Merge tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rosted...
[GitHub/mt8127/android_kernel_alcatel_ttab.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(const char *dev_name, struct path *path,
412 const 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 = file_inode(bprm->file);
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_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
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_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
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 int may;
1191 int mmay;
1192 int tmay;
1193 int rc;
1194
1195 if (file == NULL)
1196 return 0;
1197
1198 isp = file_inode(file)->i_security;
1199 if (isp->smk_mmap == NULL)
1200 return 0;
1201 msmack = isp->smk_mmap;
1202
1203 tsp = current_security();
1204 sp = smk_of_current();
1205 skp = smk_find_entry(sp);
1206 rc = 0;
1207
1208 rcu_read_lock();
1209 /*
1210 * For each Smack rule associated with the subject
1211 * label verify that the SMACK64MMAP also has access
1212 * to that rule's object label.
1213 */
1214 list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1215 osmack = srp->smk_object;
1216 /*
1217 * Matching labels always allows access.
1218 */
1219 if (msmack == osmack)
1220 continue;
1221 /*
1222 * If there is a matching local rule take
1223 * that into account as well.
1224 */
1225 may = smk_access_entry(srp->smk_subject, osmack,
1226 &tsp->smk_rules);
1227 if (may == -ENOENT)
1228 may = srp->smk_access;
1229 else
1230 may &= srp->smk_access;
1231 /*
1232 * If may is zero the SMACK64MMAP subject can't
1233 * possibly have less access.
1234 */
1235 if (may == 0)
1236 continue;
1237
1238 /*
1239 * Fetch the global list entry.
1240 * If there isn't one a SMACK64MMAP subject
1241 * can't have as much access as current.
1242 */
1243 skp = smk_find_entry(msmack);
1244 mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
1245 if (mmay == -ENOENT) {
1246 rc = -EACCES;
1247 break;
1248 }
1249 /*
1250 * If there is a local entry it modifies the
1251 * potential access, too.
1252 */
1253 tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1254 if (tmay != -ENOENT)
1255 mmay &= tmay;
1256
1257 /*
1258 * If there is any access available to current that is
1259 * not available to a SMACK64MMAP subject
1260 * deny access.
1261 */
1262 if ((may | mmay) != mmay) {
1263 rc = -EACCES;
1264 break;
1265 }
1266 }
1267
1268 rcu_read_unlock();
1269
1270 return rc;
1271 }
1272
1273 /**
1274 * smack_file_set_fowner - set the file security blob value
1275 * @file: object in question
1276 *
1277 * Returns 0
1278 * Further research may be required on this one.
1279 */
1280 static int smack_file_set_fowner(struct file *file)
1281 {
1282 file->f_security = smk_of_current();
1283 return 0;
1284 }
1285
1286 /**
1287 * smack_file_send_sigiotask - Smack on sigio
1288 * @tsk: The target task
1289 * @fown: the object the signal come from
1290 * @signum: unused
1291 *
1292 * Allow a privileged task to get signals even if it shouldn't
1293 *
1294 * Returns 0 if a subject with the object's smack could
1295 * write to the task, an error code otherwise.
1296 */
1297 static int smack_file_send_sigiotask(struct task_struct *tsk,
1298 struct fown_struct *fown, int signum)
1299 {
1300 struct file *file;
1301 int rc;
1302 char *tsp = smk_of_task(tsk->cred->security);
1303 struct smk_audit_info ad;
1304
1305 /*
1306 * struct fown_struct is never outside the context of a struct file
1307 */
1308 file = container_of(fown, struct file, f_owner);
1309
1310 /* we don't log here as rc can be overriden */
1311 rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1312 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1313 rc = 0;
1314
1315 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1316 smk_ad_setfield_u_tsk(&ad, tsk);
1317 smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1318 return rc;
1319 }
1320
1321 /**
1322 * smack_file_receive - Smack file receive check
1323 * @file: the object
1324 *
1325 * Returns 0 if current has access, error code otherwise
1326 */
1327 static int smack_file_receive(struct file *file)
1328 {
1329 int may = 0;
1330 struct smk_audit_info ad;
1331
1332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1333 smk_ad_setfield_u_fs_path(&ad, file->f_path);
1334 /*
1335 * This code relies on bitmasks.
1336 */
1337 if (file->f_mode & FMODE_READ)
1338 may = MAY_READ;
1339 if (file->f_mode & FMODE_WRITE)
1340 may |= MAY_WRITE;
1341
1342 return smk_curacc(file->f_security, may, &ad);
1343 }
1344
1345 /**
1346 * smack_file_open - Smack dentry open processing
1347 * @file: the object
1348 * @cred: unused
1349 *
1350 * Set the security blob in the file structure.
1351 *
1352 * Returns 0
1353 */
1354 static int smack_file_open(struct file *file, const struct cred *cred)
1355 {
1356 struct inode_smack *isp = file_inode(file)->i_security;
1357
1358 file->f_security = isp->smk_inode;
1359
1360 return 0;
1361 }
1362
1363 /*
1364 * Task hooks
1365 */
1366
1367 /**
1368 * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1369 * @new: the new credentials
1370 * @gfp: the atomicity of any memory allocations
1371 *
1372 * Prepare a blank set of credentials for modification. This must allocate all
1373 * the memory the LSM module might require such that cred_transfer() can
1374 * complete without error.
1375 */
1376 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1377 {
1378 struct task_smack *tsp;
1379
1380 tsp = new_task_smack(NULL, NULL, gfp);
1381 if (tsp == NULL)
1382 return -ENOMEM;
1383
1384 cred->security = tsp;
1385
1386 return 0;
1387 }
1388
1389
1390 /**
1391 * smack_cred_free - "free" task-level security credentials
1392 * @cred: the credentials in question
1393 *
1394 */
1395 static void smack_cred_free(struct cred *cred)
1396 {
1397 struct task_smack *tsp = cred->security;
1398 struct smack_rule *rp;
1399 struct list_head *l;
1400 struct list_head *n;
1401
1402 if (tsp == NULL)
1403 return;
1404 cred->security = NULL;
1405
1406 list_for_each_safe(l, n, &tsp->smk_rules) {
1407 rp = list_entry(l, struct smack_rule, list);
1408 list_del(&rp->list);
1409 kfree(rp);
1410 }
1411 kfree(tsp);
1412 }
1413
1414 /**
1415 * smack_cred_prepare - prepare new set of credentials for modification
1416 * @new: the new credentials
1417 * @old: the original credentials
1418 * @gfp: the atomicity of any memory allocations
1419 *
1420 * Prepare a new set of credentials for modification.
1421 */
1422 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1423 gfp_t gfp)
1424 {
1425 struct task_smack *old_tsp = old->security;
1426 struct task_smack *new_tsp;
1427 int rc;
1428
1429 new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1430 if (new_tsp == NULL)
1431 return -ENOMEM;
1432
1433 rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1434 if (rc != 0)
1435 return rc;
1436
1437 new->security = new_tsp;
1438 return 0;
1439 }
1440
1441 /**
1442 * smack_cred_transfer - Transfer the old credentials to the new credentials
1443 * @new: the new credentials
1444 * @old: the original credentials
1445 *
1446 * Fill in a set of blank credentials from another set of credentials.
1447 */
1448 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1449 {
1450 struct task_smack *old_tsp = old->security;
1451 struct task_smack *new_tsp = new->security;
1452
1453 new_tsp->smk_task = old_tsp->smk_task;
1454 new_tsp->smk_forked = old_tsp->smk_task;
1455 mutex_init(&new_tsp->smk_rules_lock);
1456 INIT_LIST_HEAD(&new_tsp->smk_rules);
1457
1458
1459 /* cbs copy rule list */
1460 }
1461
1462 /**
1463 * smack_kernel_act_as - Set the subjective context in a set of credentials
1464 * @new: points to the set of credentials to be modified.
1465 * @secid: specifies the security ID to be set
1466 *
1467 * Set the security data for a kernel service.
