit_info ad;
2458
2459 #ifdef CONFIG_AUDIT
2460 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2461 ad.a.u.ipc_id = ipp->id;
2462 #endif
2463 return smk_curacc(isp, may, &ad);
2464 }
2465
2466 /**
2467 * smack_ipc_getsecid - Extract smack security id
2468 * @ipp: the object permissions
2469 * @secid: where result will be saved
2470 */
2471 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2472 {
2473 char *smack = ipp->security;
2474
2475 *secid = smack_to_secid(smack);
2476 }
2477
2478 /**
2479 * smack_d_instantiate - Make sure the blob is correct on an inode
2480 * @opt_dentry: dentry where inode will be attached
2481 * @inode: the object
2482 *
2483 * Set the inode's security blob if it hasn't been done already.
2484 */
2485 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2486 {
2487 struct super_block *sbp;
2488 struct superblock_smack *sbsp;
2489 struct inode_smack *isp;
2490 char *csp = smk_of_current();
2491 char *fetched;
2492 char *final;
2493 char trattr[TRANS_TRUE_SIZE];
2494 int transflag = 0;
2495 int rc;
2496 struct dentry *dp;
2497
2498 if (inode == NULL)
2499 return;
2500
2501 isp = inode->i_security;
2502
2503 mutex_lock(&isp->smk_lock);
2504 /*
2505 * If the inode is already instantiated
2506 * take the quick way out
2507 */
2508 if (isp->smk_flags & SMK_INODE_INSTANT)
2509 goto unlockandout;
2510
2511 sbp = inode->i_sb;
2512 sbsp = sbp->s_security;
2513 /*
2514 * We're going to use the superblock default label
2515 * if there's no label on the file.
2516 */
2517 final = sbsp->smk_default;
2518
2519 /*
2520 * If this is the root inode the superblock
2521 * may be in the process of initialization.
2522 * If that is the case use the root value out
2523 * of the superblock.
2524 */
2525 if (opt_dentry->d_parent == opt_dentry) {
2526 isp->smk_inode = sbsp->smk_root;
2527 isp->smk_flags |= SMK_INODE_INSTANT;
2528 goto unlockandout;
2529 }
2530
2531 /*
2532 * This is pretty hackish.
2533 * Casey says that we shouldn't have to do
2534 * file system specific code, but it does help
2535 * with keeping it simple.
2536 */
2537 switch (sbp->s_magic) {
2538 case SMACK_MAGIC:
2539 /*
2540 * Casey says that it's a little embarrassing
2541 * that the smack file system doesn't do
2542 * extended attributes.
2543 */
2544 final = smack_known_star.smk_known;
2545 break;
2546 case PIPEFS_MAGIC:
2547 /*
2548 * Casey says pipes are easy (?)
2549 */
2550 final = smack_known_star.smk_known;
2551 break;
2552 case DEVPTS_SUPER_MAGIC:
2553 /*
2554 * devpts seems content with the label of the task.
2555 * Programs that change smack have to treat the
2556 * pty with respect.
2557 */
2558 final = csp;
2559 break;
2560 case SOCKFS_MAGIC:
2561 /*
2562 * Socket access is controlled by the socket
2563 * structures associated with the task involved.
2564 */
2565 final = smack_known_star.smk_known;
2566 break;
2567 case PROC_SUPER_MAGIC:
2568 /*
2569 * Casey says procfs appears not to care.
2570 * The superblock default suffices.
2571 */
2572 break;
2573 case TMPFS_MAGIC:
2574 /*
2575 * Device labels should come from the filesystem,
2576 * but watch out, because they're volitile,
2577 * getting recreated on every reboot.
2578 */
2579 final = smack_known_star.smk_known;
2580 /*
2581 * No break.
2582 *
2583 * If a smack value has been set we want to use it,
2584 * but since tmpfs isn't giving us the opportunity
2585 * to set mount options simulate setting the
2586 * superblock default.
2587 */
2588 default:
2589 /*
2590 * This isn't an understood special case.
2591 * Get the value from the xattr.
2592 */
2593
2594 /*
2595 * UNIX domain sockets use lower level socket data.
2596 */
2597 if (S_ISSOCK(inode->i_mode)) {
2598 final = smack_known_star.smk_known;
2599 break;
2600 }
2601 /*
2602 * No xattr support means, alas, no SMACK label.
2603 * Use the aforeapplied default.
2604 * It would be curious if the label of the task
2605 * does not match that assigned.
2606 */
2607 if (inode->i_op->getxattr == NULL)
2608 break;
2609 /*
2610 * Get the dentry for xattr.
