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mm/hotplug: only free wait_table if it's allocated by vmalloc
[linux-2.6/cjktty.git] / kernel / auditfilter.c
blobf9fc54bbe06faa3e845e19871d15ace3e6c5e1b3
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/slab.h>
31 #include <linux/security.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 * LSM 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 /* Audit filter lists, defined in <linux/audit.h> */
48 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
49 LIST_HEAD_INIT(audit_filter_list[0]),
50 LIST_HEAD_INIT(audit_filter_list[1]),
51 LIST_HEAD_INIT(audit_filter_list[2]),
52 LIST_HEAD_INIT(audit_filter_list[3]),
53 LIST_HEAD_INIT(audit_filter_list[4]),
54 LIST_HEAD_INIT(audit_filter_list[5]),
55 #if AUDIT_NR_FILTERS != 6
56 #error Fix audit_filter_list initialiser
57 #endif
58 };
59 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
60 LIST_HEAD_INIT(audit_rules_list[0]),
61 LIST_HEAD_INIT(audit_rules_list[1]),
62 LIST_HEAD_INIT(audit_rules_list[2]),
63 LIST_HEAD_INIT(audit_rules_list[3]),
64 LIST_HEAD_INIT(audit_rules_list[4]),
65 LIST_HEAD_INIT(audit_rules_list[5]),
66 };
67
68 DEFINE_MUTEX(audit_filter_mutex);
69
70 static inline void audit_free_rule(struct audit_entry *e)
71 {
72 int i;
73 struct audit_krule *erule = &e->rule;
74
75 /* some rules don't have associated watches */
76 if (erule->watch)
77 audit_put_watch(erule->watch);
78 if (erule->fields)
79 for (i = 0; i < erule->field_count; i++) {
80 struct audit_field *f = &erule->fields[i];
81 kfree(f->lsm_str);
82 security_audit_rule_free(f->lsm_rule);
83 }
84 kfree(erule->fields);
85 kfree(erule->filterkey);
86 kfree(e);
87 }
88
89 void audit_free_rule_rcu(struct rcu_head *head)
90 {
91 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
92 audit_free_rule(e);
93 }
94
95 /* Initialize an audit filterlist entry. */
96 static inline struct audit_entry *audit_init_entry(u32 field_count)
97 {
98 struct audit_entry *entry;
99 struct audit_field *fields;
100
101 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
102 if (unlikely(!entry))
103 return NULL;
104
105 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
106 if (unlikely(!fields)) {
107 kfree(entry);
108 return NULL;
109 }
110 entry->rule.fields = fields;
111
112 return entry;
113 }
114
115 /* Unpack a filter field's string representation from user-space
116 * buffer. */
117 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
118 {
119 char *str;
120
121 if (!*bufp || (len == 0) || (len > *remain))
122 return ERR_PTR(-EINVAL);
123
124 /* Of the currently implemented string fields, PATH_MAX
125 * defines the longest valid length.
126 */
127 if (len > PATH_MAX)
128 return ERR_PTR(-ENAMETOOLONG);
129
130 str = kmalloc(len + 1, GFP_KERNEL);
131 if (unlikely(!str))
132 return ERR_PTR(-ENOMEM);
133
134 memcpy(str, *bufp, len);
135 str[len] = 0;
136 *bufp += len;
137 *remain -= len;
138
139 return str;
140 }
141
142 /* Translate an inode field to kernel respresentation. */
143 static inline int audit_to_inode(struct audit_krule *krule,
144 struct audit_field *f)
145 {
146 if (krule->listnr != AUDIT_FILTER_EXIT ||
147 krule->watch || krule->inode_f || krule->tree ||
148 (f->op != Audit_equal && f->op != Audit_not_equal))
149 return -EINVAL;
150
151 krule->inode_f = f;
152 return 0;
153 }
154
155 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
156
157 int __init audit_register_class(int class, unsigned *list)
158 {
159 __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
160 if (!p)
161 return -ENOMEM;
162 while (*list != ~0U) {
163 unsigned n = *list++;
164 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
165 kfree(p);
166 return -EINVAL;
167 }
168 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
169 }
170 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
171 kfree(p);
172 return -EINVAL;
173 }
174 classes[class] = p;
175 return 0;
176 }
177
178 int audit_match_class(int class, unsigned syscall)
179 {
180 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
181 return 0;
182 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
183 return 0;
184 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
185 }
186
187 #ifdef CONFIG_AUDITSYSCALL
188 static inline int audit_match_class_bits(int class, u32 *mask)
189 {
190 int i;
191
192 if (classes[class]) {
193 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
194 if (mask[i] & classes[class][i])
195 return 0;
196 }
197 return 1;
198 }
199
200 static int audit_match_signal(struct audit_entry *entry)
201 {
202 struct audit_field *arch = entry->rule.arch_f;
203
204 if (!arch) {
205 /* When arch is unspecified, we must check both masks on biarch
206 * as syscall number alone is ambiguous. */
207 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
208 entry->rule.mask) &&
209 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
210 entry->rule.mask));
211 }
212
213 switch(audit_classify_arch(arch->val)) {
214 case 0: /* native */