1468 */
1469 static int smack_kernel_act_as(struct cred *new, u32 secid)
1470 {
1471 struct task_smack *new_tsp = new->security;
1472 char *smack = smack_from_secid(secid);
1473
1474 if (smack == NULL)
1475 return -EINVAL;
1476
1477 new_tsp->smk_task = smack;
1478 return 0;
1479 }
1480
1481 /**
1482 * smack_kernel_create_files_as - Set the file creation label in a set of creds
1483 * @new: points to the set of credentials to be modified
1484 * @inode: points to the inode to use as a reference
1485 *
1486 * Set the file creation context in a set of credentials to the same
1487 * as the objective context of the specified inode
1488 */
1489 static int smack_kernel_create_files_as(struct cred *new,
1490 struct inode *inode)
1491 {
1492 struct inode_smack *isp = inode->i_security;
1493 struct task_smack *tsp = new->security;
1494
1495 tsp->smk_forked = isp->smk_inode;
1496 tsp->smk_task = isp->smk_inode;
1497 return 0;
1498 }
1499
1500 /**
1501 * smk_curacc_on_task - helper to log task related access
1502 * @p: the task object
1503 * @access: the access requested
1504 * @caller: name of the calling function for audit
1505 *
1506 * Return 0 if access is permitted
1507 */
1508 static int smk_curacc_on_task(struct task_struct *p, int access,
1509 const char *caller)
1510 {
1511 struct smk_audit_info ad;
1512
1513 smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1514 smk_ad_setfield_u_tsk(&ad, p);
1515 return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1516 }
1517
1518 /**
1519 * smack_task_setpgid - Smack check on setting pgid
1520 * @p: the task object
1521 * @pgid: unused
1522 *
1523 * Return 0 if write access is permitted
1524 */
1525 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1526 {
1527 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1528 }
1529
1530 /**
1531 * smack_task_getpgid - Smack access check for getpgid
1532 * @p: the object task
1533 *
1534 * Returns 0 if current can read the object task, error code otherwise
1535 */
1536 static int smack_task_getpgid(struct task_struct *p)
1537 {
1538 return smk_curacc_on_task(p, MAY_READ, __func__);
1539 }
1540
1541 /**
1542 * smack_task_getsid - Smack access check for getsid
1543 * @p: the object task
1544 *
1545 * Returns 0 if current can read the object task, error code otherwise
1546 */
1547 static int smack_task_getsid(struct task_struct *p)
1548 {
1549 return smk_curacc_on_task(p, MAY_READ, __func__);
1550 }
1551
1552 /**
1553 * smack_task_getsecid - get the secid of the task
1554 * @p: the object task
1555 * @secid: where to put the result
1556 *
1557 * Sets the secid to contain a u32 version of the smack label.
1558 */
1559 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1560 {
1561 *secid = smack_to_secid(smk_of_task(task_security(p)));
1562 }
1563
1564 /**
1565 * smack_task_setnice - Smack check on setting nice
1566 * @p: the task object
1567 * @nice: unused
1568 *
1569 * Return 0 if write access is permitted
1570 */
1571 static int smack_task_setnice(struct task_struct *p, int nice)
1572 {
1573 int rc;
1574
1575 rc = cap_task_setnice(p, nice);
1576 if (rc == 0)
1577 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1578 return rc;
1579 }
1580
1581 /**
1582 * smack_task_setioprio - Smack check on setting ioprio
1583 * @p: the task object
1584 * @ioprio: unused
1585 *
1586 * Return 0 if write access is permitted
1587 */
1588 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1589 {
1590 int rc;
1591
1592 rc = cap_task_setioprio(p, ioprio);
1593 if (rc == 0)
1594 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1595 return rc;
1596 }
1597
1598 /**
1599 * smack_task_getioprio - Smack check on reading ioprio
1600 * @p: the task object
1601 *
1602 * Return 0 if read access is permitted
1603 */
1604 static int smack_task_getioprio(struct task_struct *p)
1605 {
1606 return smk_curacc_on_task(p, MAY_READ, __func__);
1607 }
1608
1609 /**
1610 * smack_task_setscheduler - Smack check on setting scheduler
1611 * @p: the task object
1612 * @policy: unused
1613 * @lp: unused
1614 *
1615 * Return 0 if read access is permitted
1616 */
1617 static int smack_task_setscheduler(struct task_struct *p)
1618 {
1619 int rc;
1620
1621 rc = cap_task_setscheduler(p);
1622 if (rc == 0)
1623 rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1624 return rc;
1625 }
1626
1627 /**
1628 * smack_task_getscheduler - Smack check on reading scheduler
1629 * @p: the task object
1630 *
1631 * Return 0 if read access is permitted
1632 */
1633 static int smack_task_getscheduler(struct task_struct *p)
1634 {
1635 return smk_curacc_on_task(p, MAY_READ, __func__);
1636 }
1637
1638 /**
1639 * smack_task_movememory - Smack check on moving memory
1640 * @p: the task object
1641 *
1642 * Return 0 if write access is permitted
1643 */
1644 static int smack_task_movememory(struct task_struct *p)
1645 {
1646 return smk_curacc_on_task(p, MAY_WRITE, __func__);
1647 }
1648
1649 /**
1650 * smack_task_kill - Smack check on signal delivery
1651 * @p: the task object
1652 * @info: unused
1653 * @sig: unused
1654 * @secid: identifies the smack to use in lieu of current's
1655 *
1656 * Return 0 if write access is permitted
1657 *
1658 * The secid behavior is an artifact of an SELinux hack
1659 * in the USB code. Someday it may go away.
1660 */
1661 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1662 int sig, u32 secid)
1663 {
1664 struct smk_audit_info ad;
1665
1666 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1667 smk_ad_setfield_u_tsk(&ad, p);
1668 /*
1669 * Sending a signal requires that the sender
1670 * can write the receiver.
1671 */
1672 if (secid == 0)
1673 return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1674 &ad);
1675 /*
1676 * If the secid isn't 0 we're dealing with some USB IO
1677 * specific behavior. This is not clean. For one thing
1678 * we can't take privilege into account.
1679 */
1680 return smk_access(smack_from_secid(secid),
1681 smk_of_task(task_security(p)), MAY_WRITE, &ad);
1682 }
1683
1684 /**
1685 * smack_task_wait - Smack access check for waiting
1686 * @p: task to wait for
1687 *
1688 * Returns 0
1689 */
1690 static int smack_task_wait(struct task_struct *p)
1691 {
1692 /*
1693 * Allow the operation to succeed.
1694 * Zombies are bad.
1695 * In userless environments (e.g. phones) programs
1696 * get marked with SMACK64EXEC and even if the parent
1697 * and child shouldn't be talking the parent still
1698 * may expect to know when the child exits.
1699 */
1700 return 0;
1701 }
1702
1703 /**
1704 * smack_task_to_inode - copy task smack into the inode blob
1705 * @p: task to copy from
1706 * @inode: inode to copy to
1707 *
1708 * Sets the smack pointer in the inode security blob
1709 */
1710 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1711 {
1712 struct inode_smack *isp = inode->i_security;
1713 isp->smk_inode = smk_of_task(task_security(p));
1714 }
1715
1716 /*
1717 * Socket hooks.
1718 */
1719
1720 /**
1721 * smack_sk_alloc_security - Allocate a socket blob
1722 * @sk: the socket
1723 * @family: unused
1724 * @gfp_flags: memory allocation flags
1725 *
1726 * Assign Smack pointers to current
1727 *
1728 * Returns 0 on success, -ENOMEM is there's no memory
1729 */
1730 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1731 {
1732 char *csp = smk_of_current();
1733 struct socket_smack *ssp;
1734
1735 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1736 if (ssp == NULL)
1737 return -ENOMEM;
1738
1739 ssp->smk_in = csp;
1740 ssp->smk_out = csp;
1741 ssp->smk_packet = NULL;
1742
1743 sk->sk_security = ssp;
1744
1745 return 0;
1746 }
1747
1748 /**
1749 * smack_sk_free_security - Free a socket blob
1750 * @sk: the socket
1751 *
1752 * Clears the blob pointer
1753 */
1754 static void smack_sk_free_security(struct sock *sk)
1755 {
1756 kfree(sk->sk_security);
1757 }
1758
1759 /**
1760 * smack_host_label - check host based restrictions
1761 * @sip: the object end
1762 *
1763 * looks for host based access restrictions
1764 *
1765 * This version will only be appropriate for really small sets of single label
1766 * hosts. The caller is responsible for ensuring that the RCU read lock is
1767 * taken before calling this function.
1768 *
1769 * Returns the label of the far end or NULL if it's not special.
1770 */
1771 static char *smack_host_label(struct sockaddr_in *sip)
1772 {
1773 struct smk_netlbladdr *snp;
1774 struct in_addr *siap = &sip->sin_addr;
1775
1776 if (siap->s_addr == 0)
1777 return NULL;
1778
1779 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1780 /*
1781 * we break after finding the first match because
1782 * the list is sorted from longest to shortest mask
1783 * so we have found the most specific match
1784 */
1785 if ((&snp->smk_host.sin_addr)->s_addr ==
1786 (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1787 /* we have found the special CIPSO option */
1788 if (snp->smk_label == smack_cipso_option)
1789 return NULL;
1790 return snp->smk_label;
1791 }
1792
1793 return NULL;
1794 }
1795
1796 /**
1797 * smack_netlabel - Set the secattr on a socket
1798 * @sk: the socket
1799 * @labeled: socket label scheme
1800 *
1801 * Convert the outbound smack value (smk_out) to a
1802 * secattr and attach it to the socket.
1803 *
1804 * Returns 0 on success or an error code
1805 */
1806 static int smack_netlabel(struct sock *sk, int labeled)
1807 {
1808 struct smack_known *skp;
1809 struct socket_smack *ssp = sk->sk_security;
1810 int rc = 0;
1811
1812 /*
1813 * Usually the netlabel code will handle changing the
1814 * packet labeling based on the label.
1815 * The case of a single label host is different, because
1816 * a single label host should never get a labeled packet
1817 * even though the label is usually associated with a packet
1818 * label.