2611 */
2612 dp = dget(opt_dentry);
2613 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2614 if (fetched != NULL)
2615 final = fetched;
2616
2617 /*
2618 * Transmuting directory
2619 */
2620 if (S_ISDIR(inode->i_mode)) {
2621 /*
2622 * If this is a new directory and the label was
2623 * transmuted when the inode was initialized
2624 * set the transmute attribute on the directory
2625 * and mark the inode.
2626 *
2627 * If there is a transmute attribute on the
2628 * directory mark the inode.
2629 */
2630 if (isp->smk_flags & SMK_INODE_CHANGED) {
2631 isp->smk_flags &= ~SMK_INODE_CHANGED;
2632 rc = inode->i_op->setxattr(dp,
2633 XATTR_NAME_SMACKTRANSMUTE,
2634 TRANS_TRUE, TRANS_TRUE_SIZE,
2635 0);
2636 } else {
2637 rc = inode->i_op->getxattr(dp,
2638 XATTR_NAME_SMACKTRANSMUTE, trattr,
2639 TRANS_TRUE_SIZE);
2640 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
2641 TRANS_TRUE_SIZE) != 0)
2642 rc = -EINVAL;
2643 }
2644 if (rc >= 0)
2645 transflag = SMK_INODE_TRANSMUTE;
2646 }
2647 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2648 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2649
2650 dput(dp);
2651 break;
2652 }
2653
2654 if (final == NULL)
2655 isp->smk_inode = csp;
2656 else
2657 isp->smk_inode = final;
2658
2659 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2660
2661 unlockandout:
2662 mutex_unlock(&isp->smk_lock);
2663 return;
2664 }
2665
2666 /**
2667 * smack_getprocattr - Smack process attribute access
2668 * @p: the object task
2669 * @name: the name of the attribute in /proc/.../attr
2670 * @value: where to put the result
2671 *
2672 * Places a copy of the task Smack into value
2673 *
2674 * Returns the length of the smack label or an error code
2675 */
2676 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2677 {
2678 char *cp;
2679 int slen;
2680
2681 if (strcmp(name, "current") != 0)
2682 return -EINVAL;
2683
2684 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2685 if (cp == NULL)
2686 return -ENOMEM;
2687
2688 slen = strlen(cp);
2689 *value = cp;
2690 return slen;
2691 }
2692
2693 /**
2694 * smack_setprocattr - Smack process attribute setting
2695 * @p: the object task
2696 * @name: the name of the attribute in /proc/.../attr
2697 * @value: the value to set
2698 * @size: the size of the value
2699 *
2700 * Sets the Smack value of the task. Only setting self
2701 * is permitted and only with privilege
2702 *
2703 * Returns the length of the smack label or an error code
2704 */
2705 static int smack_setprocattr(struct task_struct *p, char *name,
2706 void *value, size_t size)
2707 {
2708 int rc;
2709 struct task_smack *tsp;
2710 struct task_smack *oldtsp;
2711 struct cred *new;
2712 char *newsmack;
2713
2714 /*
2715 * Changing another process' Smack value is too dangerous
2716 * and supports no sane use case.
2717 */
2718 if (p != current)
2719 return -EPERM;
2720
2721 if (!smack_privileged(CAP_MAC_ADMIN))
2722 return -EPERM;
2723
2724 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
2725 return -EINVAL;
2726
2727 if (strcmp(name, "current") != 0)
2728 return -EINVAL;
2729
2730 newsmack = smk_import(value, size);
2731 if (newsmack == NULL)
2732 return -EINVAL;
2733
2734 /*
2735 * No process is ever allowed the web ("@") label.
2736 */
2737 if (newsmack == smack_known_web.smk_known)
2738 return -EPERM;
2739
2740 oldtsp = p->cred->security;
2741 new = prepare_creds();
2742 if (new == NULL)
2743 return -ENOMEM;
2744
2745 tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2746 if (tsp == NULL) {
2747 kfree(new);
2748 return -ENOMEM;
2749 }
2750 rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2751 if (rc != 0)
2752 return rc;
2753
2754 new->security = tsp;
2755 commit_creds(new);
2756 return size;
2757 }
2758
2759 /**
2760 * smack_unix_stream_connect - Smack access on UDS
2761 * @sock: one sock
2762 * @other: the other sock
2763 * @newsk: unused
2764 *
2765 * Return 0 if a subject with the smack of sock could access
2766 * an object with the smack of other, otherwise an error code
2767 */
2768 static int smack_unix_stream_connect(struct sock *sock,
2769 struct sock *other, struct sock *newsk)
2770 {
2771 struct socket_smack *ssp = sock->sk_security;
2772 struct socket_smack *osp = other->sk_security;
2773 struct socket_smack *nsp = newsk->sk_security;
2774 struct smk_audit_info ad;
2775 int rc = 0;
2776
2777 #ifdef CONFIG_AUDIT
2778 struct lsm_network_audit net;
2779
2780 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2781 smk_ad_setfield_u_net_sk(&ad, other);
2782 #endif
2783
2784 if (!smack_privileged(CAP_MAC_OVERRIDE))
2785 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2786
2787 /*
2788 * Cross reference the peer labels for SO_PEERSEC.