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
216 entry->rule.mask));
217 case 1: /* 32bit on biarch */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
219 entry->rule.mask));
220 default:
221 return 1;
222 }
223 }
224 #endif
225
226 /* Common user-space to kernel rule translation. */
227 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
228 {
229 unsigned listnr;
230 struct audit_entry *entry;
231 int i, err;
232
233 err = -EINVAL;
234 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
235 switch(listnr) {
236 default:
237 goto exit_err;
238 #ifdef CONFIG_AUDITSYSCALL
239 case AUDIT_FILTER_ENTRY:
240 if (rule->action == AUDIT_ALWAYS)
241 goto exit_err;
242 case AUDIT_FILTER_EXIT:
243 case AUDIT_FILTER_TASK:
244 #endif
245 case AUDIT_FILTER_USER:
246 case AUDIT_FILTER_TYPE:
247 ;
248 }
249 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
250 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
251 goto exit_err;
252 }
253 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
254 goto exit_err;
255 if (rule->field_count > AUDIT_MAX_FIELDS)
256 goto exit_err;
257
258 err = -ENOMEM;
259 entry = audit_init_entry(rule->field_count);
260 if (!entry)
261 goto exit_err;
262
263 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
264 entry->rule.listnr = listnr;
265 entry->rule.action = rule->action;
266 entry->rule.field_count = rule->field_count;
267
268 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
269 entry->rule.mask[i] = rule->mask[i];
270
271 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
272 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
273 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
274 __u32 *class;
275
276 if (!(*p & AUDIT_BIT(bit)))
277 continue;
278 *p &= ~AUDIT_BIT(bit);
279 class = classes[i];
280 if (class) {
281 int j;
282 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
283 entry->rule.mask[j] |= class[j];
284 }
285 }
286
287 return entry;
288
289 exit_err:
290 return ERR_PTR(err);
291 }
292
293 static u32 audit_ops[] =
294 {
295 [Audit_equal] = AUDIT_EQUAL,
296 [Audit_not_equal] = AUDIT_NOT_EQUAL,
297 [Audit_bitmask] = AUDIT_BIT_MASK,
298 [Audit_bittest] = AUDIT_BIT_TEST,
299 [Audit_lt] = AUDIT_LESS_THAN,
300 [Audit_gt] = AUDIT_GREATER_THAN,
301 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
302 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
303 };
304
305 static u32 audit_to_op(u32 op)
306 {
307 u32 n;
308 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
309 ;
310 return n;
311 }
312
313
314 /* Translate struct audit_rule to kernel's rule respresentation.
315 * Exists for backward compatibility with userspace. */
316 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
317 {
318 struct audit_entry *entry;
319 int err = 0;
320 int i;
321
322 entry = audit_to_entry_common(rule);
323 if (IS_ERR(entry))
324 goto exit_nofree;
325
326 for (i = 0; i < rule->field_count; i++) {
327 struct audit_field *f = &entry->rule.fields[i];
328 u32 n;
329
330 n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
331
332 /* Support for legacy operators where
333 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
334 if (n & AUDIT_NEGATE)
335 f->op = Audit_not_equal;
336 else if (!n)
337 f->op = Audit_equal;
338 else
339 f->op = audit_to_op(n);
340
341 entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1;
342
343 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
344 f->val = rule->values[i];
345 f->uid = INVALID_UID;
346 f->gid = INVALID_GID;
347
348 err = -EINVAL;
349 if (f->op == Audit_bad)
350 goto exit_free;
351
352 switch(f->type) {
353 default:
354 goto exit_free;
355 case AUDIT_UID:
356 case AUDIT_EUID:
357 case AUDIT_SUID:
358 case AUDIT_FSUID:
359 case AUDIT_LOGINUID:
360 /* bit ops not implemented for uid comparisons */
361 if (f->op == Audit_bitmask || f->op == Audit_bittest)
362 goto exit_free;
363
364 f->uid = make_kuid(current_user_ns(), f->val);
365 if (!uid_valid(f->uid))
366 goto exit_free;
367 break;
368 case AUDIT_GID:
369 case AUDIT_EGID:
370 case AUDIT_SGID:
371 case AUDIT_FSGID:
372 /* bit ops not implemented for gid comparisons */
373 if (f->op == Audit_bitmask || f->op == Audit_bittest)
374 goto exit_free;
375
376 f->gid = make_kgid(current_user_ns(), f->val);
377 if (!gid_valid(f->gid))
378 goto exit_free;
379 break;
380 case AUDIT_PID:
381 case AUDIT_PERS:
382 case AUDIT_MSGTYPE:
383 case AUDIT_PPID:
384 case AUDIT_DEVMAJOR:
385 case AUDIT_DEVMINOR:
386 case AUDIT_EXIT:
387 case AUDIT_SUCCESS:
388 /* bit ops are only useful on syscall args */
389 if (f->op == Audit_bitmask || f->op == Audit_bittest)
390 goto exit_free;
391 break;
392 case AUDIT_ARG0:
393 case AUDIT_ARG1:
394 case AUDIT_ARG2:
395 case AUDIT_ARG3:
396 break;
397 /* arch is only allowed to be = or != */
398 case AUDIT_ARCH:
399 if (f->op != Audit_not_equal && f->op != Audit_equal)
400 goto exit_free;
401 entry->rule.arch_f = f;
402 break;
403 case AUDIT_PERM:
404 if (f->val & ~15)
405 goto exit_free;