1819 */
1820 local_bh_disable();
1821 bh_lock_sock_nested(sk);
1822
1823 if (ssp->smk_out == smack_net_ambient ||
1824 labeled == SMACK_UNLABELED_SOCKET)
1825 netlbl_sock_delattr(sk);
1826 else {
1827 skp = smk_find_entry(ssp->smk_out);
1828 rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
1829 }
1830
1831 bh_unlock_sock(sk);
1832 local_bh_enable();
1833
1834 return rc;
1835 }
1836
1837 /**
1838 * smack_netlbel_send - Set the secattr on a socket and perform access checks
1839 * @sk: the socket
1840 * @sap: the destination address
1841 *
1842 * Set the correct secattr for the given socket based on the destination
1843 * address and perform any outbound access checks needed.
1844 *
1845 * Returns 0 on success or an error code.
1846 *
1847 */
1848 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1849 {
1850 int rc;
1851 int sk_lbl;
1852 char *hostsp;
1853 struct socket_smack *ssp = sk->sk_security;
1854 struct smk_audit_info ad;
1855
1856 rcu_read_lock();
1857 hostsp = smack_host_label(sap);
1858 if (hostsp != NULL) {
1859 #ifdef CONFIG_AUDIT
1860 struct lsm_network_audit net;
1861
1862 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
1863 ad.a.u.net->family = sap->sin_family;
1864 ad.a.u.net->dport = sap->sin_port;
1865 ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
1866 #endif
1867 sk_lbl = SMACK_UNLABELED_SOCKET;
1868 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1869 } else {
1870 sk_lbl = SMACK_CIPSO_SOCKET;
1871 rc = 0;
1872 }
1873 rcu_read_unlock();
1874 if (rc != 0)
1875 return rc;
1876
1877 return smack_netlabel(sk, sk_lbl);
1878 }
1879
1880 /**
1881 * smack_inode_setsecurity - set smack xattrs
1882 * @inode: the object
1883 * @name: attribute name
1884 * @value: attribute value
1885 * @size: size of the attribute
1886 * @flags: unused
1887 *
1888 * Sets the named attribute in the appropriate blob
1889 *
1890 * Returns 0 on success, or an error code
1891 */
1892 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1893 const void *value, size_t size, int flags)
1894 {
1895 char *sp;
1896 struct inode_smack *nsp = inode->i_security;
1897 struct socket_smack *ssp;
1898 struct socket *sock;
1899 int rc = 0;
1900
1901 if (value == NULL || size > SMK_LONGLABEL || size == 0)
1902 return -EACCES;
1903
1904 sp = smk_import(value, size);
1905 if (sp == NULL)
1906 return -EINVAL;
1907
1908 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1909 nsp->smk_inode = sp;
1910 nsp->smk_flags |= SMK_INODE_INSTANT;
1911 return 0;
1912 }
1913 /*
1914 * The rest of the Smack xattrs are only on sockets.
1915 */
1916 if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1917 return -EOPNOTSUPP;
1918
1919 sock = SOCKET_I(inode);
1920 if (sock == NULL || sock->sk == NULL)
1921 return -EOPNOTSUPP;
1922
1923 ssp = sock->sk->sk_security;
1924
1925 if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1926 ssp->smk_in = sp;
1927 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1928 ssp->smk_out = sp;
1929 if (sock->sk->sk_family != PF_UNIX) {
1930 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1931 if (rc != 0)
1932 printk(KERN_WARNING
1933 "Smack: \"%s\" netlbl error %d.\n",
1934 __func__, -rc);
1935 }
1936 } else
1937 return -EOPNOTSUPP;
1938
1939 return 0;
1940 }
1941
1942 /**
1943 * smack_socket_post_create - finish socket setup
1944 * @sock: the socket
1945 * @family: protocol family
1946 * @type: unused
1947 * @protocol: unused
1948 * @kern: unused
1949 *
1950 * Sets the netlabel information on the socket
1951 *
1952 * Returns 0 on success, and error code otherwise
1953 */
1954 static int smack_socket_post_create(struct socket *sock, int family,
1955 int type, int protocol, int kern)
1956 {
1957 if (family != PF_INET || sock->sk == NULL)
1958 return 0;
1959 /*
1960 * Set the outbound netlbl.
1961 */
1962 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1963 }
1964
1965 /**
1966 * smack_socket_connect - connect access check
1967 * @sock: the socket
1968 * @sap: the other end
1969 * @addrlen: size of sap
1970 *
1971 * Verifies that a connection may be possible
1972 *
1973 * Returns 0 on success, and error code otherwise
1974 */
1975 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
1976 int addrlen)
1977 {
1978 if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
1979 return 0;
1980 if (addrlen < sizeof(struct sockaddr_in))
1981 return -EINVAL;
1982
1983 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
1984 }
1985
1986 /**
1987 * smack_flags_to_may - convert S_ to MAY_ values
1988 * @flags: the S_ value
1989 *
1990 * Returns the equivalent MAY_ value
1991 */
1992 static int smack_flags_to_may(int flags)
1993 {
1994 int may = 0;
1995
1996 if (flags & S_IRUGO)
1997 may |= MAY_READ;
1998 if (flags & S_IWUGO)
1999 may |= MAY_WRITE;
2000 if (flags & S_IXUGO)
2001 may |= MAY_EXEC;
2002
2003 return may;
2004 }
2005
2006 /**
2007 * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2008 * @msg: the object
2009 *
2010 * Returns 0
2011 */
2012 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2013 {
2014 msg->security = smk_of_current();
2015 return 0;
2016 }
2017
2018 /**
2019 * smack_msg_msg_free_security - Clear the security blob for msg_msg
2020 * @msg: the object
2021 *
2022 * Clears the blob pointer
2023 */
2024 static void smack_msg_msg_free_security(struct msg_msg *msg)
2025 {
2026 msg->security = NULL;
2027 }
2028
2029 /**
2030 * smack_of_shm - the smack pointer for the shm
2031 * @shp: the object
2032 *
2033 * Returns a pointer to the smack value
2034 */
2035 static char *smack_of_shm(struct shmid_kernel *shp)
2036 {
2037 return (char *)shp->shm_perm.security;
2038 }
2039
2040 /**
2041 * smack_shm_alloc_security - Set the security blob for shm
2042 * @shp: the object
2043 *
2044 * Returns 0
2045 */
2046 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2047 {
2048 struct kern_ipc_perm *isp = &shp->shm_perm;
2049
2050 isp->security = smk_of_current();
2051 return 0;
2052 }
2053
2054 /**
2055 * smack_shm_free_security - Clear the security blob for shm
2056 * @shp: the object
2057 *
2058 * Clears the blob pointer
2059 */
2060 static void smack_shm_free_security(struct shmid_kernel *shp)
2061 {
2062 struct kern_ipc_perm *isp = &shp->shm_perm;
2063
2064 isp->security = NULL;
2065 }
2066
2067 /**
2068 * smk_curacc_shm : check if current has access on shm
2069 * @shp : the object
2070 * @access : access requested
2071 *
2072 * Returns 0 if current has the requested access, error code otherwise
2073 */
2074 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2075 {
2076 char *ssp = smack_of_shm(shp);
2077 struct smk_audit_info ad;
2078
2079 #ifdef CONFIG_AUDIT
2080 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2081 ad.a.u.ipc_id = shp->shm_perm.id;
2082 #endif
2083 return smk_curacc(ssp, access, &ad);
2084 }
2085
2086 /**
2087 * smack_shm_associate - Smack access check for shm
2088 * @shp: the object
2089 * @shmflg: access requested
2090 *
2091 * Returns 0 if current has the requested access, error code otherwise
2092 */
2093 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2094 {
2095 int may;
2096
2097 may = smack_flags_to_may(shmflg);
2098 return smk_curacc_shm(shp, may);
2099 }
2100
2101 /**
2102 * smack_shm_shmctl - Smack access check for shm
2103 * @shp: the object
2104 * @cmd: what it wants to do
2105 *
2106 * Returns 0 if current has the requested access, error code otherwise
2107 */
2108 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2109 {
2110 int may;
2111
2112 switch (cmd) {
2113 case IPC_STAT:
2114 case SHM_STAT:
2115 may = MAY_READ;
2116 break;
2117 case IPC_SET:
2118 case SHM_LOCK:
2119 case SHM_UNLOCK:
2120 case IPC_RMID:
2121 may = MAY_READWRITE;
2122 break;
2123 case IPC_INFO:
2124 case SHM_INFO:
2125 /*
2126 * System level information.