2789 */
2790 if (rc == 0) {
2791 nsp->smk_packet = ssp->smk_out;
2792 ssp->smk_packet = osp->smk_out;
2793 }
2794
2795 return rc;
2796 }
2797
2798 /**
2799 * smack_unix_may_send - Smack access on UDS
2800 * @sock: one socket
2801 * @other: the other socket
2802 *
2803 * Return 0 if a subject with the smack of sock could access
2804 * an object with the smack of other, otherwise an error code
2805 */
2806 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2807 {
2808 struct socket_smack *ssp = sock->sk->sk_security;
2809 struct socket_smack *osp = other->sk->sk_security;
2810 struct smk_audit_info ad;
2811 int rc = 0;
2812
2813 #ifdef CONFIG_AUDIT
2814 struct lsm_network_audit net;
2815
2816 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2817 smk_ad_setfield_u_net_sk(&ad, other->sk);
2818 #endif
2819
2820 if (!smack_privileged(CAP_MAC_OVERRIDE))
2821 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2822
2823 return rc;
2824 }
2825
2826 /**
2827 * smack_socket_sendmsg - Smack check based on destination host
2828 * @sock: the socket
2829 * @msg: the message
2830 * @size: the size of the message
2831 *
2832 * Return 0 if the current subject can write to the destination
2833 * host. This is only a question if the destination is a single
2834 * label host.
2835 */
2836 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2837 int size)
2838 {
2839 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2840
2841 /*
2842 * Perfectly reasonable for this to be NULL
2843 */
2844 if (sip == NULL || sip->sin_family != AF_INET)
2845 return 0;
2846
2847 return smack_netlabel_send(sock->sk, sip);
2848 }
2849
2850 /**
2851 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2852 * @sap: netlabel secattr
2853 * @ssp: socket security information
2854 *
2855 * Returns a pointer to a Smack label found on the label list.
2856 */
2857 static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
2858 struct socket_smack *ssp)
2859 {
2860 struct smack_known *kp;
2861 char *sp;
2862 int found = 0;
2863
2864 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2865 /*
2866 * Looks like a CIPSO packet.
2867 * If there are flags but no level netlabel isn't
2868 * behaving the way we expect it to.
2869 *
2870 * Look it up in the label table
2871 * Without guidance regarding the smack value
2872 * for the packet fall back on the network
2873 * ambient value.
2874 */
2875 rcu_read_lock();
2876 list_for_each_entry(kp, &smack_known_list, list) {
2877 if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl)
2878 continue;
2879 if (memcmp(sap->attr.mls.cat,
2880 kp->smk_netlabel.attr.mls.cat,
2881 SMK_CIPSOLEN) != 0)
2882 continue;
2883 found = 1;
2884 break;
2885 }
2886 rcu_read_unlock();
2887
2888 if (found)
2889 return kp->smk_known;
2890
2891 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
2892 return smack_known_web.smk_known;
2893 return smack_known_star.smk_known;
2894 }
2895 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2896 /*
2897 * Looks like a fallback, which gives us a secid.
2898 */
2899 sp = smack_from_secid(sap->attr.secid);
2900 /*
2901 * This has got to be a bug because it is
2902 * impossible to specify a fallback without
2903 * specifying the label, which will ensure
2904 * it has a secid, and the only way to get a
2905 * secid is from a fallback.
2906 */
2907 BUG_ON(sp == NULL);
2908 return sp;
2909 }
2910 /*
2911 * Without guidance regarding the smack value
2912 * for the packet fall back on the network
2913 * ambient value.
2914 */
2915 return smack_net_ambient;
2916 }
2917
2918 /**
2919 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2920 * @sk: socket
2921 * @skb: packet
2922 *
2923 * Returns 0 if the packet should be delivered, an error code otherwise
2924 */
2925 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2926 {
2927 struct netlbl_lsm_secattr secattr;
2928 struct socket_smack *ssp = sk->sk_security;
2929 char *csp;
2930 int rc;
2931 struct smk_audit_info ad;
2932 #ifdef CONFIG_AUDIT
2933 struct lsm_network_audit net;
2934 #endif
2935 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2936 return 0;
2937
2938 /*
2939 * Translate what netlabel gave us.
