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Merge ../linus
[linux-2.6/openmoko-kernel/knife-kernel.git] / kernel / auditfilter.c
blob6a9a5c5a4e7db9f03cb175e5448cf9a3bf209dc7
1 /* auditfilter.c -- filtering of audit events
2 *
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
26 #include <linux/fs.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/inotify.h>
31 #include <linux/selinux.h>
32 #include "audit.h"
33
34 /*
35 * Locking model:
36 *
37 * audit_filter_mutex:
38 * Synchronizes writes and blocking reads of audit's filterlist
39 * data. Rcu is used to traverse the filterlist and access
40 * contents of structs audit_entry, audit_watch and opaque
41 * selinux rules during filtering. If modified, these structures
42 * must be copied and replace their counterparts in the filterlist.
43 * An audit_parent struct is not accessed during filtering, so may
44 * be written directly provided audit_filter_mutex is held.
45 */
46
47 /*
48 * Reference counting:
49 *
50 * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
51 * event. Each audit_watch holds a reference to its associated parent.
52 *
53 * audit_watch: if added to lists, lifetime is from audit_init_watch() to
54 * audit_remove_watch(). Additionally, an audit_watch may exist
55 * temporarily to assist in searching existing filter data. Each
56 * audit_krule holds a reference to its associated watch.
57 */
58
59 struct audit_parent {
60 struct list_head ilist; /* entry in inotify registration list */
61 struct list_head watches; /* associated watches */
62 struct inotify_watch wdata; /* inotify watch data */
63 unsigned flags; /* status flags */
64 };
65
66 /*
67 * audit_parent status flags:
68 *
69 * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
70 * a filesystem event to ensure we're adding audit watches to a valid parent.
71 * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
72 * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
73 * we can receive while holding nameidata.
74 */
75 #define AUDIT_PARENT_INVALID 0x001
76
77 /* Audit filter lists, defined in <linux/audit.h> */
78 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
79 LIST_HEAD_INIT(audit_filter_list[0]),
80 LIST_HEAD_INIT(audit_filter_list[1]),
81 LIST_HEAD_INIT(audit_filter_list[2]),
82 LIST_HEAD_INIT(audit_filter_list[3]),
83 LIST_HEAD_INIT(audit_filter_list[4]),
84 LIST_HEAD_INIT(audit_filter_list[5]),
85 #if AUDIT_NR_FILTERS != 6
86 #error Fix audit_filter_list initialiser
87 #endif
88 };
89
90 static DEFINE_MUTEX(audit_filter_mutex);
91
92 /* Inotify handle */
93 extern struct inotify_handle *audit_ih;
94
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
97
98 void audit_free_parent(struct inotify_watch *i_watch)
99 {
100 struct audit_parent *parent;
101
102 parent = container_of(i_watch, struct audit_parent, wdata);
103 WARN_ON(!list_empty(&parent->watches));
104 kfree(parent);
105 }
106
107 static inline void audit_get_watch(struct audit_watch *watch)
108 {
109 atomic_inc(&watch->count);
110 }
111
112 static void audit_put_watch(struct audit_watch *watch)
113 {
114 if (atomic_dec_and_test(&watch->count)) {
115 WARN_ON(watch->parent);
116 WARN_ON(!list_empty(&watch->rules));
117 kfree(watch->path);
118 kfree(watch);
119 }
120 }
121
122 static void audit_remove_watch(struct audit_watch *watch)
123 {
124 list_del(&watch->wlist);
125 put_inotify_watch(&watch->parent->wdata);
126 watch->parent = NULL;
127 audit_put_watch(watch); /* match initial get */
128 }
129
130 static inline void audit_free_rule(struct audit_entry *e)
131 {
132 int i;
133
134 /* some rules don't have associated watches */
135 if (e->rule.watch)
136 audit_put_watch(e->rule.watch);
137 if (e->rule.fields)
138 for (i = 0; i < e->rule.field_count; i++) {
139 struct audit_field *f = &e->rule.fields[i];
140 kfree(f->se_str);
141 selinux_audit_rule_free(f->se_rule);
142 }
143 kfree(e->rule.fields);
144 kfree(e->rule.filterkey);
145 kfree(e);
146 }
147
148 static inline void audit_free_rule_rcu(struct rcu_head *head)
149 {
150 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
151 audit_free_rule(e);
152 }
153
154 /* Initialize a parent watch entry. */
155 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
156 {
157 struct audit_parent *parent;
158 s32 wd;
159
160 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
161 if (unlikely(!parent))
162 return ERR_PTR(-ENOMEM);
163
164 INIT_LIST_HEAD(&parent->watches);
165 parent->flags = 0;
166
167 inotify_init_watch(&parent->wdata);
168 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
169 get_inotify_watch(&parent->wdata);
170 wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
171 AUDIT_IN_WATCH);
172 if (wd < 0) {
173 audit_free_parent(&parent->wdata);
174 return ERR_PTR(wd);
175 }
176
177 return parent;
178 }
179
180 /* Initialize a watch entry. */
181 static struct audit_watch *audit_init_watch(char *path)
182 {
183 struct audit_watch *watch;
184
185 watch = kzalloc(sizeof(*watch), GFP_KERNEL);
186 if (unlikely(!watch))
187 return ERR_PTR(-ENOMEM);
188
189 INIT_LIST_HEAD(&watch->rules);
190 atomic_set(&watch->count, 1);
191 watch->path = path;
192 watch->dev = (dev_t)-1;
193 watch->ino = (unsigned long)-1;
194
195 return watch;
196 }
197
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry *audit_init_entry(u32 field_count)
200 {
201 struct audit_entry *entry;
202 struct audit_field *fields;
203
204 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
205 if (unlikely(!entry))
206 return NULL;
207
208 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
209 if (unlikely(!fields)) {
210 kfree(entry);
211 return NULL;
212 }
213 entry->rule.fields = fields;
214
215 return entry;
216 }
217
218 /* Unpack a filter field's string representation from user-space
219 * buffer. */
220 static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
221 {
222 char *str;
223
224 if (!*bufp || (len == 0) || (len > *remain))
225 return ERR_PTR(-EINVAL);
226
227 /* Of the currently implemented string fields, PATH_MAX
228 * defines the longest valid length.