2127 */
2128 return 0;
2129 default:
2130 return -EINVAL;
2131 }
2132 return smk_curacc_shm(shp, may);
2133 }
2134
2135 /**
2136 * smack_shm_shmat - Smack access for shmat
2137 * @shp: the object
2138 * @shmaddr: unused
2139 * @shmflg: access requested
2140 *
2141 * Returns 0 if current has the requested access, error code otherwise
2142 */
2143 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2144 int shmflg)
2145 {
2146 int may;
2147
2148 may = smack_flags_to_may(shmflg);
2149 return smk_curacc_shm(shp, may);
2150 }
2151
2152 /**
2153 * smack_of_sem - the smack pointer for the sem
2154 * @sma: the object
2155 *
2156 * Returns a pointer to the smack value
2157 */
2158 static char *smack_of_sem(struct sem_array *sma)
2159 {
2160 return (char *)sma->sem_perm.security;
2161 }
2162
2163 /**
2164 * smack_sem_alloc_security - Set the security blob for sem
2165 * @sma: the object
2166 *
2167 * Returns 0
2168 */
2169 static int smack_sem_alloc_security(struct sem_array *sma)
2170 {
2171 struct kern_ipc_perm *isp = &sma->sem_perm;
2172
2173 isp->security = smk_of_current();
2174 return 0;
2175 }
2176
2177 /**
2178 * smack_sem_free_security - Clear the security blob for sem
2179 * @sma: the object
2180 *
2181 * Clears the blob pointer
2182 */
2183 static void smack_sem_free_security(struct sem_array *sma)
2184 {
2185 struct kern_ipc_perm *isp = &sma->sem_perm;
2186
2187 isp->security = NULL;
2188 }
2189
2190 /**
2191 * smk_curacc_sem : check if current has access on sem
2192 * @sma : the object
2193 * @access : access requested
2194 *
2195 * Returns 0 if current has the requested access, error code otherwise
2196 */
2197 static int smk_curacc_sem(struct sem_array *sma, int access)
2198 {
2199 char *ssp = smack_of_sem(sma);
2200 struct smk_audit_info ad;
2201
2202 #ifdef CONFIG_AUDIT
2203 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2204 ad.a.u.ipc_id = sma->sem_perm.id;
2205 #endif
2206 return smk_curacc(ssp, access, &ad);
2207 }
2208
2209 /**
2210 * smack_sem_associate - Smack access check for sem
2211 * @sma: the object
2212 * @semflg: access requested
2213 *
2214 * Returns 0 if current has the requested access, error code otherwise
2215 */
2216 static int smack_sem_associate(struct sem_array *sma, int semflg)
2217 {
2218 int may;
2219
2220 may = smack_flags_to_may(semflg);
2221 return smk_curacc_sem(sma, may);
2222 }
2223
2224 /**
2225 * smack_sem_shmctl - Smack access check for sem
2226 * @sma: the object
2227 * @cmd: what it wants to do
2228 *
2229 * Returns 0 if current has the requested access, error code otherwise
2230 */
2231 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2232 {
2233 int may;
2234
2235 switch (cmd) {
2236 case GETPID:
2237 case GETNCNT:
2238 case GETZCNT:
2239 case GETVAL:
2240 case GETALL:
2241 case IPC_STAT:
2242 case SEM_STAT:
2243 may = MAY_READ;
2244 break;
2245 case SETVAL:
2246 case SETALL:
2247 case IPC_RMID:
2248 case IPC_SET:
2249 may = MAY_READWRITE;
2250 break;
2251 case IPC_INFO:
2252 case SEM_INFO:
2253 /*
2254 * System level information
2255 */
2256 return 0;
2257 default:
2258 return -EINVAL;
2259 }
2260
2261 return smk_curacc_sem(sma, may);
2262 }
2263
2264 /**
2265 * smack_sem_semop - Smack checks of semaphore operations
2266 * @sma: the object
2267 * @sops: unused
2268 * @nsops: unused
2269 * @alter: unused
2270 *
2271 * Treated as read and write in all cases.
2272 *
2273 * Returns 0 if access is allowed, error code otherwise
2274 */
2275 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2276 unsigned nsops, int alter)
2277 {
2278 return smk_curacc_sem(sma, MAY_READWRITE);
2279 }
2280
2281 /**
2282 * smack_msg_alloc_security - Set the security blob for msg
2283 * @msq: the object
2284 *
2285 * Returns 0
2286 */
2287 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2288 {
2289 struct kern_ipc_perm *kisp = &msq->q_perm;
2290
2291 kisp->security = smk_of_current();
2292 return 0;
2293 }
2294
2295 /**
2296 * smack_msg_free_security - Clear the security blob for msg
2297 * @msq: the object
2298 *
2299 * Clears the blob pointer
2300 */
2301 static void smack_msg_queue_free_security(struct msg_queue *msq)
2302 {
2303 struct kern_ipc_perm *kisp = &msq->q_perm;
2304
2305 kisp->security = NULL;
2306 }
2307
2308 /**
2309 * smack_of_msq - the smack pointer for the msq
2310 * @msq: the object
2311 *
2312 * Returns a pointer to the smack value
2313 */
2314 static char *smack_of_msq(struct msg_queue *msq)
2315 {
2316 return (char *)msq->q_perm.security;
2317 }
2318
2319 /**
2320 * smk_curacc_msq : helper to check if current has access on msq
2321 * @msq : the msq
2322 * @access : access requested
2323 *
2324 * return 0 if current has access, error otherwise
2325 */
2326 static int smk_curacc_msq(struct msg_queue *msq, int access)
2327 {
2328 char *msp = smack_of_msq(msq);
2329 struct smk_audit_info ad;
2330
2331 #ifdef CONFIG_AUDIT
2332 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2333 ad.a.u.ipc_id = msq->q_perm.id;
2334 #endif
2335 return smk_curacc(msp, access, &ad);
2336 }
2337
2338 /**
2339 * smack_msg_queue_associate - Smack access check for msg_queue
2340 * @msq: the object
2341 * @msqflg: access requested
2342 *
2343 * Returns 0 if current has the requested access, error code otherwise
2344 */
2345 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2346 {
2347 int may;
2348
2349 may = smack_flags_to_may(msqflg);
2350 return smk_curacc_msq(msq, may);
2351 }
2352
2353 /**
2354 * smack_msg_queue_msgctl - Smack access check for msg_queue
2355 * @msq: the object
2356 * @cmd: what it wants to do
2357 *
2358 * Returns 0 if current has the requested access, error code otherwise
2359 */
2360 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2361 {
2362 int may;
2363
2364 switch (cmd) {
2365 case IPC_STAT:
2366 case MSG_STAT:
2367 may = MAY_READ;
2368 break;
2369 case IPC_SET:
2370 case IPC_RMID:
2371 may = MAY_READWRITE;
2372 break;
2373 case IPC_INFO:
2374 case MSG_INFO:
2375 /*
2376 * System level information
2377 */
2378 return 0;
2379 default:
2380 return -EINVAL;
2381 }
2382
2383 return smk_curacc_msq(msq, may);
2384 }
2385
2386 /**
2387 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2388 * @msq: the object
2389 * @msg: unused
2390 * @msqflg: access requested
2391 *
2392 * Returns 0 if current has the requested access, error code otherwise
2393 */
2394 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2395 int msqflg)
2396 {
2397 int may;
2398
2399 may = smack_flags_to_may(msqflg);
2400 return smk_curacc_msq(msq, may);
2401 }
2402
2403 /**
2404 * smack_msg_queue_msgsnd - Smack access check for msg_queue
2405 * @msq: the object
2406 * @msg: unused
2407 * @target: unused
2408 * @type: unused
2409 * @mode: unused
2410 *
2411 * Returns 0 if current has read and write access, error code otherwise
2412 */
2413 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2414 struct task_struct *target, long type, int mode)
2415 {
2416 return smk_curacc_msq(msq, MAY_READWRITE);
2417 }
2418
2419 /**
2420 * smack_ipc_permission - Smack access for ipc_permission()
2421 * @ipp: the object permissions
2422 * @flag: access requested
2423 *
2424 * Returns 0 if current has read and write access, error code otherwise
2425 */
2426 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2427 {
2428 char *isp = ipp->security;
2429 int may = smack_flags_to_may(flag);
2430 struct smk_audit_info ad;
2431
2432 #ifdef CONFIG_AUDIT
2433 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2434 ad.a.u.ipc_id = ipp->id;
2435 #endif
2436 return smk_curacc(isp, may, &ad);
2437 }
2438
2439 /**
2440 * smack_ipc_getsecid - Extract smack security id
2441 * @ipp: the object permissions
2442 * @secid: where result will be saved
2443 */
2444 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2445 {
2446 char *smack = ipp->security;
2447
2448 *secid = smack_to_secid(smack);
2449 }
2450
2451 /**
2452 * smack_d_instantiate - Make sure the blob is correct on an inode
2453 * @opt_dentry: dentry where inode will be attached
2454 * @inode: the object
2455 *
2456 * Set the inode's security blob if it hasn't been done already.
2457 */
2458 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2459 {
2460 struct super_block *sbp;
2461 struct superblock_smack *sbsp;
2462 struct inode_smack *isp;
2463 char *csp = smk_of_current();
2464 char *fetched;
2465 char *final;
2466 char trattr[TRANS_TRUE_SIZE];
2467 int transflag = 0;
2468 int rc;
2469 struct dentry *dp;
2470
2471 if (inode == NULL)
2472 return;
2473
2474 isp = inode->i_security;
2475
2476 mutex_lock(&isp->smk_lock);
2477 /*
2478 * If the inode is already instantiated
2479 * take the quick way out
2480 */
2481 if (isp->smk_flags & SMK_INODE_INSTANT)
2482 goto unlockandout;
2483
2484 sbp = inode->i_sb;
2485 sbsp = sbp->s_security;
2486 /*
2487 * We're going to use the superblock default label
2488 * if there's no label on the file.