2940 */
2941 netlbl_secattr_init(&secattr);
2942
2943 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2944 if (rc == 0)
2945 csp = smack_from_secattr(&secattr, ssp);
2946 else
2947 csp = smack_net_ambient;
2948
2949 netlbl_secattr_destroy(&secattr);
2950
2951 #ifdef CONFIG_AUDIT
2952 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2953 ad.a.u.net->family = sk->sk_family;
2954 ad.a.u.net->netif = skb->skb_iif;
2955 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2956 #endif
2957 /*
2958 * Receiving a packet requires that the other end
2959 * be able to write here. Read access is not required.
2960 * This is the simplist possible security model
2961 * for networking.
2962 */
2963 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2964 if (rc != 0)
2965 netlbl_skbuff_err(skb, rc, 0);
2966 return rc;
2967 }
2968
2969 /**
2970 * smack_socket_getpeersec_stream - pull in packet label
2971 * @sock: the socket
2972 * @optval: user's destination
2973 * @optlen: size thereof
2974 * @len: max thereof
2975 *
2976 * returns zero on success, an error code otherwise
2977 */
2978 static int smack_socket_getpeersec_stream(struct socket *sock,
2979 char __user *optval,
2980 int __user *optlen, unsigned len)
2981 {
2982 struct socket_smack *ssp;
2983 char *rcp = "";
2984 int slen = 1;
2985 int rc = 0;
2986
2987 ssp = sock->sk->sk_security;
2988 if (ssp->smk_packet != NULL) {
2989 rcp = ssp->smk_packet;
2990 slen = strlen(rcp) + 1;
2991 }
2992
2993 if (slen > len)
2994 rc = -ERANGE;
2995 else if (copy_to_user(optval, rcp, slen) != 0)
2996 rc = -EFAULT;
2997
2998 if (put_user(slen, optlen) != 0)
2999 rc = -EFAULT;
3000
3001 return rc;
3002 }
3003
3004
3005 /**
3006 * smack_socket_getpeersec_dgram - pull in packet label
3007 * @sock: the peer socket
3008 * @skb: packet data
3009 * @secid: pointer to where to put the secid of the packet
3010 *
3011 * Sets the netlabel socket state on sk from parent
3012 */
3013 static int smack_socket_getpeersec_dgram(struct socket *sock,
3014 struct sk_buff *skb, u32 *secid)
3015
3016 {
3017 struct netlbl_lsm_secattr secattr;
3018 struct socket_smack *ssp = NULL;
3019 char *sp;
3020 int family = PF_UNSPEC;
3021 u32 s = 0; /* 0 is the invalid secid */
3022 int rc;
3023
3024 if (skb != NULL) {
3025 if (skb->protocol == htons(ETH_P_IP))
3026 family = PF_INET;
3027 else if (skb->protocol == htons(ETH_P_IPV6))
3028 family = PF_INET6;
3029 }
3030 if (family == PF_UNSPEC && sock != NULL)
3031 family = sock->sk->sk_family;
3032
3033 if (family == PF_UNIX) {
3034 ssp = sock->sk->sk_security;
3035 s = smack_to_secid(ssp->smk_out);
3036 } else if (family == PF_INET || family == PF_INET6) {
3037 /*
3038 * Translate what netlabel gave us.
3039 */
3040 if (sock != NULL && sock->sk != NULL)
3041 ssp = sock->sk->sk_security;
3042 netlbl_secattr_init(&secattr);
3043 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3044 if (rc == 0) {
3045 sp = smack_from_secattr(&secattr, ssp);
3046 s = smack_to_secid(sp);
3047 }
3048 netlbl_secattr_destroy(&secattr);
3049 }
3050 *secid = s;
3051 if (s == 0)
3052 return -EINVAL;
3053 return 0;
3054 }
3055
3056 /**
3057 * smack_sock_graft - Initialize a newly created socket with an existing sock
3058 * @sk: child sock
3059 * @parent: parent socket
3060 *
3061 * Set the smk_{in,out} state of an existing sock based on the process that
3062 * is creating the new socket.