229 */
230 if (len > PATH_MAX)
231 return ERR_PTR(-ENAMETOOLONG);
232
233 str = kmalloc(len + 1, GFP_KERNEL);
234 if (unlikely(!str))
235 return ERR_PTR(-ENOMEM);
236
237 memcpy(str, *bufp, len);
238 str[len] = 0;
239 *bufp += len;
240 *remain -= len;
241
242 return str;
243 }
244
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule *krule,
247 struct audit_field *f)
248 {
249 if (krule->listnr != AUDIT_FILTER_EXIT ||
250 krule->watch || krule->inode_f)
251 return -EINVAL;
252
253 krule->inode_f = f;
254 return 0;
255 }
256
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
259 u32 op)
260 {
261 struct audit_watch *watch;
262
263 if (!audit_ih)
264 return -EOPNOTSUPP;
265
266 if (path[0] != '/' || path[len-1] == '/' ||
267 krule->listnr != AUDIT_FILTER_EXIT ||
268 op & ~AUDIT_EQUAL ||
269 krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
270 return -EINVAL;
271
272 watch = audit_init_watch(path);
273 if (unlikely(IS_ERR(watch)))
274 return PTR_ERR(watch);
275
276 audit_get_watch(watch);
277 krule->watch = watch;
278
279 return 0;
280 }
281
282 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
283
284 int __init audit_register_class(int class, unsigned *list)
285 {
286 __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
287 if (!p)
288 return -ENOMEM;
289 while (*list != ~0U) {
290 unsigned n = *list++;
291 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
292 kfree(p);
293 return -EINVAL;
294 }
295 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
296 }
297 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
298 kfree(p);
299 return -EINVAL;
300 }
301 classes[class] = p;
302 return 0;
303 }
304
305 /* Common user-space to kernel rule translation. */
306 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
307 {
308 unsigned listnr;
309 struct audit_entry *entry;
310 int i, err;
311
312 err = -EINVAL;
313 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
314 switch(listnr) {
315 default:
316 goto exit_err;
317 case AUDIT_FILTER_USER:
318 case AUDIT_FILTER_TYPE:
319 #ifdef CONFIG_AUDITSYSCALL
320 case AUDIT_FILTER_ENTRY:
321 case AUDIT_FILTER_EXIT:
322 case AUDIT_FILTER_TASK:
323 #endif
324 ;
325 }
326 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
327 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
328 goto exit_err;
329 }
330 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
331 goto exit_err;
332 if (rule->field_count > AUDIT_MAX_FIELDS)
333 goto exit_err;
334
335 err = -ENOMEM;
336 entry = audit_init_entry(rule->field_count);
337 if (!entry)
338 goto exit_err;
339
340 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
341 entry->rule.listnr = listnr;
342 entry->rule.action = rule->action;
343 entry->rule.field_count = rule->field_count;
344
345 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
346 entry->rule.mask[i] = rule->mask[i];
347
348 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
349 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
350 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
351 __u32 *class;
352
353 if (!(*p & AUDIT_BIT(bit)))
354 continue;
355 *p &= ~AUDIT_BIT(bit);
356 class = classes[i];
357 if (class) {
358 int j;
359 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
360 entry->rule.mask[j] |= class[j];
361 }
362 }
363
364 return entry;
365
366 exit_err:
367 return ERR_PTR(err);
368 }
369
370 /* Translate struct audit_rule to kernel's rule respresentation.
371 * Exists for backward compatibility with userspace. */
372 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
373 {
374 struct audit_entry *entry;
375 struct audit_field *f;
376 int err = 0;
377 int i;
378
379 entry = audit_to_entry_common(rule);
380 if (IS_ERR(entry))
381 goto exit_nofree;
382
383 for (i = 0; i < rule->field_count; i++) {
384 struct audit_field *f = &entry->rule.fields[i];
385
386 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
387 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
388 f->val = rule->values[i];
389
390 err = -EINVAL;
391 switch(f->type) {
392 default:
393 goto exit_free;
394 case AUDIT_PID:
395 case AUDIT_UID:
396 case AUDIT_EUID:
397 case AUDIT_SUID:
398 case AUDIT_FSUID:
399 case AUDIT_GID:
400 case AUDIT_EGID:
401 case AUDIT_SGID:
402 case AUDIT_FSGID:
403 case AUDIT_LOGINUID:
404 case AUDIT_PERS:
405 case AUDIT_ARCH:
406 case AUDIT_MSGTYPE:
407 case AUDIT_DEVMAJOR:
408 case AUDIT_DEVMINOR:
409 case AUDIT_EXIT:
410 case AUDIT_SUCCESS:
411 case AUDIT_ARG0:
412 case AUDIT_ARG1:
413 case AUDIT_ARG2:
414 case AUDIT_ARG3:
415 break;
416 case AUDIT_INODE:
417 err = audit_to_inode(&entry->rule, f);
418 if (err)
419 goto exit_free;
420 break;
421 }
422
423 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
424
425 /* Support for legacy operators where
426 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
427 if (f->op & AUDIT_NEGATE)
428 f->op = AUDIT_NOT_EQUAL;
429 else if (!f->op)
430 f->op = AUDIT_EQUAL;
431 else if (f->op == AUDIT_OPERATORS) {
432 err = -EINVAL;
433 goto exit_free;
434 }
435 }
436
437 f = entry->rule.inode_f;
438 if (f) {
439 switch(f->op) {
440 case AUDIT_NOT_EQUAL:
441 entry->rule.inode_f = NULL;
442 case AUDIT_EQUAL:
443 break;
444 default:
445 err = -EINVAL;
446 goto exit_free;
447 }
448 }
449
450 exit_nofree:
451 return entry;
452
453 exit_free:
454 audit_free_rule(entry);
455 return ERR_PTR(err);
456 }
457
458 /* Translate struct audit_rule_data to kernel's rule respresentation. */
459 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
460 size_t datasz)
461 {
462 int err = 0;
463 struct audit_entry *entry;
464 struct audit_field *f;
465 void *bufp;
466 size_t remain = datasz - sizeof(struct audit_rule_data);
467 int i;
468 char *str;
469
470 entry = audit_to_entry_common((struct audit_rule *)data);