2489 */
2490 final = sbsp->smk_default;
2491
2492 /*
2493 * If this is the root inode the superblock
2494 * may be in the process of initialization.
2495 * If that is the case use the root value out
2496 * of the superblock.
2497 */
2498 if (opt_dentry->d_parent == opt_dentry) {
2499 isp->smk_inode = sbsp->smk_root;
2500 isp->smk_flags |= SMK_INODE_INSTANT;
2501 goto unlockandout;
2502 }
2503
2504 /*
2505 * This is pretty hackish.
2506 * Casey says that we shouldn't have to do
2507 * file system specific code, but it does help
2508 * with keeping it simple.
2509 */
2510 switch (sbp->s_magic) {
2511 case SMACK_MAGIC:
2512 /*
2513 * Casey says that it's a little embarrassing
2514 * that the smack file system doesn't do
2515 * extended attributes.
2516 */
2517 final = smack_known_star.smk_known;
2518 break;
2519 case PIPEFS_MAGIC:
2520 /*
2521 * Casey says pipes are easy (?)
2522 */
2523 final = smack_known_star.smk_known;
2524 break;
2525 case DEVPTS_SUPER_MAGIC:
2526 /*
2527 * devpts seems content with the label of the task.
2528 * Programs that change smack have to treat the
2529 * pty with respect.
2530 */
2531 final = csp;
2532 break;
2533 case SOCKFS_MAGIC:
2534 /*
2535 * Socket access is controlled by the socket
2536 * structures associated with the task involved.
2537 */
2538 final = smack_known_star.smk_known;
2539 break;
2540 case PROC_SUPER_MAGIC:
2541 /*
2542 * Casey says procfs appears not to care.
2543 * The superblock default suffices.
2544 */
2545 break;
2546 case TMPFS_MAGIC:
2547 /*
2548 * Device labels should come from the filesystem,
2549 * but watch out, because they're volitile,
2550 * getting recreated on every reboot.
2551 */
2552 final = smack_known_star.smk_known;
2553 /*
2554 * No break.
2555 *
2556 * If a smack value has been set we want to use it,
2557 * but since tmpfs isn't giving us the opportunity
2558 * to set mount options simulate setting the
2559 * superblock default.
2560 */
2561 default:
2562 /*
2563 * This isn't an understood special case.
2564 * Get the value from the xattr.
2565 */
2566
2567 /*
2568 * UNIX domain sockets use lower level socket data.
2569 */
2570 if (S_ISSOCK(inode->i_mode)) {
2571 final = smack_known_star.smk_known;
2572 break;
2573 }
2574 /*
2575 * No xattr support means, alas, no SMACK label.
2576 * Use the aforeapplied default.
2577 * It would be curious if the label of the task
2578 * does not match that assigned.
2579 */
2580 if (inode->i_op->getxattr == NULL)
2581 break;
2582 /*
2583 * Get the dentry for xattr.
2584 */
2585 dp = dget(opt_dentry);
2586 fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2587 if (fetched != NULL)
2588 final = fetched;
2589
2590 /*
2591 * Transmuting directory
2592 */
2593 if (S_ISDIR(inode->i_mode)) {
2594 /*
2595 * If this is a new directory and the label was
2596 * transmuted when the inode was initialized
2597 * set the transmute attribute on the directory
2598 * and mark the inode.
2599 *
2600 * If there is a transmute attribute on the
2601 * directory mark the inode.
2602 */
2603 if (isp->smk_flags & SMK_INODE_CHANGED) {
2604 isp->smk_flags &= ~SMK_INODE_CHANGED;
2605 rc = inode->i_op->setxattr(dp,
2606 XATTR_NAME_SMACKTRANSMUTE,
2607 TRANS_TRUE, TRANS_TRUE_SIZE,
2608 0);
2609 } else {
2610 rc = inode->i_op->getxattr(dp,
2611 XATTR_NAME_SMACKTRANSMUTE, trattr,
2612 TRANS_TRUE_SIZE);
2613 if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
2614 TRANS_TRUE_SIZE) != 0)
2615 rc = -EINVAL;
2616 }
2617 if (rc >= 0)
2618 transflag = SMK_INODE_TRANSMUTE;
2619 }
2620 isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2621 isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2622
2623 dput(dp);
2624 break;
2625 }
2626
2627 if (final == NULL)
2628 isp->smk_inode = csp;
2629 else
2630 isp->smk_inode = final;
2631
2632 isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2633
2634 unlockandout:
2635 mutex_unlock(&isp->smk_lock);
2636 return;
2637 }
2638
2639 /**
2640 * smack_getprocattr - Smack process attribute access
2641 * @p: the object task
2642 * @name: the name of the attribute in /proc/.../attr
2643 * @value: where to put the result
2644 *
2645 * Places a copy of the task Smack into value
2646 *
2647 * Returns the length of the smack label or an error code
2648 */
2649 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2650 {
2651 char *cp;
2652 int slen;
2653
2654 if (strcmp(name, "current") != 0)
2655 return -EINVAL;
2656
2657 cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2658 if (cp == NULL)
2659 return -ENOMEM;
2660
2661 slen = strlen(cp);
2662 *value = cp;
2663 return slen;
2664 }
2665
2666 /**
2667 * smack_setprocattr - Smack process attribute setting
2668 * @p: the object task
2669 * @name: the name of the attribute in /proc/.../attr
2670 * @value: the value to set
2671 * @size: the size of the value
2672 *
2673 * Sets the Smack value of the task. Only setting self
2674 * is permitted and only with privilege
2675 *
2676 * Returns the length of the smack label or an error code
2677 */
2678 static int smack_setprocattr(struct task_struct *p, char *name,
2679 void *value, size_t size)
2680 {
2681 struct task_smack *tsp;
2682 struct cred *new;
2683 char *newsmack;
2684
2685 /*
2686 * Changing another process' Smack value is too dangerous
2687 * and supports no sane use case.
2688 */
2689 if (p != current)
2690 return -EPERM;
2691
2692 if (!smack_privileged(CAP_MAC_ADMIN))
2693 return -EPERM;
2694
2695 if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
2696 return -EINVAL;
2697
2698 if (strcmp(name, "current") != 0)
2699 return -EINVAL;
2700
2701 newsmack = smk_import(value, size);
2702 if (newsmack == NULL)
2703 return -EINVAL;
2704
2705 /*
2706 * No process is ever allowed the web ("@") label.
2707 */
2708 if (newsmack == smack_known_web.smk_known)
2709 return -EPERM;
2710
2711 new = prepare_creds();
2712 if (new == NULL)
2713 return -ENOMEM;
2714
2715 tsp = new->security;
2716 tsp->smk_task = newsmack;
2717
2718 commit_creds(new);
2719 return size;
2720 }
2721
2722 /**
2723 * smack_unix_stream_connect - Smack access on UDS
2724 * @sock: one sock
2725 * @other: the other sock
2726 * @newsk: unused
2727 *
2728 * Return 0 if a subject with the smack of sock could access
2729 * an object with the smack of other, otherwise an error code
2730 */
2731 static int smack_unix_stream_connect(struct sock *sock,
2732 struct sock *other, struct sock *newsk)
2733 {
2734 struct socket_smack *ssp = sock->sk_security;
2735 struct socket_smack *osp = other->sk_security;
2736 struct socket_smack *nsp = newsk->sk_security;
2737 struct smk_audit_info ad;
2738 int rc = 0;
2739
2740 #ifdef CONFIG_AUDIT
2741 struct lsm_network_audit net;
2742
2743 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2744 smk_ad_setfield_u_net_sk(&ad, other);
2745 #endif
2746
2747 if (!smack_privileged(CAP_MAC_OVERRIDE))
2748 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2749
2750 /*
2751 * Cross reference the peer labels for SO_PEERSEC.
2752 */
2753 if (rc == 0) {
2754 nsp->smk_packet = ssp->smk_out;
2755 ssp->smk_packet = osp->smk_out;
2756 }
2757
2758 return rc;
2759 }
2760
2761 /**
2762 * smack_unix_may_send - Smack access on UDS
2763 * @sock: one socket
2764 * @other: the other socket
2765 *
2766 * Return 0 if a subject with the smack of sock could access
2767 * an object with the smack of other, otherwise an error code
2768 */
2769 static int smack_unix_may_send(struct socket *sock, struct socket *other)
2770 {
2771 struct socket_smack *ssp = sock->sk->sk_security;
2772 struct socket_smack *osp = other->sk->sk_security;
2773 struct smk_audit_info ad;
2774 int rc = 0;
2775
2776 #ifdef CONFIG_AUDIT
2777 struct lsm_network_audit net;
2778
2779 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2780 smk_ad_setfield_u_net_sk(&ad, other->sk);
2781 #endif
2782
2783 if (!smack_privileged(CAP_MAC_OVERRIDE))
2784 rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2785
2786 return rc;
2787 }
2788
2789 /**
2790 * smack_socket_sendmsg - Smack check based on destination host
2791 * @sock: the socket
2792 * @msg: the message
2793 * @size: the size of the message
2794 *
2795 * Return 0 if the current subject can write to the destination
2796 * host. This is only a question if the destination is a single
2797 * label host.