3063 */
3064 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3065 {
3066 struct socket_smack *ssp;
3067
3068 if (sk == NULL ||
3069 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3070 return;
3071
3072 ssp = sk->sk_security;
3073 ssp->smk_in = ssp->smk_out = smk_of_current();
3074 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3075 }
3076
3077 /**
3078 * smack_inet_conn_request - Smack access check on connect
3079 * @sk: socket involved
3080 * @skb: packet
3081 * @req: unused
3082 *
3083 * Returns 0 if a task with the packet label could write to
3084 * the socket, otherwise an error code
3085 */
3086 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3087 struct request_sock *req)
3088 {
3089 u16 family = sk->sk_family;
3090 struct smack_known *skp;
3091 struct socket_smack *ssp = sk->sk_security;
3092 struct netlbl_lsm_secattr secattr;
3093 struct sockaddr_in addr;
3094 struct iphdr *hdr;
3095 char *sp;
3096 char *hsp;
3097 int rc;
3098 struct smk_audit_info ad;
3099 #ifdef CONFIG_AUDIT
3100 struct lsm_network_audit net;
3101 #endif
3102
3103 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3104 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3105 family = PF_INET;
3106
3107 netlbl_secattr_init(&secattr);
3108 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3109 if (rc == 0)
3110 sp = smack_from_secattr(&secattr, ssp);
3111 else
3112 sp = smack_known_huh.smk_known;
3113 netlbl_secattr_destroy(&secattr);
3114
3115 #ifdef CONFIG_AUDIT
3116 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3117 ad.a.u.net->family = family;
3118 ad.a.u.net->netif = skb->skb_iif;
3119 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3120 #endif
3121 /*
3122 * Receiving a packet requires that the other end be able to write
3123 * here. Read access is not required.
3124 */
3125 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
3126 if (rc != 0)
3127 return rc;
3128
3129 /*
3130 * Save the peer's label in the request_sock so we can later setup
3131 * smk_packet in the child socket so that SO_PEERCRED can report it.
3132 */
3133 req->peer_secid = smack_to_secid(sp);
3134
3135 /*
3136 * We need to decide if we want to label the incoming connection here
3137 * if we do we only need to label the request_sock and the stack will
3138 * propagate the wire-label to the sock when it is created.
3139 */
3140 hdr = ip_hdr(skb);
3141 addr.sin_addr.s_addr = hdr->saddr;
3142 rcu_read_lock();
3143 hsp = smack_host_label(&addr);
3144 rcu_read_unlock();
3145
3146 if (hsp == NULL) {
3147 skp = smk_find_entry(sp);
3148 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3149 } else
3150 netlbl_req_delattr(req);
3151
3152 return rc;
3153 }
3154
3155 /**
3156 * smack_inet_csk_clone - Copy the connection information to the new socket
3157 * @sk: the new socket
3158 * @req: the connection's request_sock
3159 *
3160 * Transfer the connection's peer label to the newly created socket.
3161 */
3162 static void smack_inet_csk_clone(struct sock *sk,
3163 const struct request_sock *req)
3164 {
3165 struct socket_smack *ssp = sk->sk_security;
3166
3167 if (req->peer_secid != 0)
3168 ssp->smk_packet = smack_from_secid(req->peer_secid);
3169 else
3170 ssp->smk_packet = NULL;
3171 }
3172
3173 /*
3174 * Key management security hooks
3175 *
3176 * Casey has not tested key support very heavily.
3177 * The permission check is most likely too restrictive.
3178 * If you care about keys please have a look.
3179 */
3180 #ifdef CONFIG_KEYS
3181
3182 /**
3183 * smack_key_alloc - Set the key security blob
3184 * @key: object
3185 * @cred: the credentials to use
3186 * @flags: unused
3187 *
3188 * No allocation required
3189 *
3190 * Returns 0
3191 */
3192 static int smack_key_alloc(struct key *key, const struct cred *cred,
3193 unsigned long flags)
3194 {
3195 key->security = smk_of_task(cred->security);
3196 return 0;
3197 }
3198
3199 /**
3200 * smack_key_free - Clear the key security blob
3201 * @key: the object
3202 *
3203 * Clear the blob pointer
3204 */
3205 static void smack_key_free(struct key *key)
3206 {
3207 key->security = NULL;
3208 }
3209
3210 /*
3211 * smack_key_permission - Smack access on a key
3212 * @key_ref: gets to the object
3213 * @cred: the credentials to use
3214 * @perm: unused
3215 *
3216 * Return 0 if the task has read and write to the object,
3217 * an error code otherwise
3218 */
3219 static int smack_key_permission(key_ref_t key_ref,
3220 const struct cred *cred, key_perm_t perm)
3221 {
3222 struct key *keyp;
3223 struct smk_audit_info ad;
3224 char *tsp = smk_of_task(cred->security);
3225
3226 keyp = key_ref_to_ptr(key_ref);
3227 if (keyp == NULL)
3228 return -EINVAL;
3229 /*
3230 * If the key hasn't been initialized give it access so that
3231 * it may do so.
3232 */
3233 if (keyp->security == NULL)
3234 return 0;
3235 /*
3236 * This should not occur
3237 */
3238 if (tsp == NULL)
3239 return -EACCES;
3240 #ifdef CONFIG_AUDIT
3241 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3242 ad.a.u.key_struct.key = keyp->serial;
3243 ad.a.u.key_struct.key_desc = keyp->description;
3244 #endif
3245 return smk_access(tsp, keyp->security,
3246 MAY_READWRITE, &ad);
3247 }
3248 #endif /* CONFIG_KEYS */
3249
3250 /*
3251 * Smack Audit hooks
3252 *
3253 * Audit requires a unique representation of each Smack specific
3254 * rule. This unique representation is used to distinguish the
3255 * object to be audited from remaining kernel objects and also
3256 * works as a glue between the audit hooks.