471 if (IS_ERR(entry))
472 goto exit_nofree;
473
474 bufp = data->buf;
475 entry->rule.vers_ops = 2;
476 for (i = 0; i < data->field_count; i++) {
477 struct audit_field *f = &entry->rule.fields[i];
478
479 err = -EINVAL;
480 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
481 data->fieldflags[i] & ~AUDIT_OPERATORS)
482 goto exit_free;
483
484 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
485 f->type = data->fields[i];
486 f->val = data->values[i];
487 f->se_str = NULL;
488 f->se_rule = NULL;
489 switch(f->type) {
490 case AUDIT_PID:
491 case AUDIT_UID:
492 case AUDIT_EUID:
493 case AUDIT_SUID:
494 case AUDIT_FSUID:
495 case AUDIT_GID:
496 case AUDIT_EGID:
497 case AUDIT_SGID:
498 case AUDIT_FSGID:
499 case AUDIT_LOGINUID:
500 case AUDIT_PERS:
501 case AUDIT_ARCH:
502 case AUDIT_MSGTYPE:
503 case AUDIT_PPID:
504 case AUDIT_DEVMAJOR:
505 case AUDIT_DEVMINOR:
506 case AUDIT_EXIT:
507 case AUDIT_SUCCESS:
508 case AUDIT_ARG0:
509 case AUDIT_ARG1:
510 case AUDIT_ARG2:
511 case AUDIT_ARG3:
512 break;
513 case AUDIT_SUBJ_USER:
514 case AUDIT_SUBJ_ROLE:
515 case AUDIT_SUBJ_TYPE:
516 case AUDIT_SUBJ_SEN:
517 case AUDIT_SUBJ_CLR:
518 case AUDIT_OBJ_USER:
519 case AUDIT_OBJ_ROLE:
520 case AUDIT_OBJ_TYPE:
521 case AUDIT_OBJ_LEV_LOW:
522 case AUDIT_OBJ_LEV_HIGH:
523 str = audit_unpack_string(&bufp, &remain, f->val);
524 if (IS_ERR(str))
525 goto exit_free;
526 entry->rule.buflen += f->val;
527
528 err = selinux_audit_rule_init(f->type, f->op, str,
529 &f->se_rule);
530 /* Keep currently invalid fields around in case they
531 * become valid after a policy reload. */
532 if (err == -EINVAL) {
533 printk(KERN_WARNING "audit rule for selinux "
534 "\'%s\' is invalid\n", str);
535 err = 0;
536 }
537 if (err) {
538 kfree(str);
539 goto exit_free;
540 } else
541 f->se_str = str;
542 break;
543 case AUDIT_WATCH:
544 str = audit_unpack_string(&bufp, &remain, f->val);
545 if (IS_ERR(str))
546 goto exit_free;
547 entry->rule.buflen += f->val;
548
549 err = audit_to_watch(&entry->rule, str, f->val, f->op);
550 if (err) {
551 kfree(str);
552 goto exit_free;
553 }
554 break;
555 case AUDIT_INODE:
556 err = audit_to_inode(&entry->rule, f);
557 if (err)
558 goto exit_free;
559 break;
560 case AUDIT_FILTERKEY:
561 err = -EINVAL;
562 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
563 goto exit_free;
564 str = audit_unpack_string(&bufp, &remain, f->val);
565 if (IS_ERR(str))
566 goto exit_free;
567 entry->rule.buflen += f->val;
568 entry->rule.filterkey = str;
569 break;
570 default:
571 goto exit_free;
572 }
573 }
574
575 f = entry->rule.inode_f;
576 if (f) {
577 switch(f->op) {
578 case AUDIT_NOT_EQUAL:
579 entry->rule.inode_f = NULL;
580 case AUDIT_EQUAL:
581 break;
582 default:
583 err = -EINVAL;
584 goto exit_free;
585 }
586 }
587
588 exit_nofree:
589 return entry;
590
591 exit_free:
592 audit_free_rule(entry);
593 return ERR_PTR(err);
594 }
595
596 /* Pack a filter field's string representation into data block. */
597 static inline size_t audit_pack_string(void **bufp, char *str)
598 {
599 size_t len = strlen(str);
600
601 memcpy(*bufp, str, len);
602 *bufp += len;
603
604 return len;
605 }
606
607 /* Translate kernel rule respresentation to struct audit_rule.
608 * Exists for backward compatibility with userspace. */
609 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
610 {
611 struct audit_rule *rule;
612 int i;
613
614 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
615 if (unlikely(!rule))
616 return NULL;
617 memset(rule, 0, sizeof(*rule));
618
619 rule->flags = krule->flags | krule->listnr;
620 rule->action = krule->action;
621 rule->field_count = krule->field_count;
622 for (i = 0; i < rule->field_count; i++) {
623 rule->values[i] = krule->fields[i].val;
624 rule->fields[i] = krule->fields[i].type;
625
626 if (krule->vers_ops == 1) {
627 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
628 rule->fields[i] |= AUDIT_NEGATE;
629 } else {
630 rule->fields[i] |= krule->fields[i].op;
631 }
632 }
633 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
634
635 return rule;
636 }
637
638 /* Translate kernel rule respresentation to struct audit_rule_data. */
639 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
640 {
641 struct audit_rule_data *data;
642 void *bufp;
643 int i;
644
645 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
646 if (unlikely(!data))
647 return NULL;
648 memset(data, 0, sizeof(*data));
649
650 data->flags = krule->flags | krule->listnr;
651 data->action = krule->action;
652 data->field_count = krule->field_count;
653 bufp = data->buf;
654 for (i = 0; i < data->field_count; i++) {
655 struct audit_field *f = &krule->fields[i];
656
657 data->fields[i] = f->type;
658 data->fieldflags[i] = f->op;
659 switch(f->type) {
660 case AUDIT_SUBJ_USER:
661 case AUDIT_SUBJ_ROLE:
662 case AUDIT_SUBJ_TYPE:
663 case AUDIT_SUBJ_SEN:
664 case AUDIT_SUBJ_CLR:
665 case AUDIT_OBJ_USER:
666 case AUDIT_OBJ_ROLE:
667 case AUDIT_OBJ_TYPE:
668 case AUDIT_OBJ_LEV_LOW:
669 case AUDIT_OBJ_LEV_HIGH:
670 data->buflen += data->values[i] =
671 audit_pack_string(&bufp, f->se_str);
672 break;
673 case AUDIT_WATCH:
674 data->buflen += data->values[i] =
675 audit_pack_string(&bufp, krule->watch->path);
676 break;
677 case AUDIT_FILTERKEY:
678 data->buflen += data->values[i] =
679 audit_pack_string(&bufp, krule->filterkey);
680 break;
681 default:
682 data->values[i] = f->val;
683 }
684 }
685 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
686
687 return data;
688 }
689
690 /* Compare two rules in kernel format. Considered success if rules
691 * don't match. */
692 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
693 {
694 int i;
695
696 if (a->flags != b->flags ||
697 a->listnr != b->listnr ||