406 break;
407 case AUDIT_FILETYPE:
408 if (f->val & ~S_IFMT)
409 goto exit_free;
410 break;
411 case AUDIT_INODE:
412 err = audit_to_inode(&entry->rule, f);
413 if (err)
414 goto exit_free;
415 break;
416 }
417 }
418
419 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
420 entry->rule.inode_f = NULL;
421
422 exit_nofree:
423 return entry;
424
425 exit_free:
426 audit_free_rule(entry);
427 return ERR_PTR(err);
428 }
429
430 /* Translate struct audit_rule_data to kernel's rule respresentation. */
431 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
432 size_t datasz)
433 {
434 int err = 0;
435 struct audit_entry *entry;
436 void *bufp;
437 size_t remain = datasz - sizeof(struct audit_rule_data);
438 int i;
439 char *str;
440
441 entry = audit_to_entry_common((struct audit_rule *)data);
442 if (IS_ERR(entry))
443 goto exit_nofree;
444
445 bufp = data->buf;
446 entry->rule.vers_ops = 2;
447 for (i = 0; i < data->field_count; i++) {
448 struct audit_field *f = &entry->rule.fields[i];
449
450 err = -EINVAL;
451
452 f->op = audit_to_op(data->fieldflags[i]);
453 if (f->op == Audit_bad)
454 goto exit_free;
455
456 f->type = data->fields[i];
457 f->val = data->values[i];
458 f->uid = INVALID_UID;
459 f->gid = INVALID_GID;
460 f->lsm_str = NULL;
461 f->lsm_rule = NULL;
462 switch(f->type) {
463 case AUDIT_UID:
464 case AUDIT_EUID:
465 case AUDIT_SUID:
466 case AUDIT_FSUID:
467 case AUDIT_LOGINUID:
468 case AUDIT_OBJ_UID:
469 /* bit ops not implemented for uid comparisons */
470 if (f->op == Audit_bitmask || f->op == Audit_bittest)
471 goto exit_free;
472
473 f->uid = make_kuid(current_user_ns(), f->val);
474 if (!uid_valid(f->uid))
475 goto exit_free;
476 break;
477 case AUDIT_GID:
478 case AUDIT_EGID:
479 case AUDIT_SGID:
480 case AUDIT_FSGID:
481 case AUDIT_OBJ_GID:
482 /* bit ops not implemented for gid comparisons */
483 if (f->op == Audit_bitmask || f->op == Audit_bittest)
484 goto exit_free;
485
486 f->gid = make_kgid(current_user_ns(), f->val);
487 if (!gid_valid(f->gid))
488 goto exit_free;
489 break;
490 case AUDIT_PID:
491 case AUDIT_PERS:
492 case AUDIT_MSGTYPE:
493 case AUDIT_PPID:
494 case AUDIT_DEVMAJOR:
495 case AUDIT_DEVMINOR:
496 case AUDIT_EXIT:
497 case AUDIT_SUCCESS:
498 case AUDIT_ARG0:
499 case AUDIT_ARG1:
500 case AUDIT_ARG2:
501 case AUDIT_ARG3:
502 break;
503 case AUDIT_ARCH:
504 entry->rule.arch_f = f;
505 break;
506 case AUDIT_SUBJ_USER:
507 case AUDIT_SUBJ_ROLE:
508 case AUDIT_SUBJ_TYPE:
509 case AUDIT_SUBJ_SEN:
510 case AUDIT_SUBJ_CLR:
511 case AUDIT_OBJ_USER:
512 case AUDIT_OBJ_ROLE:
513 case AUDIT_OBJ_TYPE:
514 case AUDIT_OBJ_LEV_LOW:
515 case AUDIT_OBJ_LEV_HIGH:
516 str = audit_unpack_string(&bufp, &remain, f->val);
517 if (IS_ERR(str))
518 goto exit_free;
519 entry->rule.buflen += f->val;
520
521 err = security_audit_rule_init(f->type, f->op, str,
522 (void **)&f->lsm_rule);
523 /* Keep currently invalid fields around in case they
524 * become valid after a policy reload. */
525 if (err == -EINVAL) {
526 printk(KERN_WARNING "audit rule for LSM "
527 "\'%s\' is invalid\n", str);
528 err = 0;
529 }
530 if (err) {
531 kfree(str);
532 goto exit_free;
533 } else
534 f->lsm_str = str;
535 break;
536 case AUDIT_WATCH:
537 str = audit_unpack_string(&bufp, &remain, f->val);
538 if (IS_ERR(str))
539 goto exit_free;
540 entry->rule.buflen += f->val;
541
542 err = audit_to_watch(&entry->rule, str, f->val, f->op);
543 if (err) {
544 kfree(str);
545 goto exit_free;
546 }
547 break;
548 case AUDIT_DIR:
549 str = audit_unpack_string(&bufp, &remain, f->val);
550 if (IS_ERR(str))
551 goto exit_free;
552 entry->rule.buflen += f->val;
553
554 err = audit_make_tree(&entry->rule, str, f->op);
555 kfree(str);
556 if (err)
557 goto exit_free;
558 break;
559 case AUDIT_INODE:
560 err = audit_to_inode(&entry->rule, f);
561 if (err)
562 goto exit_free;
563 break;
564 case AUDIT_FILTERKEY:
565 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
566 goto exit_free;
567 str = audit_unpack_string(&bufp, &remain, f->val);
568 if (IS_ERR(str))
569 goto exit_free;
570 entry->rule.buflen += f->val;
571 entry->rule.filterkey = str;
572 break;
573 case AUDIT_PERM:
574 if (f->val & ~15)
575 goto exit_free;
576 break;
577 case AUDIT_FILETYPE:
578 if (f->val & ~S_IFMT)
579 goto exit_free;
580 break;
581 case AUDIT_FIELD_COMPARE:
582 if (f->val > AUDIT_MAX_FIELD_COMPARE)
583 goto exit_free;
584 break;
585 default:
586 goto exit_free;
587 }
588 }
589
590 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
591 entry->rule.inode_f = NULL;
592
593 exit_nofree:
594 return entry;
595
596 exit_free:
597 audit_free_rule(entry);
598 return ERR_PTR(err);
599 }
600
601 /* Pack a filter field's string representation into data block. */
602 static inline size_t audit_pack_string(void **bufp, const char *str)
603 {
604 size_t len = strlen(str);
605
606 memcpy(*bufp, str, len);
607 *bufp += len;
608
609 return len;
610 }
611
612 /* Translate kernel rule respresentation to struct audit_rule.