3257 *
3258 * Since repository entries are added but never deleted, we'll use
3259 * the smack_known label address related to the given audit rule as
3260 * the needed unique representation. This also better fits the smack
3261 * model where nearly everything is a label.
3262 */
3263 #ifdef CONFIG_AUDIT
3264
3265 /**
3266 * smack_audit_rule_init - Initialize a smack audit rule
3267 * @field: audit rule fields given from user-space (audit.h)
3268 * @op: required testing operator (=, !=, >, <, ...)
3269 * @rulestr: smack label to be audited
3270 * @vrule: pointer to save our own audit rule representation
3271 *
3272 * Prepare to audit cases where (@field @op @rulestr) is true.
3273 * The label to be audited is created if necessay.
3274 */
3275 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3276 {
3277 char **rule = (char **)vrule;
3278 *rule = NULL;
3279
3280 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3281 return -EINVAL;
3282
3283 if (op != Audit_equal && op != Audit_not_equal)
3284 return -EINVAL;
3285
3286 *rule = smk_import(rulestr, 0);
3287
3288 return 0;
3289 }
3290
3291 /**
3292 * smack_audit_rule_known - Distinguish Smack audit rules
3293 * @krule: rule of interest, in Audit kernel representation format
3294 *
3295 * This is used to filter Smack rules from remaining Audit ones.
3296 * If it's proved that this rule belongs to us, the
3297 * audit_rule_match hook will be called to do the final judgement.
3298 */
3299 static int smack_audit_rule_known(struct audit_krule *krule)
3300 {
3301 struct audit_field *f;
3302 int i;
3303
3304 for (i = 0; i < krule->field_count; i++) {
3305 f = &krule->fields[i];
3306
3307 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3308 return 1;
3309 }
3310
3311 return 0;
3312 }
3313
3314 /**
3315 * smack_audit_rule_match - Audit given object ?
3316 * @secid: security id for identifying the object to test
3317 * @field: audit rule flags given from user-space
3318 * @op: required testing operator
3319 * @vrule: smack internal rule presentation
3320 * @actx: audit context associated with the check
3321 *
3322 * The core Audit hook. It's used to take the decision of
3323 * whether to audit or not to audit a given object.
3324 */
3325 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3326 struct audit_context *actx)
3327 {
3328 char *smack;
3329 char *rule = vrule;
3330
3331 if (!rule) {
3332 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3333 "Smack: missing rule\n");
3334 return -ENOENT;
3335 }
3336
3337 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3338 return 0;
3339
3340 smack = smack_from_secid(secid);
3341
3342 /*
3343 * No need to do string comparisons. If a match occurs,
3344 * both pointers will point to the same smack_known
3345 * label.
3346 */
3347 if (op == Audit_equal)
3348 return (rule == smack);
3349 if (op == Audit_not_equal)
3350 return (rule != smack);
3351
3352 return 0;
3353 }
3354
3355 /**
3356 * smack_audit_rule_free - free smack rule representation
3357 * @vrule: rule to be freed.
3358 *
3359 * No memory was allocated.
3360 */
3361 static void smack_audit_rule_free(void *vrule)
3362 {
3363 /* No-op */
3364 }
3365
3366 #endif /* CONFIG_AUDIT */
3367
3368 /**
3369 * smack_secid_to_secctx - return the smack label for a secid
3370 * @secid: incoming integer
3371 * @secdata: destination
3372 * @seclen: how long it is
3373 *
3374 * Exists for networking code.
3375 */
3376 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3377 {
3378 char *sp = smack_from_secid(secid);
3379
3380 if (secdata)
3381 *secdata = sp;
3382 *seclen = strlen(sp);
3383 return 0;
3384 }
3385
3386 /**
3387 * smack_secctx_to_secid - return the secid for a smack label
3388 * @secdata: smack label
3389 * @seclen: how long result is
3390 * @secid: outgoing integer
3391 *
3392 * Exists for audit and networking code.
3393 */
3394 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3395 {
3396 *secid = smack_to_secid(secdata);
3397 return 0;
3398 }
3399
3400 /**
3401 * smack_release_secctx - don't do anything.