698 a->action != b->action ||
699 a->field_count != b->field_count)
700 return 1;
701
702 for (i = 0; i < a->field_count; i++) {
703 if (a->fields[i].type != b->fields[i].type ||
704 a->fields[i].op != b->fields[i].op)
705 return 1;
706
707 switch(a->fields[i].type) {
708 case AUDIT_SUBJ_USER:
709 case AUDIT_SUBJ_ROLE:
710 case AUDIT_SUBJ_TYPE:
711 case AUDIT_SUBJ_SEN:
712 case AUDIT_SUBJ_CLR:
713 case AUDIT_OBJ_USER:
714 case AUDIT_OBJ_ROLE:
715 case AUDIT_OBJ_TYPE:
716 case AUDIT_OBJ_LEV_LOW:
717 case AUDIT_OBJ_LEV_HIGH:
718 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
719 return 1;
720 break;
721 case AUDIT_WATCH:
722 if (strcmp(a->watch->path, b->watch->path))
723 return 1;
724 break;
725 case AUDIT_FILTERKEY:
726 /* both filterkeys exist based on above type compare */
727 if (strcmp(a->filterkey, b->filterkey))
728 return 1;
729 break;
730 default:
731 if (a->fields[i].val != b->fields[i].val)
732 return 1;
733 }
734 }
735
736 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
737 if (a->mask[i] != b->mask[i])
738 return 1;
739
740 return 0;
741 }
742
743 /* Duplicate the given audit watch. The new watch's rules list is initialized
744 * to an empty list and wlist is undefined. */
745 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
746 {
747 char *path;
748 struct audit_watch *new;
749
750 path = kstrdup(old->path, GFP_KERNEL);
751 if (unlikely(!path))
752 return ERR_PTR(-ENOMEM);
753
754 new = audit_init_watch(path);
755 if (unlikely(IS_ERR(new))) {
756 kfree(path);
757 goto out;
758 }
759
760 new->dev = old->dev;
761 new->ino = old->ino;
762 get_inotify_watch(&old->parent->wdata);
763 new->parent = old->parent;
764
765 out:
766 return new;
767 }
768
769 /* Duplicate selinux field information. The se_rule is opaque, so must be
770 * re-initialized. */
771 static inline int audit_dupe_selinux_field(struct audit_field *df,
772 struct audit_field *sf)
773 {
774 int ret = 0;
775 char *se_str;
776
777 /* our own copy of se_str */
778 se_str = kstrdup(sf->se_str, GFP_KERNEL);
779 if (unlikely(IS_ERR(se_str)))
780 return -ENOMEM;
781 df->se_str = se_str;
782
783 /* our own (refreshed) copy of se_rule */
784 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
785 &df->se_rule);
786 /* Keep currently invalid fields around in case they
787 * become valid after a policy reload. */
788 if (ret == -EINVAL) {
789 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
790 "invalid\n", df->se_str);
791 ret = 0;
792 }
793
794 return ret;
795 }
796
797 /* Duplicate an audit rule. This will be a deep copy with the exception
798 * of the watch - that pointer is carried over. The selinux specific fields
799 * will be updated in the copy. The point is to be able to replace the old
800 * rule with the new rule in the filterlist, then free the old rule.
801 * The rlist element is undefined; list manipulations are handled apart from
802 * the initial copy. */
803 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
804 struct audit_watch *watch)
805 {
806 u32 fcount = old->field_count;
807 struct audit_entry *entry;
808 struct audit_krule *new;
809 char *fk;
810 int i, err = 0;
811
812 entry = audit_init_entry(fcount);
813 if (unlikely(!entry))
814 return ERR_PTR(-ENOMEM);
815
816 new = &entry->rule;
817 new->vers_ops = old->vers_ops;
818 new->flags = old->flags;
819 new->listnr = old->listnr;
820 new->action = old->action;
821 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
822 new->mask[i] = old->mask[i];
823 new->buflen = old->buflen;
824 new->inode_f = old->inode_f;
825 new->watch = NULL;
826 new->field_count = old->field_count;
827 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
828
829 /* deep copy this information, updating the se_rule fields, because
830 * the originals will all be freed when the old rule is freed. */
831 for (i = 0; i < fcount; i++) {
832 switch (new->fields[i].type) {
833 case AUDIT_SUBJ_USER:
834 case AUDIT_SUBJ_ROLE:
835 case AUDIT_SUBJ_TYPE:
836 case AUDIT_SUBJ_SEN:
837 case AUDIT_SUBJ_CLR:
838 case AUDIT_OBJ_USER:
839 case AUDIT_OBJ_ROLE:
840 case AUDIT_OBJ_TYPE:
841 case AUDIT_OBJ_LEV_LOW:
842 case AUDIT_OBJ_LEV_HIGH:
843 err = audit_dupe_selinux_field(&new->fields[i],
844 &old->fields[i]);
845 break;
846 case AUDIT_FILTERKEY:
847 fk = kstrdup(old->filterkey, GFP_KERNEL);
848 if (unlikely(!fk))
849 err = -ENOMEM;
850 else
851 new->filterkey = fk;
852 }
853 if (err) {
854 audit_free_rule(entry);
855 return ERR_PTR(err);
856 }
857 }
858
859 if (watch) {
860 audit_get_watch(watch);
861 new->watch = watch;
862 }
863
864 return entry;
865 }
866
867 /* Update inode info in audit rules based on filesystem event. */
868 static void audit_update_watch(struct audit_parent *parent,
869 const char *dname, dev_t dev,
870 unsigned long ino, unsigned invalidating)
871 {
872 struct audit_watch *owatch, *nwatch, *nextw;
873 struct audit_krule *r, *nextr;
874 struct audit_entry *oentry, *nentry;
875 struct audit_buffer *ab;
876
877 mutex_lock(&audit_filter_mutex);
878 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
879 if (audit_compare_dname_path(dname, owatch->path, NULL))
880 continue;
881
882 /* If the update involves invalidating rules, do the inode-based
883 * filtering now, so we don't omit records. */
884 if (invalidating &&
885 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
886 audit_set_auditable(current->audit_context);
887
888 nwatch = audit_dupe_watch(owatch);
889 if (unlikely(IS_ERR(nwatch))) {
890 mutex_unlock(&audit_filter_mutex);
891 audit_panic("error updating watch, skipping");
892 return;
893 }
894 nwatch->dev = dev;
895 nwatch->ino = ino;
896
897 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
898
899 oentry = container_of(r, struct audit_entry, rule);