2798 */
2799 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2800 int size)
2801 {
2802 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2803
2804 /*
2805 * Perfectly reasonable for this to be NULL
2806 */
2807 if (sip == NULL || sip->sin_family != AF_INET)
2808 return 0;
2809
2810 return smack_netlabel_send(sock->sk, sip);
2811 }
2812
2813 /**
2814 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2815 * @sap: netlabel secattr
2816 * @ssp: socket security information
2817 *
2818 * Returns a pointer to a Smack label found on the label list.
2819 */
2820 static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
2821 struct socket_smack *ssp)
2822 {
2823 struct smack_known *kp;
2824 char *sp;
2825 int found = 0;
2826
2827 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2828 /*
2829 * Looks like a CIPSO packet.
2830 * If there are flags but no level netlabel isn't
2831 * behaving the way we expect it to.
2832 *
2833 * Look it up in the label table
2834 * Without guidance regarding the smack value
2835 * for the packet fall back on the network
2836 * ambient value.
2837 */
2838 rcu_read_lock();
2839 list_for_each_entry(kp, &smack_known_list, list) {
2840 if (sap->attr.mls.lvl != kp->smk_netlabel.attr.mls.lvl)
2841 continue;
2842 if (memcmp(sap->attr.mls.cat,
2843 kp->smk_netlabel.attr.mls.cat,
2844 SMK_CIPSOLEN) != 0)
2845 continue;
2846 found = 1;
2847 break;
2848 }
2849 rcu_read_unlock();
2850
2851 if (found)
2852 return kp->smk_known;
2853
2854 if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
2855 return smack_known_web.smk_known;
2856 return smack_known_star.smk_known;
2857 }
2858 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
2859 /*
2860 * Looks like a fallback, which gives us a secid.
2861 */
2862 sp = smack_from_secid(sap->attr.secid);
2863 /*
2864 * This has got to be a bug because it is
2865 * impossible to specify a fallback without
2866 * specifying the label, which will ensure
2867 * it has a secid, and the only way to get a
2868 * secid is from a fallback.
2869 */
2870 BUG_ON(sp == NULL);
2871 return sp;
2872 }
2873 /*
2874 * Without guidance regarding the smack value
2875 * for the packet fall back on the network
2876 * ambient value.
2877 */
2878 return smack_net_ambient;
2879 }
2880
2881 /**
2882 * smack_socket_sock_rcv_skb - Smack packet delivery access check
2883 * @sk: socket
2884 * @skb: packet
2885 *
2886 * Returns 0 if the packet should be delivered, an error code otherwise
2887 */
2888 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2889 {
2890 struct netlbl_lsm_secattr secattr;
2891 struct socket_smack *ssp = sk->sk_security;
2892 char *csp;
2893 int rc;
2894 struct smk_audit_info ad;
2895 #ifdef CONFIG_AUDIT
2896 struct lsm_network_audit net;
2897 #endif
2898 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
2899 return 0;
2900
2901 /*
2902 * Translate what netlabel gave us.
2903 */
2904 netlbl_secattr_init(&secattr);
2905
2906 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
2907 if (rc == 0)
2908 csp = smack_from_secattr(&secattr, ssp);
2909 else
2910 csp = smack_net_ambient;
2911
2912 netlbl_secattr_destroy(&secattr);
2913
2914 #ifdef CONFIG_AUDIT
2915 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2916 ad.a.u.net->family = sk->sk_family;
2917 ad.a.u.net->netif = skb->skb_iif;
2918 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2919 #endif
2920 /*
2921 * Receiving a packet requires that the other end
2922 * be able to write here. Read access is not required.
2923 * This is the simplist possible security model
2924 * for networking.
2925 */
2926 rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2927 if (rc != 0)
2928 netlbl_skbuff_err(skb, rc, 0);
2929 return rc;
2930 }
2931
2932 /**
2933 * smack_socket_getpeersec_stream - pull in packet label
2934 * @sock: the socket
2935 * @optval: user's destination
2936 * @optlen: size thereof
2937 * @len: max thereof
2938 *
2939 * returns zero on success, an error code otherwise
2940 */
2941 static int smack_socket_getpeersec_stream(struct socket *sock,
2942 char __user *optval,
2943 int __user *optlen, unsigned len)
2944 {
2945 struct socket_smack *ssp;
2946 char *rcp = "";
2947 int slen = 1;
2948 int rc = 0;
2949
2950 ssp = sock->sk->sk_security;
2951 if (ssp->smk_packet != NULL) {
2952 rcp = ssp->smk_packet;
2953 slen = strlen(rcp) + 1;
2954 }
2955
2956 if (slen > len)
2957 rc = -ERANGE;
2958 else if (copy_to_user(optval, rcp, slen) != 0)
2959 rc = -EFAULT;
2960
2961 if (put_user(slen, optlen) != 0)
2962 rc = -EFAULT;
2963
2964 return rc;
2965 }
2966
2967
2968 /**
2969 * smack_socket_getpeersec_dgram - pull in packet label
2970 * @sock: the peer socket
2971 * @skb: packet data
2972 * @secid: pointer to where to put the secid of the packet
2973 *
2974 * Sets the netlabel socket state on sk from parent
2975 */
2976 static int smack_socket_getpeersec_dgram(struct socket *sock,
2977 struct sk_buff *skb, u32 *secid)
2978
2979 {
2980 struct netlbl_lsm_secattr secattr;
2981 struct socket_smack *ssp = NULL;
2982 char *sp;
2983 int family = PF_UNSPEC;
2984 u32 s = 0; /* 0 is the invalid secid */
2985 int rc;
2986
2987 if (skb != NULL) {
2988 if (skb->protocol == htons(ETH_P_IP))
2989 family = PF_INET;
2990 else if (skb->protocol == htons(ETH_P_IPV6))
2991 family = PF_INET6;
2992 }
2993 if (family == PF_UNSPEC && sock != NULL)
2994 family = sock->sk->sk_family;
2995
2996 if (family == PF_UNIX) {
2997 ssp = sock->sk->sk_security;
2998 s = smack_to_secid(ssp->smk_out);
2999 } else if (family == PF_INET || family == PF_INET6) {
3000 /*
3001 * Translate what netlabel gave us.
3002 */
3003 if (sock != NULL && sock->sk != NULL)
3004 ssp = sock->sk->sk_security;
3005 netlbl_secattr_init(&secattr);
3006 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3007 if (rc == 0) {
3008 sp = smack_from_secattr(&secattr, ssp);
3009 s = smack_to_secid(sp);
3010 }
3011 netlbl_secattr_destroy(&secattr);
3012 }
3013 *secid = s;
3014 if (s == 0)
3015 return -EINVAL;
3016 return 0;
3017 }
3018
3019 /**
3020 * smack_sock_graft - Initialize a newly created socket with an existing sock
3021 * @sk: child sock
3022 * @parent: parent socket
3023 *
3024 * Set the smk_{in,out} state of an existing sock based on the process that
3025 * is creating the new socket.
3026 */
3027 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3028 {
3029 struct socket_smack *ssp;
3030
3031 if (sk == NULL ||
3032 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3033 return;
3034
3035 ssp = sk->sk_security;
3036 ssp->smk_in = ssp->smk_out = smk_of_current();
3037 /* cssp->smk_packet is already set in smack_inet_csk_clone() */
3038 }
3039
3040 /**
3041 * smack_inet_conn_request - Smack access check on connect
3042 * @sk: socket involved
3043 * @skb: packet
3044 * @req: unused
3045 *
3046 * Returns 0 if a task with the packet label could write to
3047 * the socket, otherwise an error code
3048 */
3049 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3050 struct request_sock *req)
3051 {
3052 u16 family = sk->sk_family;
3053 struct smack_known *skp;
3054 struct socket_smack *ssp = sk->sk_security;
3055 struct netlbl_lsm_secattr secattr;
3056 struct sockaddr_in addr;
3057 struct iphdr *hdr;
3058 char *sp;
3059 char *hsp;
3060 int rc;
3061 struct smk_audit_info ad;
3062 #ifdef CONFIG_AUDIT
3063 struct lsm_network_audit net;
3064 #endif
3065
3066 /* handle mapped IPv4 packets arriving via IPv6 sockets */
3067 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3068 family = PF_INET;
3069
3070 netlbl_secattr_init(&secattr);
3071 rc = netlbl_skbuff_getattr(skb, family, &secattr);
3072 if (rc == 0)
3073 sp = smack_from_secattr(&secattr, ssp);
3074 else
3075 sp = smack_known_huh.smk_known;
3076 netlbl_secattr_destroy(&secattr);
3077
3078 #ifdef CONFIG_AUDIT
3079 smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3080 ad.a.u.net->family = family;
3081 ad.a.u.net->netif = skb->skb_iif;
3082 ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3083 #endif
3084 /*
3085 * Receiving a packet requires that the other end be able to write
3086 * here. Read access is not required.