3402 * @secdata: unused
3403 * @seclen: unused
3404 *
3405 * Exists to make sure nothing gets done, and properly
3406 */
3407 static void smack_release_secctx(char *secdata, u32 seclen)
3408 {
3409 }
3410
3411 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3412 {
3413 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3414 }
3415
3416 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3417 {
3418 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3419 }
3420
3421 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3422 {
3423 int len = 0;
3424 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3425
3426 if (len < 0)
3427 return len;
3428 *ctxlen = len;
3429 return 0;
3430 }
3431
3432 struct security_operations smack_ops = {
3433 .name = "smack",
3434
3435 .ptrace_access_check = smack_ptrace_access_check,
3436 .ptrace_traceme = smack_ptrace_traceme,
3437 .syslog = smack_syslog,
3438
3439 .sb_alloc_security = smack_sb_alloc_security,
3440 .sb_free_security = smack_sb_free_security,
3441 .sb_copy_data = smack_sb_copy_data,
3442 .sb_kern_mount = smack_sb_kern_mount,
3443 .sb_statfs = smack_sb_statfs,
3444 .sb_mount = smack_sb_mount,
3445 .sb_umount = smack_sb_umount,
3446
3447 .bprm_set_creds = smack_bprm_set_creds,
3448 .bprm_committing_creds = smack_bprm_committing_creds,
3449 .bprm_secureexec = smack_bprm_secureexec,
3450
3451 .inode_alloc_security = smack_inode_alloc_security,
3452 .inode_free_security = smack_inode_free_security,
3453 .inode_init_security = smack_inode_init_security,
3454 .inode_link = smack_inode_link,
3455 .inode_unlink = smack_inode_unlink,
3456 .inode_rmdir = smack_inode_rmdir,
3457 .inode_rename = smack_inode_rename,
3458 .inode_permission = smack_inode_permission,
3459 .inode_setattr = smack_inode_setattr,
3460 .inode_getattr = smack_inode_getattr,
3461 .inode_setxattr = smack_inode_setxattr,
3462 .inode_post_setxattr = smack_inode_post_setxattr,
3463 .inode_getxattr = smack_inode_getxattr,
3464 .inode_removexattr = smack_inode_removexattr,
3465 .inode_getsecurity = smack_inode_getsecurity,
3466 .inode_setsecurity = smack_inode_setsecurity,
3467 .inode_listsecurity = smack_inode_listsecurity,
3468 .inode_getsecid = smack_inode_getsecid,
3469
3470 .file_permission = smack_file_permission,
3471 .file_alloc_security = smack_file_alloc_security,
3472 .file_free_security = smack_file_free_security,
3473 .file_ioctl = smack_file_ioctl,
3474 .file_lock = smack_file_lock,
3475 .file_fcntl = smack_file_fcntl,
3476 .mmap_file = smack_mmap_file,
3477 .mmap_addr = cap_mmap_addr,
3478 .file_set_fowner = smack_file_set_fowner,
3479 .file_send_sigiotask = smack_file_send_sigiotask,
3480 .file_receive = smack_file_receive,
3481
3482 .file_open = smack_file_open,
3483
3484 .cred_alloc_blank = smack_cred_alloc_blank,
3485 .cred_free = smack_cred_free,
3486 .cred_prepare = smack_cred_prepare,
3487 .cred_transfer = smack_cred_transfer,
3488 .kernel_act_as = smack_kernel_act_as,
3489 .kernel_create_files_as = smack_kernel_create_files_as,
3490 .task_setpgid = smack_task_setpgid,
3491 .task_getpgid = smack_task_getpgid,
3492 .task_getsid = smack_task_getsid,
3493 .task_getsecid = smack_task_getsecid,
3494 .task_setnice = smack_task_setnice,
3495 .task_setioprio = smack_task_setioprio,
3496 .task_getioprio = smack_task_getioprio,
3497 .task_setscheduler = smack_task_setscheduler,
3498 .task_getscheduler = smack_task_getscheduler,
3499 .task_movememory = smack_task_movememory,
3500 .task_kill = smack_task_kill,
3501 .task_wait = smack_task_wait,
3502 .task_to_inode = smack_task_to_inode,
3503
3504 .ipc_permission = smack_ipc_permission,
3505 .ipc_getsecid = smack_ipc_getsecid,
3506
3507 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3508 .msg_msg_free_security = smack_msg_msg_free_security,
3509
3510 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3511 .msg_queue_free_security = smack_msg_queue_free_security,
3512 .msg_queue_associate = smack_msg_queue_associate,
3513 .msg_queue_msgctl = smack_msg_queue_msgctl,
3514 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3515 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3516
3517 .shm_alloc_security = smack_shm_alloc_security,
3518 .shm_free_security = smack_shm_free_security,