900 list_del(&oentry->rule.rlist);
901 list_del_rcu(&oentry->list);
902
903 nentry = audit_dupe_rule(&oentry->rule, nwatch);
904 if (unlikely(IS_ERR(nentry)))
905 audit_panic("error updating watch, removing");
906 else {
907 int h = audit_hash_ino((u32)ino);
908 list_add(&nentry->rule.rlist, &nwatch->rules);
909 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
910 }
911
912 call_rcu(&oentry->rcu, audit_free_rule_rcu);
913 }
914
915 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
916 audit_log_format(ab, "audit updated rules specifying watch=");
917 audit_log_untrustedstring(ab, owatch->path);
918 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
919 audit_log_end(ab);
920
921 audit_remove_watch(owatch);
922 goto add_watch_to_parent; /* event applies to a single watch */
923 }
924 mutex_unlock(&audit_filter_mutex);
925 return;
926
927 add_watch_to_parent:
928 list_add(&nwatch->wlist, &parent->watches);
929 mutex_unlock(&audit_filter_mutex);
930 return;
931 }
932
933 /* Remove all watches & rules associated with a parent that is going away. */
934 static void audit_remove_parent_watches(struct audit_parent *parent)
935 {
936 struct audit_watch *w, *nextw;
937 struct audit_krule *r, *nextr;
938 struct audit_entry *e;
939
940 mutex_lock(&audit_filter_mutex);
941 parent->flags |= AUDIT_PARENT_INVALID;
942 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
943 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
944 e = container_of(r, struct audit_entry, rule);
945 list_del(&r->rlist);
946 list_del_rcu(&e->list);
947 call_rcu(&e->rcu, audit_free_rule_rcu);
948
949 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
950 "audit implicitly removed rule from list=%d\n",
951 AUDIT_FILTER_EXIT);
952 }
953 audit_remove_watch(w);
954 }
955 mutex_unlock(&audit_filter_mutex);
956 }
957
958 /* Unregister inotify watches for parents on in_list.
959 * Generates an IN_IGNORED event. */
960 static void audit_inotify_unregister(struct list_head *in_list)
961 {
962 struct audit_parent *p, *n;
963
964 list_for_each_entry_safe(p, n, in_list, ilist) {
965 list_del(&p->ilist);
966 inotify_rm_watch(audit_ih, &p->wdata);
967 /* the put matching the get in audit_do_del_rule() */
968 put_inotify_watch(&p->wdata);
969 }
970 }
971
972 /* Find an existing audit rule.
973 * Caller must hold audit_filter_mutex to prevent stale rule data. */
974 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
975 struct list_head *list)
976 {
977 struct audit_entry *e, *found = NULL;
978 int h;
979
980 if (entry->rule.watch) {
981 /* we don't know the inode number, so must walk entire hash */
982 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
983 list = &audit_inode_hash[h];
984 list_for_each_entry(e, list, list)
985 if (!audit_compare_rule(&entry->rule, &e->rule)) {
986 found = e;
987 goto out;
988 }
989 }
990 goto out;
991 }
992
993 list_for_each_entry(e, list, list)
994 if (!audit_compare_rule(&entry->rule, &e->rule)) {
995 found = e;
996 goto out;
997 }
998
999 out:
1000 return found;
1001 }
1002
1003 /* Get path information necessary for adding watches. */
1004 static int audit_get_nd(char *path, struct nameidata **ndp,
1005 struct nameidata **ndw)
1006 {
1007 struct nameidata *ndparent, *ndwatch;
1008 int err;
1009
1010 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1011 if (unlikely(!ndparent))
1012 return -ENOMEM;
1013
1014 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1015 if (unlikely(!ndwatch)) {
1016 kfree(ndparent);
1017 return -ENOMEM;
1018 }
1019
1020 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1021 if (err) {
1022 kfree(ndparent);
1023 kfree(ndwatch);
1024 return err;
1025 }
1026
1027 err = path_lookup(path, 0, ndwatch);
1028 if (err) {
1029 kfree(ndwatch);
1030 ndwatch = NULL;
1031 }
1032
1033 *ndp = ndparent;
1034 *ndw = ndwatch;
1035
1036 return 0;
1037 }
1038
1039 /* Release resources used for watch path information. */
1040 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1041 {
1042 if (ndp) {
1043 path_release(ndp);
1044 kfree(ndp);
1045 }
1046 if (ndw) {
1047 path_release(ndw);
1048 kfree(ndw);
1049 }
1050 }
1051
1052 /* Associate the given rule with an existing parent inotify_watch.
1053 * Caller must hold audit_filter_mutex. */
1054 static void audit_add_to_parent(struct audit_krule *krule,
1055 struct audit_parent *parent)
1056 {
1057 struct audit_watch *w, *watch = krule->watch;
1058 int watch_found = 0;
1059
1060 list_for_each_entry(w, &parent->watches, wlist) {
1061 if (strcmp(watch->path, w->path))
1062 continue;
1063
1064 watch_found = 1;
1065
1066 /* put krule's and initial refs to temporary watch */
1067 audit_put_watch(watch);
1068 audit_put_watch(watch);
1069
1070 audit_get_watch(w);
1071 krule->watch = watch = w;
1072 break;
1073 }
1074
1075 if (!watch_found) {
1076 get_inotify_watch(&parent->wdata);
1077 watch->parent = parent;
1078
1079 list_add(&watch->wlist, &parent->watches);
1080 }
1081 list_add(&krule->rlist, &watch->rules);
1082 }
1083
1084 /* Find a matching watch entry, or add this one.
1085 * Caller must hold audit_filter_mutex. */
1086 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1087 struct nameidata *ndw)
1088 {
1089 struct audit_watch *watch = krule->watch;
1090 struct inotify_watch *i_watch;
1091 struct audit_parent *parent;
1092 int ret = 0;
1093
1094 /* update watch filter fields */
1095 if (ndw) {
1096 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1097 watch->ino = ndw->dentry->d_inode->i_ino;
1098 }
1099
1100 /* The audit_filter_mutex must not be held during inotify calls because
1101 * we hold it during inotify event callback processing. If an existing
1102 * inotify watch is found, inotify_find_watch() grabs a reference before
1103 * returning.