3087 */
3088 rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
3089 if (rc != 0)
3090 return rc;
3091
3092 /*
3093 * Save the peer's label in the request_sock so we can later setup
3094 * smk_packet in the child socket so that SO_PEERCRED can report it.
3095 */
3096 req->peer_secid = smack_to_secid(sp);
3097
3098 /*
3099 * We need to decide if we want to label the incoming connection here
3100 * if we do we only need to label the request_sock and the stack will
3101 * propagate the wire-label to the sock when it is created.
3102 */
3103 hdr = ip_hdr(skb);
3104 addr.sin_addr.s_addr = hdr->saddr;
3105 rcu_read_lock();
3106 hsp = smack_host_label(&addr);
3107 rcu_read_unlock();
3108
3109 if (hsp == NULL) {
3110 skp = smk_find_entry(sp);
3111 rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3112 } else
3113 netlbl_req_delattr(req);
3114
3115 return rc;
3116 }
3117
3118 /**
3119 * smack_inet_csk_clone - Copy the connection information to the new socket
3120 * @sk: the new socket
3121 * @req: the connection's request_sock
3122 *
3123 * Transfer the connection's peer label to the newly created socket.
3124 */
3125 static void smack_inet_csk_clone(struct sock *sk,
3126 const struct request_sock *req)
3127 {
3128 struct socket_smack *ssp = sk->sk_security;
3129
3130 if (req->peer_secid != 0)
3131 ssp->smk_packet = smack_from_secid(req->peer_secid);
3132 else
3133 ssp->smk_packet = NULL;
3134 }
3135
3136 /*
3137 * Key management security hooks
3138 *
3139 * Casey has not tested key support very heavily.
3140 * The permission check is most likely too restrictive.
3141 * If you care about keys please have a look.
3142 */
3143 #ifdef CONFIG_KEYS
3144
3145 /**
3146 * smack_key_alloc - Set the key security blob
3147 * @key: object
3148 * @cred: the credentials to use
3149 * @flags: unused
3150 *
3151 * No allocation required
3152 *
3153 * Returns 0
3154 */
3155 static int smack_key_alloc(struct key *key, const struct cred *cred,
3156 unsigned long flags)
3157 {
3158 key->security = smk_of_task(cred->security);
3159 return 0;
3160 }
3161
3162 /**
3163 * smack_key_free - Clear the key security blob
3164 * @key: the object
3165 *
3166 * Clear the blob pointer
3167 */
3168 static void smack_key_free(struct key *key)
3169 {
3170 key->security = NULL;
3171 }
3172
3173 /*
3174 * smack_key_permission - Smack access on a key
3175 * @key_ref: gets to the object
3176 * @cred: the credentials to use
3177 * @perm: unused
3178 *
3179 * Return 0 if the task has read and write to the object,
3180 * an error code otherwise
3181 */
3182 static int smack_key_permission(key_ref_t key_ref,
3183 const struct cred *cred, key_perm_t perm)
3184 {
3185 struct key *keyp;
3186 struct smk_audit_info ad;
3187 char *tsp = smk_of_task(cred->security);
3188
3189 keyp = key_ref_to_ptr(key_ref);
3190 if (keyp == NULL)
3191 return -EINVAL;
3192 /*
3193 * If the key hasn't been initialized give it access so that
3194 * it may do so.
3195 */
3196 if (keyp->security == NULL)
3197 return 0;
3198 /*
3199 * This should not occur
3200 */
3201 if (tsp == NULL)
3202 return -EACCES;
3203 #ifdef CONFIG_AUDIT
3204 smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3205 ad.a.u.key_struct.key = keyp->serial;
3206 ad.a.u.key_struct.key_desc = keyp->description;
3207 #endif
3208 return smk_access(tsp, keyp->security,
3209 MAY_READWRITE, &ad);
3210 }
3211 #endif /* CONFIG_KEYS */
3212
3213 /*
3214 * Smack Audit hooks
3215 *
3216 * Audit requires a unique representation of each Smack specific
3217 * rule. This unique representation is used to distinguish the
3218 * object to be audited from remaining kernel objects and also
3219 * works as a glue between the audit hooks.
3220 *
3221 * Since repository entries are added but never deleted, we'll use
3222 * the smack_known label address related to the given audit rule as
3223 * the needed unique representation. This also better fits the smack
3224 * model where nearly everything is a label.
3225 */
3226 #ifdef CONFIG_AUDIT
3227
3228 /**
3229 * smack_audit_rule_init - Initialize a smack audit rule
3230 * @field: audit rule fields given from user-space (audit.h)
3231 * @op: required testing operator (=, !=, >, <, ...)
3232 * @rulestr: smack label to be audited
3233 * @vrule: pointer to save our own audit rule representation
3234 *
3235 * Prepare to audit cases where (@field @op @rulestr) is true.
3236 * The label to be audited is created if necessay.
3237 */
3238 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3239 {
3240 char **rule = (char **)vrule;
3241 *rule = NULL;
3242
3243 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3244 return -EINVAL;
3245
3246 if (op != Audit_equal && op != Audit_not_equal)
3247 return -EINVAL;
3248
3249 *rule = smk_import(rulestr, 0);
3250
3251 return 0;
3252 }
3253
3254 /**
3255 * smack_audit_rule_known - Distinguish Smack audit rules
3256 * @krule: rule of interest, in Audit kernel representation format
3257 *
3258 * This is used to filter Smack rules from remaining Audit ones.
3259 * If it's proved that this rule belongs to us, the
3260 * audit_rule_match hook will be called to do the final judgement.
3261 */
3262 static int smack_audit_rule_known(struct audit_krule *krule)
3263 {
3264 struct audit_field *f;
3265 int i;
3266
3267 for (i = 0; i < krule->field_count; i++) {
3268 f = &krule->fields[i];
3269
3270 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3271 return 1;
3272 }
3273
3274 return 0;
3275 }
3276
3277 /**
3278 * smack_audit_rule_match - Audit given object ?
3279 * @secid: security id for identifying the object to test
3280 * @field: audit rule flags given from user-space
3281 * @op: required testing operator
3282 * @vrule: smack internal rule presentation
3283 * @actx: audit context associated with the check
3284 *
3285 * The core Audit hook. It's used to take the decision of
3286 * whether to audit or not to audit a given object.
3287 */
3288 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3289 struct audit_context *actx)
3290 {
3291 char *smack;
3292 char *rule = vrule;
3293
3294 if (!rule) {
3295 audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR,
3296 "Smack: missing rule\n");
3297 return -ENOENT;
3298 }
3299
3300 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3301 return 0;
3302
3303 smack = smack_from_secid(secid);
3304
3305 /*
3306 * No need to do string comparisons. If a match occurs,
3307 * both pointers will point to the same smack_known
3308 * label.
3309 */
3310 if (op == Audit_equal)
3311 return (rule == smack);
3312 if (op == Audit_not_equal)
3313 return (rule != smack);
3314
3315 return 0;
3316 }
3317
3318 /**
3319 * smack_audit_rule_free - free smack rule representation
3320 * @vrule: rule to be freed.
3321 *
3322 * No memory was allocated.
3323 */
3324 static void smack_audit_rule_free(void *vrule)
3325 {
3326 /* No-op */
3327 }
3328
3329 #endif /* CONFIG_AUDIT */
3330
3331 /**
3332 * smack_secid_to_secctx - return the smack label for a secid
3333 * @secid: incoming integer
3334 * @secdata: destination
3335 * @seclen: how long it is
3336 *
3337 * Exists for networking code.
3338 */
3339 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3340 {
3341 char *sp = smack_from_secid(secid);
3342
3343 if (secdata)
3344 *secdata = sp;
3345 *seclen = strlen(sp);
3346 return 0;
3347 }
3348
3349 /**
3350 * smack_secctx_to_secid - return the secid for a smack label
3351 * @secdata: smack label
3352 * @seclen: how long result is
3353 * @secid: outgoing integer
3354 *
3355 * Exists for audit and networking code.
3356 */
3357 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3358 {
3359 *secid = smack_to_secid(secdata);
3360 return 0;
3361 }
3362
3363 /**
3364 * smack_release_secctx - don't do anything.