3519 .shm_associate = smack_shm_associate,
3520 .shm_shmctl = smack_shm_shmctl,
3521 .shm_shmat = smack_shm_shmat,
3522
3523 .sem_alloc_security = smack_sem_alloc_security,
3524 .sem_free_security = smack_sem_free_security,
3525 .sem_associate = smack_sem_associate,
3526 .sem_semctl = smack_sem_semctl,
3527 .sem_semop = smack_sem_semop,
3528
3529 .d_instantiate = smack_d_instantiate,
3530
3531 .getprocattr = smack_getprocattr,
3532 .setprocattr = smack_setprocattr,
3533
3534 .unix_stream_connect = smack_unix_stream_connect,
3535 .unix_may_send = smack_unix_may_send,
3536
3537 .socket_post_create = smack_socket_post_create,
3538 .socket_connect = smack_socket_connect,
3539 .socket_sendmsg = smack_socket_sendmsg,
3540 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3541 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3542 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3543 .sk_alloc_security = smack_sk_alloc_security,
3544 .sk_free_security = smack_sk_free_security,
3545 .sock_graft = smack_sock_graft,
3546 .inet_conn_request = smack_inet_conn_request,
3547 .inet_csk_clone = smack_inet_csk_clone,
3548
3549 /* key management security hooks */
3550 #ifdef CONFIG_KEYS
3551 .key_alloc = smack_key_alloc,
3552 .key_free = smack_key_free,
3553 .key_permission = smack_key_permission,
3554 #endif /* CONFIG_KEYS */
3555
3556 /* Audit hooks */
3557 #ifdef CONFIG_AUDIT
3558 .audit_rule_init = smack_audit_rule_init,
3559 .audit_rule_known = smack_audit_rule_known,
3560 .audit_rule_match = smack_audit_rule_match,
3561 .audit_rule_free = smack_audit_rule_free,
3562 #endif /* CONFIG_AUDIT */
3563
3564 .secid_to_secctx = smack_secid_to_secctx,
3565 .secctx_to_secid = smack_secctx_to_secid,
3566 .release_secctx = smack_release_secctx,
3567 .inode_notifysecctx = smack_inode_notifysecctx,
3568 .inode_setsecctx = smack_inode_setsecctx,
3569 .inode_getsecctx = smack_inode_getsecctx,
3570 };
3571
3572
3573 static __init void init_smack_known_list(void)
3574 {
3575 /*
3576 * Initialize rule list locks
3577 */
3578 mutex_init(&smack_known_huh.smk_rules_lock);
3579 mutex_init(&smack_known_hat.smk_rules_lock);
3580 mutex_init(&smack_known_floor.smk_rules_lock);
3581 mutex_init(&smack_known_star.smk_rules_lock);
3582 mutex_init(&smack_known_invalid.smk_rules_lock);
3583 mutex_init(&smack_known_web.smk_rules_lock);
3584 /*
3585 * Initialize rule lists
3586 */
3587 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
3588 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
3589 INIT_LIST_HEAD(&smack_known_star.smk_rules);
3590 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
3591 INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
3592 INIT_LIST_HEAD(&smack_known_web.smk_rules);
3593 /*
3594 * Create the known labels list
3595 */
3596 list_add(&smack_known_huh.list, &smack_known_list);
3597 list_add(&smack_known_hat.list, &smack_known_list);
3598 list_add(&smack_known_star.list, &smack_known_list);
3599 list_add(&smack_known_floor.list, &smack_known_list);
3600 list_add(&smack_known_invalid.list, &smack_known_list);
3601 list_add(&smack_known_web.list, &smack_known_list);
3602 }
3603
3604 /**
3605 * smack_init - initialize the smack system
3606 *
3607 * Returns 0
3608 */
3609 static __init int smack_init(void)
3610 {
3611 struct cred *cred;
3612 struct task_smack *tsp;
3613
3614 if (!security_module_enable(&smack_ops))
3615 return 0;
3616
3617 tsp = new_task_smack(smack_known_floor.smk_known,
3618 smack_known_floor.smk_known, GFP_KERNEL);
3619 if (tsp == NULL)
3620 return -ENOMEM;
3621
3622 printk(KERN_INFO "Smack: Initializing.\n");
3623
3624 /*
3625 * Set the security state for the initial task.
3626 */
3627 cred = (struct cred *) current->cred;
3628 cred->security = tsp;
3629
3630 /* initialize the smack_known_list */
3631 init_smack_known_list();
3632
3633 /*
3634 * Register with LSM
3635 */
3636 if (register_security(&smack_ops))
3637 panic("smack: Unable to register with kernel.\n");
3638
3639 return 0;
3640 }
3641
3642 /*
3643 * Smack requires early initialization in order to label
3644 * all processes and objects when they are created.
3645 */
3646 security_initcall(smack_init);
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