613 * Exists for backward compatibility with userspace. */
614 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
615 {
616 struct audit_rule *rule;
617 int i;
618
619 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
620 if (unlikely(!rule))
621 return NULL;
622
623 rule->flags = krule->flags | krule->listnr;
624 rule->action = krule->action;
625 rule->field_count = krule->field_count;
626 for (i = 0; i < rule->field_count; i++) {
627 rule->values[i] = krule->fields[i].val;
628 rule->fields[i] = krule->fields[i].type;
629
630 if (krule->vers_ops == 1) {
631 if (krule->fields[i].op == Audit_not_equal)
632 rule->fields[i] |= AUDIT_NEGATE;
633 } else {
634 rule->fields[i] |= audit_ops[krule->fields[i].op];
635 }
636 }
637 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
638
639 return rule;
640 }
641
642 /* Translate kernel rule respresentation to struct audit_rule_data. */
643 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
644 {
645 struct audit_rule_data *data;
646 void *bufp;
647 int i;
648
649 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
650 if (unlikely(!data))
651 return NULL;
652 memset(data, 0, sizeof(*data));
653
654 data->flags = krule->flags | krule->listnr;
655 data->action = krule->action;
656 data->field_count = krule->field_count;
657 bufp = data->buf;
658 for (i = 0; i < data->field_count; i++) {
659 struct audit_field *f = &krule->fields[i];
660
661 data->fields[i] = f->type;
662 data->fieldflags[i] = audit_ops[f->op];
663 switch(f->type) {
664 case AUDIT_SUBJ_USER:
665 case AUDIT_SUBJ_ROLE:
666 case AUDIT_SUBJ_TYPE:
667 case AUDIT_SUBJ_SEN:
668 case AUDIT_SUBJ_CLR:
669 case AUDIT_OBJ_USER:
670 case AUDIT_OBJ_ROLE:
671 case AUDIT_OBJ_TYPE:
672 case AUDIT_OBJ_LEV_LOW:
673 case AUDIT_OBJ_LEV_HIGH:
674 data->buflen += data->values[i] =
675 audit_pack_string(&bufp, f->lsm_str);
676 break;
677 case AUDIT_WATCH:
678 data->buflen += data->values[i] =
679 audit_pack_string(&bufp,
680 audit_watch_path(krule->watch));
681 break;
682 case AUDIT_DIR:
683 data->buflen += data->values[i] =
684 audit_pack_string(&bufp,
685 audit_tree_path(krule->tree));
686 break;
687 case AUDIT_FILTERKEY:
688 data->buflen += data->values[i] =
689 audit_pack_string(&bufp, krule->filterkey);
690 break;
691 default:
692 data->values[i] = f->val;
693 }
694 }
695 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
696
697 return data;
698 }
699
700 /* Compare two rules in kernel format. Considered success if rules
701 * don't match. */
702 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
703 {
704 int i;
705
706 if (a->flags != b->flags ||
707 a->listnr != b->listnr ||
708 a->action != b->action ||
709 a->field_count != b->field_count)
710 return 1;
711
712 for (i = 0; i < a->field_count; i++) {
713 if (a->fields[i].type != b->fields[i].type ||
714 a->fields[i].op != b->fields[i].op)
715 return 1;
716
717 switch(a->fields[i].type) {
718 case AUDIT_SUBJ_USER:
719 case AUDIT_SUBJ_ROLE:
720 case AUDIT_SUBJ_TYPE:
721 case AUDIT_SUBJ_SEN:
722 case AUDIT_SUBJ_CLR:
723 case AUDIT_OBJ_USER:
724 case AUDIT_OBJ_ROLE:
725 case AUDIT_OBJ_TYPE:
726 case AUDIT_OBJ_LEV_LOW:
727 case AUDIT_OBJ_LEV_HIGH:
728 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
729 return 1;
730 break;
731 case AUDIT_WATCH:
732 if (strcmp(audit_watch_path(a->watch),
733 audit_watch_path(b->watch)))
734 return 1;
735 break;
736 case AUDIT_DIR:
737 if (strcmp(audit_tree_path(a->tree),
738 audit_tree_path(b->tree)))
739 return 1;
740 break;
741 case AUDIT_FILTERKEY:
742 /* both filterkeys exist based on above type compare */
743 if (strcmp(a->filterkey, b->filterkey))
744 return 1;
745 break;
746 case AUDIT_UID:
747 case AUDIT_EUID:
748 case AUDIT_SUID:
749 case AUDIT_FSUID:
750 case AUDIT_LOGINUID:
751 case AUDIT_OBJ_UID:
752 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
753 return 1;
754 break;
755 case AUDIT_GID:
756 case AUDIT_EGID:
757 case AUDIT_SGID:
758 case AUDIT_FSGID:
759 case AUDIT_OBJ_GID:
760 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
761 return 1;
762 break;
763 default:
764 if (a->fields[i].val != b->fields[i].val)
765 return 1;
766 }
767 }
768
769 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
770 if (a->mask[i] != b->mask[i])
771 return 1;
772
773 return 0;
774 }
775
776 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
777 * re-initialized. */
778 static inline int audit_dupe_lsm_field(struct audit_field *df,
779 struct audit_field *sf)
780 {
781 int ret = 0;
782 char *lsm_str;
783
784 /* our own copy of lsm_str */
785 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
786 if (unlikely(!lsm_str))
787 return -ENOMEM;
788 df->lsm_str = lsm_str;
789
790 /* our own (refreshed) copy of lsm_rule */
791 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
792 (void **)&df->lsm_rule);
793 /* Keep currently invalid fields around in case they
794 * become valid after a policy reload. */
795 if (ret == -EINVAL) {
796 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
797 "invalid\n", df->lsm_str);
798 ret = 0;
799 }
800
801 return ret;
802 }
803
804 /* Duplicate an audit rule. This will be a deep copy with the exception
805 * of the watch - that pointer is carried over. The LSM specific fields
806 * will be updated in the copy. The point is to be able to replace the old
807 * rule with the new rule in the filterlist, then free the old rule.