1104 */
1105 mutex_unlock(&audit_filter_mutex);
1106
1107 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1108 parent = audit_init_parent(ndp);
1109 if (IS_ERR(parent)) {
1110 /* caller expects mutex locked */
1111 mutex_lock(&audit_filter_mutex);
1112 return PTR_ERR(parent);
1113 }
1114 } else
1115 parent = container_of(i_watch, struct audit_parent, wdata);
1116
1117 mutex_lock(&audit_filter_mutex);
1118
1119 /* parent was moved before we took audit_filter_mutex */
1120 if (parent->flags & AUDIT_PARENT_INVALID)
1121 ret = -ENOENT;
1122 else
1123 audit_add_to_parent(krule, parent);
1124
1125 /* match get in audit_init_parent or inotify_find_watch */
1126 put_inotify_watch(&parent->wdata);
1127 return ret;
1128 }
1129
1130 /* Add rule to given filterlist if not a duplicate. */
1131 static inline int audit_add_rule(struct audit_entry *entry,
1132 struct list_head *list)
1133 {
1134 struct audit_entry *e;
1135 struct audit_field *inode_f = entry->rule.inode_f;
1136 struct audit_watch *watch = entry->rule.watch;
1137 struct nameidata *ndp, *ndw;
1138 int h, err, putnd_needed = 0;
1139 #ifdef CONFIG_AUDITSYSCALL
1140 int dont_count = 0;
1141
1142 /* If either of these, don't count towards total */
1143 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1144 entry->rule.listnr == AUDIT_FILTER_TYPE)
1145 dont_count = 1;
1146 #endif
1147
1148 if (inode_f) {
1149 h = audit_hash_ino(inode_f->val);
1150 list = &audit_inode_hash[h];
1151 }
1152
1153 mutex_lock(&audit_filter_mutex);
1154 e = audit_find_rule(entry, list);
1155 mutex_unlock(&audit_filter_mutex);
1156 if (e) {
1157 err = -EEXIST;
1158 goto error;
1159 }
1160
1161 /* Avoid calling path_lookup under audit_filter_mutex. */
1162 if (watch) {
1163 err = audit_get_nd(watch->path, &ndp, &ndw);
1164 if (err)
1165 goto error;
1166 putnd_needed = 1;
1167 }
1168
1169 mutex_lock(&audit_filter_mutex);
1170 if (watch) {
1171 /* audit_filter_mutex is dropped and re-taken during this call */
1172 err = audit_add_watch(&entry->rule, ndp, ndw);
1173 if (err) {
1174 mutex_unlock(&audit_filter_mutex);
1175 goto error;
1176 }
1177 h = audit_hash_ino((u32)watch->ino);
1178 list = &audit_inode_hash[h];
1179 }
1180
1181 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1182 list_add_rcu(&entry->list, list);
1183 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1184 } else {
1185 list_add_tail_rcu(&entry->list, list);
1186 }
1187 #ifdef CONFIG_AUDITSYSCALL
1188 if (!dont_count)
1189 audit_n_rules++;
1190 #endif
1191 mutex_unlock(&audit_filter_mutex);
1192
1193 if (putnd_needed)
1194 audit_put_nd(ndp, ndw);
1195
1196 return 0;
1197
1198 error:
1199 if (putnd_needed)
1200 audit_put_nd(ndp, ndw);
1201 if (watch)
1202 audit_put_watch(watch); /* tmp watch, matches initial get */
1203 return err;
1204 }
1205
1206 /* Remove an existing rule from filterlist. */
1207 static inline int audit_del_rule(struct audit_entry *entry,
1208 struct list_head *list)
1209 {
1210 struct audit_entry *e;
1211 struct audit_field *inode_f = entry->rule.inode_f;
1212 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1213 LIST_HEAD(inotify_list);
1214 int h, ret = 0;
1215 #ifdef CONFIG_AUDITSYSCALL
1216 int dont_count = 0;
1217
1218 /* If either of these, don't count towards total */
1219 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1220 entry->rule.listnr == AUDIT_FILTER_TYPE)
1221 dont_count = 1;
1222 #endif
1223
1224 if (inode_f) {
1225 h = audit_hash_ino(inode_f->val);
1226 list = &audit_inode_hash[h];
1227 }
1228
1229 mutex_lock(&audit_filter_mutex);
1230 e = audit_find_rule(entry, list);
1231 if (!e) {
1232 mutex_unlock(&audit_filter_mutex);
1233 ret = -ENOENT;
1234 goto out;
1235 }
1236
1237 watch = e->rule.watch;
1238 if (watch) {
1239 struct audit_parent *parent = watch->parent;
1240
1241 list_del(&e->rule.rlist);
1242
1243 if (list_empty(&watch->rules)) {
1244 audit_remove_watch(watch);
1245
1246 if (list_empty(&parent->watches)) {
1247 /* Put parent on the inotify un-registration
1248 * list. Grab a reference before releasing
1249 * audit_filter_mutex, to be released in
1250 * audit_inotify_unregister(). */
1251 list_add(&parent->ilist, &inotify_list);
1252 get_inotify_watch(&parent->wdata);
1253 }
1254 }
1255 }
1256
1257 list_del_rcu(&e->list);
1258 call_rcu(&e->rcu, audit_free_rule_rcu);
1259
1260 #ifdef CONFIG_AUDITSYSCALL
1261 if (!dont_count)
1262 audit_n_rules--;
1263 #endif
1264 mutex_unlock(&audit_filter_mutex);
1265
1266 if (!list_empty(&inotify_list))
1267 audit_inotify_unregister(&inotify_list);
1268
1269 out:
1270 if (tmp_watch)
1271 audit_put_watch(tmp_watch); /* match initial get */
1272
1273 return ret;
1274 }
1275
1276 /* List rules using struct audit_rule. Exists for backward
1277 * compatibility with userspace. */
1278 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1279 {
1280 struct sk_buff *skb;
1281 struct audit_entry *entry;
1282 int i;
1283
1284 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1285 * iterator to sync with list writers. */
1286 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1287 list_for_each_entry(entry, &audit_filter_list[i], list) {
1288 struct audit_rule *rule;
1289
1290 rule = audit_krule_to_rule(&entry->rule);
1291 if (unlikely(!rule))
1292 break;
1293 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1294 rule, sizeof(*rule));
1295 if (skb)
1296 skb_queue_tail(q, skb);
1297 kfree(rule);
1298 }
1299 }
1300 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1301 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1302 struct audit_rule *rule;
1303
1304 rule = audit_krule_to_rule(&entry->rule);
1305 if (unlikely(!rule))
1306 break;