3365 * @secdata: unused
3366 * @seclen: unused
3367 *
3368 * Exists to make sure nothing gets done, and properly
3369 */
3370 static void smack_release_secctx(char *secdata, u32 seclen)
3371 {
3372 }
3373
3374 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3375 {
3376 return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3377 }
3378
3379 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3380 {
3381 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3382 }
3383
3384 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3385 {
3386 int len = 0;
3387 len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3388
3389 if (len < 0)
3390 return len;
3391 *ctxlen = len;
3392 return 0;
3393 }
3394
3395 struct security_operations smack_ops = {
3396 .name = "smack",
3397
3398 .ptrace_access_check = smack_ptrace_access_check,
3399 .ptrace_traceme = smack_ptrace_traceme,
3400 .syslog = smack_syslog,
3401
3402 .sb_alloc_security = smack_sb_alloc_security,
3403 .sb_free_security = smack_sb_free_security,
3404 .sb_copy_data = smack_sb_copy_data,
3405 .sb_kern_mount = smack_sb_kern_mount,
3406 .sb_statfs = smack_sb_statfs,
3407 .sb_mount = smack_sb_mount,
3408 .sb_umount = smack_sb_umount,
3409
3410 .bprm_set_creds = smack_bprm_set_creds,
3411 .bprm_committing_creds = smack_bprm_committing_creds,
3412 .bprm_secureexec = smack_bprm_secureexec,
3413
3414 .inode_alloc_security = smack_inode_alloc_security,
3415 .inode_free_security = smack_inode_free_security,
3416 .inode_init_security = smack_inode_init_security,
3417 .inode_link = smack_inode_link,
3418 .inode_unlink = smack_inode_unlink,
3419 .inode_rmdir = smack_inode_rmdir,
3420 .inode_rename = smack_inode_rename,
3421 .inode_permission = smack_inode_permission,
3422 .inode_setattr = smack_inode_setattr,
3423 .inode_getattr = smack_inode_getattr,
3424 .inode_setxattr = smack_inode_setxattr,
3425 .inode_post_setxattr = smack_inode_post_setxattr,
3426 .inode_getxattr = smack_inode_getxattr,
3427 .inode_removexattr = smack_inode_removexattr,
3428 .inode_getsecurity = smack_inode_getsecurity,
3429 .inode_setsecurity = smack_inode_setsecurity,
3430 .inode_listsecurity = smack_inode_listsecurity,
3431 .inode_getsecid = smack_inode_getsecid,
3432
3433 .file_permission = smack_file_permission,
3434 .file_alloc_security = smack_file_alloc_security,
3435 .file_free_security = smack_file_free_security,
3436 .file_ioctl = smack_file_ioctl,
3437 .file_lock = smack_file_lock,
3438 .file_fcntl = smack_file_fcntl,
3439 .mmap_file = smack_mmap_file,
3440 .mmap_addr = cap_mmap_addr,
3441 .file_set_fowner = smack_file_set_fowner,
3442 .file_send_sigiotask = smack_file_send_sigiotask,
3443 .file_receive = smack_file_receive,
3444
3445 .file_open = smack_file_open,
3446
3447 .cred_alloc_blank = smack_cred_alloc_blank,
3448 .cred_free = smack_cred_free,
3449 .cred_prepare = smack_cred_prepare,
3450 .cred_transfer = smack_cred_transfer,
3451 .kernel_act_as = smack_kernel_act_as,
3452 .kernel_create_files_as = smack_kernel_create_files_as,
3453 .task_setpgid = smack_task_setpgid,
3454 .task_getpgid = smack_task_getpgid,
3455 .task_getsid = smack_task_getsid,
3456 .task_getsecid = smack_task_getsecid,
3457 .task_setnice = smack_task_setnice,
3458 .task_setioprio = smack_task_setioprio,
3459 .task_getioprio = smack_task_getioprio,
3460 .task_setscheduler = smack_task_setscheduler,
3461 .task_getscheduler = smack_task_getscheduler,
3462 .task_movememory = smack_task_movememory,
3463 .task_kill = smack_task_kill,
3464 .task_wait = smack_task_wait,
3465 .task_to_inode = smack_task_to_inode,
3466
3467 .ipc_permission = smack_ipc_permission,
3468 .ipc_getsecid = smack_ipc_getsecid,
3469
3470 .msg_msg_alloc_security = smack_msg_msg_alloc_security,
3471 .msg_msg_free_security = smack_msg_msg_free_security,
3472
3473 .msg_queue_alloc_security = smack_msg_queue_alloc_security,
3474 .msg_queue_free_security = smack_msg_queue_free_security,
3475 .msg_queue_associate = smack_msg_queue_associate,
3476 .msg_queue_msgctl = smack_msg_queue_msgctl,
3477 .msg_queue_msgsnd = smack_msg_queue_msgsnd,
3478 .msg_queue_msgrcv = smack_msg_queue_msgrcv,
3479
3480 .shm_alloc_security = smack_shm_alloc_security,
3481 .shm_free_security = smack_shm_free_security,
3482 .shm_associate = smack_shm_associate,
3483 .shm_shmctl = smack_shm_shmctl,
3484 .shm_shmat = smack_shm_shmat,
3485
3486 .sem_alloc_security = smack_sem_alloc_security,
3487 .sem_free_security = smack_sem_free_security,
3488 .sem_associate = smack_sem_associate,
3489 .sem_semctl = smack_sem_semctl,
3490 .sem_semop = smack_sem_semop,
3491
3492 .d_instantiate = smack_d_instantiate,
3493
3494 .getprocattr = smack_getprocattr,
3495 .setprocattr = smack_setprocattr,
3496
3497 .unix_stream_connect = smack_unix_stream_connect,
3498 .unix_may_send = smack_unix_may_send,
3499
3500 .socket_post_create = smack_socket_post_create,
3501 .socket_connect = smack_socket_connect,
3502 .socket_sendmsg = smack_socket_sendmsg,
3503 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
3504 .socket_getpeersec_stream = smack_socket_getpeersec_stream,
3505 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
3506 .sk_alloc_security = smack_sk_alloc_security,
3507 .sk_free_security = smack_sk_free_security,
3508 .sock_graft = smack_sock_graft,
3509 .inet_conn_request = smack_inet_conn_request,
3510 .inet_csk_clone = smack_inet_csk_clone,
3511
3512 /* key management security hooks */
3513 #ifdef CONFIG_KEYS
3514 .key_alloc = smack_key_alloc,
3515 .key_free = smack_key_free,
3516 .key_permission = smack_key_permission,
3517 #endif /* CONFIG_KEYS */
3518
3519 /* Audit hooks */
3520 #ifdef CONFIG_AUDIT
3521 .audit_rule_init = smack_audit_rule_init,
3522 .audit_rule_known = smack_audit_rule_known,
3523 .audit_rule_match = smack_audit_rule_match,
3524 .audit_rule_free = smack_audit_rule_free,
3525 #endif /* CONFIG_AUDIT */
3526
3527 .secid_to_secctx = smack_secid_to_secctx,
3528 .secctx_to_secid = smack_secctx_to_secid,
3529 .release_secctx = smack_release_secctx,
3530 .inode_notifysecctx = smack_inode_notifysecctx,
3531 .inode_setsecctx = smack_inode_setsecctx,
3532 .inode_getsecctx = smack_inode_getsecctx,
3533 };
3534
3535
3536 static __init void init_smack_known_list(void)
3537 {
3538 /*
3539 * Initialize rule list locks
3540 */
3541 mutex_init(&smack_known_huh.smk_rules_lock);
3542 mutex_init(&smack_known_hat.smk_rules_lock);
3543 mutex_init(&smack_known_floor.smk_rules_lock);
3544 mutex_init(&smack_known_star.smk_rules_lock);
3545 mutex_init(&smack_known_invalid.smk_rules_lock);
3546 mutex_init(&smack_known_web.smk_rules_lock);
3547 /*
3548 * Initialize rule lists
3549 */
3550 INIT_LIST_HEAD(&smack_known_huh.smk_rules);
3551 INIT_LIST_HEAD(&smack_known_hat.smk_rules);
3552 INIT_LIST_HEAD(&smack_known_star.smk_rules);
3553 INIT_LIST_HEAD(&smack_known_floor.smk_rules);
3554 INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
3555 INIT_LIST_HEAD(&smack_known_web.smk_rules);
3556 /*
3557 * Create the known labels list
3558 */
3559 list_add(&smack_known_huh.list, &smack_known_list);
3560 list_add(&smack_known_hat.list, &smack_known_list);
3561 list_add(&smack_known_star.list, &smack_known_list);
3562 list_add(&smack_known_floor.list, &smack_known_list);
3563 list_add(&smack_known_invalid.list, &smack_known_list);
3564 list_add(&smack_known_web.list, &smack_known_list);
3565 }
3566
3567 /**
3568 * smack_init - initialize the smack system
3569 *
3570 * Returns 0
3571 */
3572 static __init int smack_init(void)
3573 {
3574 struct cred *cred;
3575 struct task_smack *tsp;
3576
3577 if (!security_module_enable(&smack_ops))
3578 return 0;
3579
3580 tsp = new_task_smack(smack_known_floor.smk_known,
3581 smack_known_floor.smk_known, GFP_KERNEL);
3582 if (tsp == NULL)
3583 return -ENOMEM;
3584
3585 printk(KERN_INFO "Smack: Initializing.\n");
3586
3587 /*
3588 * Set the security state for the initial task.
3589 */
3590 cred = (struct cred *) current->cred;
3591 cred->security = tsp;
3592
3593 /* initialize the smack_known_list */
3594 init_smack_known_list();
3595
3596 /*
3597 * Register with LSM
3598 */
3599 if (register_security(&smack_ops))
3600 panic("smack: Unable to register with kernel.\n");
3601
3602 return 0;
3603 }
3604
3605 /*
3606 * Smack requires early initialization in order to label
3607 * all processes and objects when they are created.
3608 */
3609 security_initcall(smack_init);