808 * The rlist element is undefined; list manipulations are handled apart from
809 * the initial copy. */
810 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
811 {
812 u32 fcount = old->field_count;
813 struct audit_entry *entry;
814 struct audit_krule *new;
815 char *fk;
816 int i, err = 0;
817
818 entry = audit_init_entry(fcount);
819 if (unlikely(!entry))
820 return ERR_PTR(-ENOMEM);
821
822 new = &entry->rule;
823 new->vers_ops = old->vers_ops;
824 new->flags = old->flags;
825 new->listnr = old->listnr;
826 new->action = old->action;
827 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
828 new->mask[i] = old->mask[i];
829 new->prio = old->prio;
830 new->buflen = old->buflen;
831 new->inode_f = old->inode_f;
832 new->field_count = old->field_count;
833
834 /*
835 * note that we are OK with not refcounting here; audit_match_tree()
836 * never dereferences tree and we can't get false positives there
837 * since we'd have to have rule gone from the list *and* removed
838 * before the chunks found by lookup had been allocated, i.e. before
839 * the beginning of list scan.
840 */
841 new->tree = old->tree;
842 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
843
844 /* deep copy this information, updating the lsm_rule fields, because
845 * the originals will all be freed when the old rule is freed. */
846 for (i = 0; i < fcount; i++) {
847 switch (new->fields[i].type) {
848 case AUDIT_SUBJ_USER:
849 case AUDIT_SUBJ_ROLE:
850 case AUDIT_SUBJ_TYPE:
851 case AUDIT_SUBJ_SEN:
852 case AUDIT_SUBJ_CLR:
853 case AUDIT_OBJ_USER:
854 case AUDIT_OBJ_ROLE:
855 case AUDIT_OBJ_TYPE:
856 case AUDIT_OBJ_LEV_LOW:
857 case AUDIT_OBJ_LEV_HIGH:
858 err = audit_dupe_lsm_field(&new->fields[i],
859 &old->fields[i]);
860 break;
861 case AUDIT_FILTERKEY:
862 fk = kstrdup(old->filterkey, GFP_KERNEL);
863 if (unlikely(!fk))
864 err = -ENOMEM;
865 else
866 new->filterkey = fk;
867 }
868 if (err) {
869 audit_free_rule(entry);
870 return ERR_PTR(err);
871 }
872 }
873
874 if (old->watch) {
875 audit_get_watch(old->watch);
876 new->watch = old->watch;
877 }
878
879 return entry;
880 }
881
882 /* Find an existing audit rule.
883 * Caller must hold audit_filter_mutex to prevent stale rule data. */
884 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
885 struct list_head **p)
886 {
887 struct audit_entry *e, *found = NULL;
888 struct list_head *list;
889 int h;
890
891 if (entry->rule.inode_f) {
892 h = audit_hash_ino(entry->rule.inode_f->val);
893 *p = list = &audit_inode_hash[h];
894 } else if (entry->rule.watch) {
895 /* we don't know the inode number, so must walk entire hash */
896 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
897 list = &audit_inode_hash[h];
898 list_for_each_entry(e, list, list)
899 if (!audit_compare_rule(&entry->rule, &e->rule)) {
900 found = e;
901 goto out;
902 }
903 }
904 goto out;
905 } else {
906 *p = list = &audit_filter_list[entry->rule.listnr];
907 }
908
909 list_for_each_entry(e, list, list)
910 if (!audit_compare_rule(&entry->rule, &e->rule)) {
911 found = e;
912 goto out;
913 }
914
915 out:
916 return found;
917 }
918
919 static u64 prio_low = ~0ULL/2;
920 static u64 prio_high = ~0ULL/2 - 1;
921
922 /* Add rule to given filterlist if not a duplicate. */
923 static inline int audit_add_rule(struct audit_entry *entry)
924 {
925 struct audit_entry *e;
926 struct audit_watch *watch = entry->rule.watch;
927 struct audit_tree *tree = entry->rule.tree;
928 struct list_head *list;
929 int err;
930 #ifdef CONFIG_AUDITSYSCALL
931 int dont_count = 0;
932
933 /* If either of these, don't count towards total */
934 if (entry->rule.listnr == AUDIT_FILTER_USER ||
935 entry->rule.listnr == AUDIT_FILTER_TYPE)
936 dont_count = 1;
937 #endif
938
939 mutex_lock(&audit_filter_mutex);
940 e = audit_find_rule(entry, &list);
941 if (e) {
942 mutex_unlock(&audit_filter_mutex);
943 err = -EEXIST;
944 /* normally audit_add_tree_rule() will free it on failure */
945 if (tree)
946 audit_put_tree(tree);
947 goto error;
948 }
949
950 if (watch) {
951 /* audit_filter_mutex is dropped and re-taken during this call */
952 err = audit_add_watch(&entry->rule, &list);
953 if (err) {
954 mutex_unlock(&audit_filter_mutex);
955 goto error;
956 }
957 }
958 if (tree) {
959 err = audit_add_tree_rule(&entry->rule);
960 if (err) {
961 mutex_unlock(&audit_filter_mutex);
962 goto error;
963 }
964 }
965
966 entry->rule.prio = ~0ULL;
967 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
968 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
969 entry->rule.prio = ++prio_high;
970 else
971 entry->rule.prio = --prio_low;
972 }
973
974 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
975 list_add(&entry->rule.list,
976 &audit_rules_list[entry->rule.listnr]);