1307 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1308 rule, sizeof(*rule));
1309 if (skb)
1310 skb_queue_tail(q, skb);
1311 kfree(rule);
1312 }
1313 }
1314 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1315 if (skb)
1316 skb_queue_tail(q, skb);
1317 }
1318
1319 /* List rules using struct audit_rule_data. */
1320 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1321 {
1322 struct sk_buff *skb;
1323 struct audit_entry *e;
1324 int i;
1325
1326 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1327 * iterator to sync with list writers. */
1328 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1329 list_for_each_entry(e, &audit_filter_list[i], list) {
1330 struct audit_rule_data *data;
1331
1332 data = audit_krule_to_data(&e->rule);
1333 if (unlikely(!data))
1334 break;
1335 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1336 data, sizeof(*data) + data->buflen);
1337 if (skb)
1338 skb_queue_tail(q, skb);
1339 kfree(data);
1340 }
1341 }
1342 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1343 list_for_each_entry(e, &audit_inode_hash[i], list) {
1344 struct audit_rule_data *data;
1345
1346 data = audit_krule_to_data(&e->rule);
1347 if (unlikely(!data))
1348 break;
1349 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1350 data, sizeof(*data) + data->buflen);
1351 if (skb)
1352 skb_queue_tail(q, skb);
1353 kfree(data);
1354 }
1355 }
1356 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1357 if (skb)
1358 skb_queue_tail(q, skb);
1359 }
1360
1361 /* Log rule additions and removals */
1362 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1363 struct audit_krule *rule, int res)
1364 {
1365 struct audit_buffer *ab;
1366
1367 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1368 if (!ab)
1369 return;
1370 audit_log_format(ab, "auid=%u", loginuid);
1371 if (sid) {
1372 char *ctx = NULL;
1373 u32 len;
1374 if (selinux_ctxid_to_string(sid, &ctx, &len))
1375 audit_log_format(ab, " ssid=%u", sid);
1376 else
1377 audit_log_format(ab, " subj=%s", ctx);
1378 kfree(ctx);
1379 }
1380 audit_log_format(ab, " %s rule key=", action);
1381 if (rule->filterkey)
1382 audit_log_untrustedstring(ab, rule->filterkey);
1383 else
1384 audit_log_format(ab, "(null)");
1385 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1386 audit_log_end(ab);
1387 }
1388
1389 /**
1390 * audit_receive_filter - apply all rules to the specified message type
1391 * @type: audit message type
1392 * @pid: target pid for netlink audit messages
1393 * @uid: target uid for netlink audit messages
1394 * @seq: netlink audit message sequence (serial) number
1395 * @data: payload data
1396 * @datasz: size of payload data
1397 * @loginuid: loginuid of sender
1398 * @sid: SE Linux Security ID of sender
1399 */
1400 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1401 size_t datasz, uid_t loginuid, u32 sid)
1402 {
1403 struct task_struct *tsk;
1404 struct audit_netlink_list *dest;
1405 int err = 0;
1406 struct audit_entry *entry;
1407
1408 switch (type) {
1409 case AUDIT_LIST:
1410 case AUDIT_LIST_RULES:
1411 /* We can't just spew out the rules here because we might fill
1412 * the available socket buffer space and deadlock waiting for
1413 * auditctl to read from it... which isn't ever going to
1414 * happen if we're actually running in the context of auditctl
1415 * trying to _send_ the stuff */
1416
1417 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1418 if (!dest)
1419 return -ENOMEM;
1420 dest->pid = pid;
1421 skb_queue_head_init(&dest->q);
1422
1423 mutex_lock(&audit_filter_mutex);
1424 if (type == AUDIT_LIST)
1425 audit_list(pid, seq, &dest->q);
1426 else
1427 audit_list_rules(pid, seq, &dest->q);
1428 mutex_unlock(&audit_filter_mutex);
1429
1430 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1431 if (IS_ERR(tsk)) {
1432 skb_queue_purge(&dest->q);
1433 kfree(dest);
1434 err = PTR_ERR(tsk);
1435 }
1436 break;
1437 case AUDIT_ADD:
1438 case AUDIT_ADD_RULE:
1439 if (type == AUDIT_ADD)
1440 entry = audit_rule_to_entry(data);
1441 else
1442 entry = audit_data_to_entry(data, datasz);
1443 if (IS_ERR(entry))
1444 return PTR_ERR(entry);
1445
1446 err = audit_add_rule(entry,
1447 &audit_filter_list[entry->rule.listnr]);
1448 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1449
1450 if (err)
1451 audit_free_rule(entry);
1452 break;
1453 case AUDIT_DEL:
1454 case AUDIT_DEL_RULE:
1455 if (type == AUDIT_DEL)
1456 entry = audit_rule_to_entry(data);
1457 else
1458 entry = audit_data_to_entry(data, datasz);
1459 if (IS_ERR(entry))
1460 return PTR_ERR(entry);
1461
1462 err = audit_del_rule(entry,
1463 &audit_filter_list[entry->rule.listnr]);
1464 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1465 !err);
1466
1467 audit_free_rule(entry);
1468 break;
1469 default:
1470 return -EINVAL;
1471 }
1472
1473 return err;
1474 }
1475
1476 int audit_comparator(const u32 left, const u32 op, const u32 right)
1477 {
1478 switch (op) {
1479 case AUDIT_EQUAL:
1480 return (left == right);
1481 case AUDIT_NOT_EQUAL:
1482 return (left != right);
1483 case AUDIT_LESS_THAN:
1484 return (left < right);
1485 case AUDIT_LESS_THAN_OR_EQUAL:
1486 return (left <= right);
1487 case AUDIT_GREATER_THAN:
1488 return (left > right);
1489 case AUDIT_GREATER_THAN_OR_EQUAL:
1490 return (left >= right);
1491 }
1492 BUG();
1493 return 0;
1494 }
1495
1496 /* Compare given dentry name with last component in given path,
1497 * return of 0 indicates a match. */
1498 int audit_compare_dname_path(const char *dname, const char *path,
1499 int *dirlen)
1500 {
1501 int dlen, plen;
1502 const char *p;
1503
1504 if (!dname || !path)
1505 return 1;
1506
1507 dlen = strlen(dname);
1508 plen = strlen(path);
1509 if (plen < dlen)
1510 return 1;
1511
1512 /* disregard trailing slashes */
1513 p = path + plen - 1;
1514 while ((*p == '/') && (p > path))
1515 p--;
1516
1517 /* find last path component */
1518 p = p - dlen + 1;
1519 if (p < path)
1520 return 1;
1521 else if (p > path) {
1522 if (*--p != '/')
1523 return 1;
1524 else
1525 p++;
1526 }
1527
1528 /* return length of path's directory component */
1529 if (dirlen)
1530 *dirlen = p - path;
1531 return strncmp(p, dname, dlen);
1532 }
1533
1534 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1535 struct audit_krule *rule,
1536 enum audit_state *state)
1537 {
1538 int i;
1539
1540 for (i = 0; i < rule->field_count; i++) {
1541 struct audit_field *f = &rule->fields[i];
1542 int result = 0;
1543
1544 switch (f->type) {
1545 case AUDIT_PID:
1546 result = audit_comparator(cb->creds.pid, f->op, f->val);
1547 break;
1548 case AUDIT_UID:
1549 result = audit_comparator(cb->creds.uid, f->op, f->val);
1550 break;
1551 case AUDIT_GID:
1552 result = audit_comparator(cb->creds.gid, f->op, f->val);
1553 break;
1554 case AUDIT_LOGINUID:
1555 result = audit_comparator(cb->loginuid, f->op, f->val);
1556 break;
1557 }
1558
1559 if (!result)
1560 return 0;
1561 }
1562 switch (rule->action) {
1563 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1564 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1565 }
1566 return 1;
1567 }
1568
1569 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1570 {
1571 struct audit_entry *e;
1572 enum audit_state state;
1573 int ret = 1;
1574
1575 rcu_read_lock();
1576 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1577 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1578 if (state == AUDIT_DISABLED)
1579 ret = 0;
1580 break;
1581 }
1582 }
1583 rcu_read_unlock();
1584
1585 return ret; /* Audit by default */
1586 }
1587
1588 int audit_filter_type(int type)
1589 {
1590 struct audit_entry *e;
1591 int result = 0;
1592
1593 rcu_read_lock();
1594 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1595 goto unlock_and_return;
1596
1597 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1598 list) {
1599 int i;
1600 for (i = 0; i < e->rule.field_count; i++) {
1601 struct audit_field *f = &e->rule.fields[i];
1602 if (f->type == AUDIT_MSGTYPE) {
1603 result = audit_comparator(type, f->op, f->val);
1604 if (!result)
1605 break;
1606 }
1607 }
1608 if (result)
1609 goto unlock_and_return;
1610 }
1611 unlock_and_return:
1612 rcu_read_unlock();
1613 return result;
1614 }
1615
1616 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1617 are selinux fields specified in the rule, 0 otherwise. */
1618 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1619 {
1620 int i;
1621
1622 for (i = 0; i < rule->field_count; i++) {
1623 struct audit_field *f = &rule->fields[i];
1624 switch (f->type) {
1625 case AUDIT_SUBJ_USER:
1626 case AUDIT_SUBJ_ROLE:
1627 case AUDIT_SUBJ_TYPE:
1628 case AUDIT_SUBJ_SEN:
1629 case AUDIT_SUBJ_CLR:
1630 case AUDIT_OBJ_USER:
1631 case AUDIT_OBJ_ROLE:
1632 case AUDIT_OBJ_TYPE:
1633 case AUDIT_OBJ_LEV_LOW:
1634 case AUDIT_OBJ_LEV_HIGH:
1635 return 1;
1636 }
1637 }
1638
1639 return 0;
1640 }
1641
1642 /* This function will re-initialize the se_rule field of all applicable rules.
1643 * It will traverse the filter lists serarching for rules that contain selinux
1644 * specific filter fields. When such a rule is found, it is copied, the
1645 * selinux field is re-initialized, and the old rule is replaced with the
1646 * updated rule. */
1647 int selinux_audit_rule_update(void)
1648 {
1649 struct audit_entry *entry, *n, *nentry;
1650 struct audit_watch *watch;
1651 int i, err = 0;
1652
1653 /* audit_filter_mutex synchronizes the writers */
1654 mutex_lock(&audit_filter_mutex);
1655
1656 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1657 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1658 if (!audit_rule_has_selinux(&entry->rule))
1659 continue;
1660
1661 watch = entry->rule.watch;
1662 nentry = audit_dupe_rule(&entry->rule, watch);
1663 if (unlikely(IS_ERR(nentry))) {
1664 /* save the first error encountered for the
1665 * return value */
1666 if (!err)
1667 err = PTR_ERR(nentry);
1668 audit_panic("error updating selinux filters");
1669 if (watch)
1670 list_del(&entry->rule.rlist);
1671 list_del_rcu(&entry->list);
1672 } else {
1673 if (watch) {
1674 list_add(&nentry->rule.rlist,
1675 &watch->rules);
1676 list_del(&entry->rule.rlist);
1677 }
1678 list_replace_rcu(&entry->list, &nentry->list);
1679 }
1680 call_rcu(&entry->rcu, audit_free_rule_rcu);
1681 }
1682 }
1683
1684 mutex_unlock(&audit_filter_mutex);
1685
1686 return err;
1687 }
1688
1689 /* Update watch data in audit rules based on inotify events. */
1690 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1691 u32 cookie, const char *dname, struct inode *inode)
1692 {
1693 struct audit_parent *parent;
1694
1695 parent = container_of(i_watch, struct audit_parent, wdata);
1696
1697 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1698 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1699 inode->i_ino, 0);
1700 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1701 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1702 /* inotify automatically removes the watch and sends IN_IGNORED */
1703 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1704 audit_remove_parent_watches(parent);
1705 /* inotify does not remove the watch, so remove it manually */
1706 else if(mask & IN_MOVE_SELF) {
1707 audit_remove_parent_watches(parent);
1708 inotify_remove_watch_locked(audit_ih, i_watch);
1709 } else if (mask & IN_IGNORED)
1710 put_inotify_watch(i_watch);
1711 }
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