977 list_add_rcu(&entry->list, list);
978 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
979 } else {
980 list_add_tail(&entry->rule.list,
981 &audit_rules_list[entry->rule.listnr]);
982 list_add_tail_rcu(&entry->list, list);
983 }
984 #ifdef CONFIG_AUDITSYSCALL
985 if (!dont_count)
986 audit_n_rules++;
987
988 if (!audit_match_signal(entry))
989 audit_signals++;
990 #endif
991 mutex_unlock(&audit_filter_mutex);
992
993 return 0;
994
995 error:
996 if (watch)
997 audit_put_watch(watch); /* tmp watch, matches initial get */
998 return err;
999 }
1000
1001 /* Remove an existing rule from filterlist. */
1002 static inline int audit_del_rule(struct audit_entry *entry)
1003 {
1004 struct audit_entry *e;
1005 struct audit_watch *watch = entry->rule.watch;
1006 struct audit_tree *tree = entry->rule.tree;
1007 struct list_head *list;
1008 int ret = 0;
1009 #ifdef CONFIG_AUDITSYSCALL
1010 int dont_count = 0;
1011
1012 /* If either of these, don't count towards total */
1013 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1014 entry->rule.listnr == AUDIT_FILTER_TYPE)
1015 dont_count = 1;
1016 #endif
1017
1018 mutex_lock(&audit_filter_mutex);
1019 e = audit_find_rule(entry, &list);
1020 if (!e) {
1021 mutex_unlock(&audit_filter_mutex);
1022 ret = -ENOENT;
1023 goto out;
1024 }
1025
1026 if (e->rule.watch)
1027 audit_remove_watch_rule(&e->rule);
1028
1029 if (e->rule.tree)
1030 audit_remove_tree_rule(&e->rule);
1031
1032 list_del_rcu(&e->list);
1033 list_del(&e->rule.list);
1034 call_rcu(&e->rcu, audit_free_rule_rcu);
1035
1036 #ifdef CONFIG_AUDITSYSCALL
1037 if (!dont_count)
1038 audit_n_rules--;
1039
1040 if (!audit_match_signal(entry))
1041 audit_signals--;
1042 #endif
1043 mutex_unlock(&audit_filter_mutex);
1044
1045 out:
1046 if (watch)
1047 audit_put_watch(watch); /* match initial get */
1048 if (tree)
1049 audit_put_tree(tree); /* that's the temporary one */
1050
1051 return ret;
1052 }
1053
1054 /* List rules using struct audit_rule. Exists for backward
1055 * compatibility with userspace. */
1056 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1057 {
1058 struct sk_buff *skb;
1059 struct audit_krule *r;
1060 int i;
1061
1062 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1063 * iterator to sync with list writers. */
1064 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1065 list_for_each_entry(r, &audit_rules_list[i], list) {
1066 struct audit_rule *rule;
1067
1068 rule = audit_krule_to_rule(r);
1069 if (unlikely(!rule))
1070 break;
1071 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1072 rule, sizeof(*rule));
1073 if (skb)
1074 skb_queue_tail(q, skb);
1075 kfree(rule);
1076 }
1077 }
1078 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1079 if (skb)
1080 skb_queue_tail(q, skb);
1081 }
1082
1083 /* List rules using struct audit_rule_data. */
1084 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1085 {
1086 struct sk_buff *skb;
1087 struct audit_krule *r;
1088 int i;
1089
1090 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1091 * iterator to sync with list writers. */
1092 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1093 list_for_each_entry(r, &audit_rules_list[i], list) {
1094 struct audit_rule_data *data;
1095
1096 data = audit_krule_to_data(r);
1097 if (unlikely(!data))
1098 break;
1099 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1100 data, sizeof(*data) + data->buflen);
1101 if (skb)
1102 skb_queue_tail(q, skb);
1103 kfree(data);
1104 }
1105 }
1106 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1107 if (skb)
1108 skb_queue_tail(q, skb);
1109 }
1110
1111 /* Log rule additions and removals */
1112 static void audit_log_rule_change(kuid_t loginuid, u32 sessionid, u32 sid,
1113 char *action, struct audit_krule *rule,
1114 int res)
1115 {
1116 struct audit_buffer *ab;
1117
1118 if (!audit_enabled)
1119 return;
1120
1121 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1122 if (!ab)
1123 return;
1124 audit_log_format(ab, "auid=%u ses=%u",
1125 from_kuid(&init_user_ns, loginuid), sessionid);
1126 if (sid) {
1127 char *ctx = NULL;
1128 u32 len;
1129 if (security_secid_to_secctx(sid, &ctx, &len))
1130 audit_log_format(ab, " ssid=%u", sid);
1131 else {
1132 audit_log_format(ab, " subj=%s", ctx);
1133 security_release_secctx(ctx, len);
1134 }
1135 }
1136 audit_log_format(ab, " op=");
1137 audit_log_string(ab, action);
1138 audit_log_key(ab, rule->filterkey);
1139 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1140 audit_log_end(ab);
1141 }
1142
1143 /**
1144 * audit_receive_filter - apply all rules to the specified message type
1145 * @type: audit message type
1146 * @pid: target pid for netlink audit messages
1147 * @seq: netlink audit message sequence (serial) number
1148 * @data: payload data
1149 * @datasz: size of payload data
1150 * @loginuid: loginuid of sender
1151 * @sessionid: sessionid for netlink audit message
1152 * @sid: SE Linux Security ID of sender
1153 */
1154 int audit_receive_filter(int type, int pid, int seq, void *data,
1155 size_t datasz, kuid_t loginuid, u32 sessionid, u32 sid)
1156 {
1157 struct task_struct *tsk;
1158 struct audit_netlink_list *dest;
1159 int err = 0;
1160 struct audit_entry *entry;
1161
1162 switch (type) {
1163 case AUDIT_LIST:
1164 case AUDIT_LIST_RULES:
1165 /* We can't just spew out the rules here because we might fill
1166 * the available socket buffer space and deadlock waiting for
1167 * auditctl to read from it... which isn't ever going to
1168 * happen if we're actually running in the context of auditctl
1169 * trying to _send_ the stuff */
1170
1171 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1172 if (!dest)
1173 return -ENOMEM;
1174 dest->pid = pid;
1175 skb_queue_head_init(&dest->q);
1176
1177 mutex_lock(&audit_filter_mutex);
1178 if (type == AUDIT_LIST)
1179 audit_list(pid, seq, &dest->q);
1180 else
1181 audit_list_rules(pid, seq, &dest->q);
1182 mutex_unlock(&audit_filter_mutex);
1183
1184 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1185 if (IS_ERR(tsk)) {
1186 skb_queue_purge(&dest->q);
1187 kfree(dest);
1188 err = PTR_ERR(tsk);
1189 }
1190 break;
1191 case AUDIT_ADD:
1192 case AUDIT_ADD_RULE:
1193 if (type == AUDIT_ADD)
1194 entry = audit_rule_to_entry(data);
1195 else
1196 entry = audit_data_to_entry(data, datasz);
1197 if (IS_ERR(entry))
1198 return PTR_ERR(entry);
1199
1200 err = audit_add_rule(entry);
1201 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1202 &entry->rule, !err);
1203
1204 if (err)
1205 audit_free_rule(entry);
1206 break;
1207 case AUDIT_DEL:
1208 case AUDIT_DEL_RULE:
1209 if (type == AUDIT_DEL)
1210 entry = audit_rule_to_entry(data);
1211 else
1212 entry = audit_data_to_entry(data, datasz);
1213 if (IS_ERR(entry))
1214 return PTR_ERR(entry);
1215
1216 err = audit_del_rule(entry);
1217 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1218 &entry->rule, !err);
1219
1220 audit_free_rule(entry);
1221 break;
1222 default:
1223 return -EINVAL;
1224 }
1225
1226 return err;
1227 }
1228
1229 int audit_comparator(u32 left, u32 op, u32 right)
1230 {
1231 switch (op) {
1232 case Audit_equal:
1233 return (left == right);
1234 case Audit_not_equal:
1235 return (left != right);
1236 case Audit_lt:
1237 return (left < right);
1238 case Audit_le:
1239 return (left <= right);
1240 case Audit_gt:
1241 return (left > right);
1242 case Audit_ge:
1243 return (left >= right);
1244 case Audit_bitmask:
1245 return (left & right);
1246 case Audit_bittest:
1247 return ((left & right) == right);
1248 default:
1249 BUG();
1250 return 0;
1251 }
1252 }
1253
1254 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1255 {
1256 switch (op) {
1257 case Audit_equal:
1258 return uid_eq(left, right);
1259 case Audit_not_equal:
1260 return !uid_eq(left, right);
1261 case Audit_lt:
1262 return uid_lt(left, right);
1263 case Audit_le:
1264 return uid_lte(left, right);
1265 case Audit_gt:
1266 return uid_gt(left, right);
1267 case Audit_ge:
1268 return uid_gte(left, right);
1269 case Audit_bitmask:
1270 case Audit_bittest:
1271 default:
1272 BUG();
1273 return 0;
1274 }
1275 }
1276
1277 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1278 {
1279 switch (op) {
1280 case Audit_equal:
1281 return gid_eq(left, right);
1282 case Audit_not_equal:
1283 return !gid_eq(left, right);
1284 case Audit_lt:
1285 return gid_lt(left, right);
1286 case Audit_le:
1287 return gid_lte(left, right);
1288 case Audit_gt:
1289 return gid_gt(left, right);
1290 case Audit_ge:
1291 return gid_gte(left, right);
1292 case Audit_bitmask:
1293 case Audit_bittest:
1294 default:
1295 BUG();
1296 return 0;
1297 }
1298 }
1299
1300 /**
1301 * parent_len - find the length of the parent portion of a pathname
1302 * @path: pathname of which to determine length
1303 */
1304 int parent_len(const char *path)
1305 {
1306 int plen;
1307 const char *p;
1308
1309 plen = strlen(path);
1310
1311 if (plen == 0)
1312 return plen;
1313
1314 /* disregard trailing slashes */
1315 p = path + plen - 1;
1316 while ((*p == '/') && (p > path))
1317 p--;
1318
1319 /* walk backward until we find the next slash or hit beginning */
1320 while ((*p != '/') && (p > path))
1321 p--;
1322
1323 /* did we find a slash? Then increment to include it in path */
1324 if (*p == '/')
1325 p++;
1326
1327 return p - path;
1328 }
1329
1330 /**
1331 * audit_compare_dname_path - compare given dentry name with last component in
1332 * given path. Return of 0 indicates a match.
1333 * @dname: dentry name that we're comparing
1334 * @path: full pathname that we're comparing
1335 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1336 * here indicates that we must compute this value.
1337 */
1338 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1339 {
1340 int dlen, pathlen;
1341 const char *p;
1342
1343 dlen = strlen(dname);
1344 pathlen = strlen(path);
1345 if (pathlen < dlen)
1346 return 1;
1347
1348 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1349 if (pathlen - parentlen != dlen)
1350 return 1;
1351
1352 p = path + parentlen;
1353
1354 return strncmp(p, dname, dlen);
1355 }
1356
1357 static int audit_filter_user_rules(struct audit_krule *rule,
1358 enum audit_state *state)
1359 {
1360 int i;
1361
1362 for (i = 0; i < rule->field_count; i++) {
1363 struct audit_field *f = &rule->fields[i];
1364 int result = 0;
1365 u32 sid;
1366
1367 switch (f->type) {
1368 case AUDIT_PID:
1369 result = audit_comparator(task_pid_vnr(current), f->op, f->val);
1370 break;
1371 case AUDIT_UID:
1372 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1373 break;
1374 case AUDIT_GID:
1375 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1376 break;
1377 case AUDIT_LOGINUID:
1378 result = audit_uid_comparator(audit_get_loginuid(current),
1379 f->op, f->uid);
1380 break;
1381 case AUDIT_SUBJ_USER:
1382 case AUDIT_SUBJ_ROLE:
1383 case AUDIT_SUBJ_TYPE:
1384 case AUDIT_SUBJ_SEN:
1385 case AUDIT_SUBJ_CLR:
1386 if (f->lsm_rule) {
1387 security_task_getsecid(current, &sid);
1388 result = security_audit_rule_match(sid,
1389 f->type,
1390 f->op,
1391 f->lsm_rule,
1392 NULL);
1393 }
1394 break;
1395 }
1396
1397 if (!result)
1398 return 0;
1399 }
1400 switch (rule->action) {
1401 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1402 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1403 }
1404 return 1;
1405 }
1406
1407 int audit_filter_user(void)
1408 {
1409 enum audit_state state = AUDIT_DISABLED;
1410 struct audit_entry *e;
1411 int ret = 1;
1412
1413 rcu_read_lock();
1414 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1415 if (audit_filter_user_rules(&e->rule, &state)) {
1416 if (state == AUDIT_DISABLED)
1417 ret = 0;
1418 break;
1419 }
1420 }
1421 rcu_read_unlock();
1422
1423 return ret; /* Audit by default */
1424 }
1425
1426 int audit_filter_type(int type)
1427 {
1428 struct audit_entry *e;
1429 int result = 0;
1430
1431 rcu_read_lock();
1432 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1433 goto unlock_and_return;
1434
1435 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1436 list) {
1437 int i;
1438 for (i = 0; i < e->rule.field_count; i++) {
1439 struct audit_field *f = &e->rule.fields[i];
1440 if (f->type == AUDIT_MSGTYPE) {
1441 result = audit_comparator(type, f->op, f->val);
1442 if (!result)
1443 break;
1444 }
1445 }
1446 if (result)
1447 goto unlock_and_return;
1448 }
1449 unlock_and_return:
1450 rcu_read_unlock();
1451 return result;
1452 }
1453
1454 static int update_lsm_rule(struct audit_krule *r)
1455 {
1456 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1457 struct audit_entry *nentry;
1458 int err = 0;
1459
1460 if (!security_audit_rule_known(r))
1461 return 0;
1462
1463 nentry = audit_dupe_rule(r);
1464 if (IS_ERR(nentry)) {
1465 /* save the first error encountered for the
1466 * return value */
1467 err = PTR_ERR(nentry);
1468 audit_panic("error updating LSM filters");
1469 if (r->watch)
1470 list_del(&r->rlist);
1471 list_del_rcu(&entry->list);
1472 list_del(&r->list);
1473 } else {
1474 if (r->watch || r->tree)
1475 list_replace_init(&r->rlist, &nentry->rule.rlist);
1476 list_replace_rcu(&entry->list, &nentry->list);
1477 list_replace(&r->list, &nentry->rule.list);
1478 }
1479 call_rcu(&entry->rcu, audit_free_rule_rcu);
1480
1481 return err;
1482 }
1483
1484 /* This function will re-initialize the lsm_rule field of all applicable rules.
1485 * It will traverse the filter lists serarching for rules that contain LSM
1486 * specific filter fields. When such a rule is found, it is copied, the
1487 * LSM field is re-initialized, and the old rule is replaced with the
1488 * updated rule. */
1489 int audit_update_lsm_rules(void)
1490 {
1491 struct audit_krule *r, *n;
1492 int i, err = 0;
1493
1494 /* audit_filter_mutex synchronizes the writers */
1495 mutex_lock(&audit_filter_mutex);
1496
1497 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1498 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1499 int res = update_lsm_rule(r);
1500 if (!err)
1501 err = res;
1502 }
1503 }
1504 mutex_unlock(&audit_filter_mutex);
1505
1506 return err;
1507 }
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