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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* auditfilter.c -- filtering of audit events
3 *
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/audit.h>
13#include <linux/kthread.h>
14#include <linux/mutex.h>
15#include <linux/fs.h>
16#include <linux/namei.h>
17#include <linux/netlink.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/security.h>
21#include <net/net_namespace.h>
22#include <net/sock.h>
23#include "audit.h"
24
25/*
26 * Locking model:
27 *
28 * audit_filter_mutex:
29 * Synchronizes writes and blocking reads of audit's filterlist
30 * data. Rcu is used to traverse the filterlist and access
31 * contents of structs audit_entry, audit_watch and opaque
32 * LSM rules during filtering. If modified, these structures
33 * must be copied and replace their counterparts in the filterlist.
34 * An audit_parent struct is not accessed during filtering, so may
35 * be written directly provided audit_filter_mutex is held.
36 */
37
38/* Audit filter lists, defined in <linux/audit.h> */
39struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
40 LIST_HEAD_INIT(audit_filter_list[0]),
41 LIST_HEAD_INIT(audit_filter_list[1]),
42 LIST_HEAD_INIT(audit_filter_list[2]),
43 LIST_HEAD_INIT(audit_filter_list[3]),
44 LIST_HEAD_INIT(audit_filter_list[4]),
45 LIST_HEAD_INIT(audit_filter_list[5]),
46 LIST_HEAD_INIT(audit_filter_list[6]),
47 LIST_HEAD_INIT(audit_filter_list[7]),
48#if AUDIT_NR_FILTERS != 8
49#error Fix audit_filter_list initialiser
50#endif
51};
52static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
53 LIST_HEAD_INIT(audit_rules_list[0]),
54 LIST_HEAD_INIT(audit_rules_list[1]),
55 LIST_HEAD_INIT(audit_rules_list[2]),
56 LIST_HEAD_INIT(audit_rules_list[3]),
57 LIST_HEAD_INIT(audit_rules_list[4]),
58 LIST_HEAD_INIT(audit_rules_list[5]),
59 LIST_HEAD_INIT(audit_rules_list[6]),
60 LIST_HEAD_INIT(audit_rules_list[7]),
61};
62
63DEFINE_MUTEX(audit_filter_mutex);
64
65static void audit_free_lsm_field(struct audit_field *f)
66{
67 switch (f->type) {
68 case AUDIT_SUBJ_USER:
69 case AUDIT_SUBJ_ROLE:
70 case AUDIT_SUBJ_TYPE:
71 case AUDIT_SUBJ_SEN:
72 case AUDIT_SUBJ_CLR:
73 case AUDIT_OBJ_USER:
74 case AUDIT_OBJ_ROLE:
75 case AUDIT_OBJ_TYPE:
76 case AUDIT_OBJ_LEV_LOW:
77 case AUDIT_OBJ_LEV_HIGH:
78 kfree(f->lsm_str);
79 security_audit_rule_free(f->lsm_rule);
80 }
81}
82
83static inline void audit_free_rule(struct audit_entry *e)
84{
85 int i;
86 struct audit_krule *erule = &e->rule;
87
88 /* some rules don't have associated watches */
89 if (erule->watch)
90 audit_put_watch(erule->watch);
91 if (erule->fields)
92 for (i = 0; i < erule->field_count; i++)
93 audit_free_lsm_field(&erule->fields[i]);
94 kfree(erule->fields);
95 kfree(erule->filterkey);
96 kfree(e);
97}
98
99void audit_free_rule_rcu(struct rcu_head *head)
100{
101 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
102 audit_free_rule(e);
103}
104
105/* Initialize an audit filterlist entry. */
106static inline struct audit_entry *audit_init_entry(u32 field_count)
107{
108 struct audit_entry *entry;
109 struct audit_field *fields;
110
111 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
112 if (unlikely(!entry))
113 return NULL;
114
115 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
116 if (unlikely(!fields)) {
117 kfree(entry);
118 return NULL;
119 }
120 entry->rule.fields = fields;
121
122 return entry;
123}
124
125/* Unpack a filter field's string representation from user-space
126 * buffer. */
127char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
128{
129 char *str;
130
131 if (!*bufp || (len == 0) || (len > *remain))
132 return ERR_PTR(-EINVAL);
133
134 /* Of the currently implemented string fields, PATH_MAX
135 * defines the longest valid length.
136 */
137 if (len > PATH_MAX)
138 return ERR_PTR(-ENAMETOOLONG);
139
140 str = kmalloc(len + 1, GFP_KERNEL);
141 if (unlikely(!str))
142 return ERR_PTR(-ENOMEM);
143
144 memcpy(str, *bufp, len);
145 str[len] = 0;
146 *bufp += len;
147 *remain -= len;
148
149 return str;
150}
151
152/* Translate an inode field to kernel representation. */
153static inline int audit_to_inode(struct audit_krule *krule,
154 struct audit_field *f)
155{
156 if ((krule->listnr != AUDIT_FILTER_EXIT &&
157 krule->listnr != AUDIT_FILTER_URING_EXIT) ||
158 krule->inode_f || krule->watch || krule->tree ||
159 (f->op != Audit_equal && f->op != Audit_not_equal))
160 return -EINVAL;
161
162 krule->inode_f = f;
163 return 0;
164}
165
166static __u32 *classes[AUDIT_SYSCALL_CLASSES];
167
168int __init audit_register_class(int class, unsigned *list)
169{
170 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
171 if (!p)
172 return -ENOMEM;
173 while (*list != ~0U) {
174 unsigned n = *list++;
175 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
176 kfree(p);
177 return -EINVAL;
178 }
179 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
180 }
181 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
182 kfree(p);
183 return -EINVAL;
184 }
185 classes[class] = p;
186 return 0;
187}
188
189int audit_match_class(int class, unsigned syscall)
190{
191 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
192 return 0;
193 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
194 return 0;
195 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
196}
197
198#ifdef CONFIG_AUDITSYSCALL
199static inline int audit_match_class_bits(int class, u32 *mask)
200{
201 int i;
202
203 if (classes[class]) {
204 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
205 if (mask[i] & classes[class][i])
206 return 0;
207 }
208 return 1;
209}
210
211static int audit_match_signal(struct audit_entry *entry)
212{
213 struct audit_field *arch = entry->rule.arch_f;
214
215 if (!arch) {
216 /* When arch is unspecified, we must check both masks on biarch
217 * as syscall number alone is ambiguous. */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
219 entry->rule.mask) &&
220 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
221 entry->rule.mask));
222 }
223
224 switch (audit_classify_arch(arch->val)) {
225 case 0: /* native */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
227 entry->rule.mask));
228 case 1: /* 32bit on biarch */
229 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
230 entry->rule.mask));
231 default:
232 return 1;
233 }
234}
235#endif
236
237/* Common user-space to kernel rule translation. */
238static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
239{
240 unsigned listnr;
241 struct audit_entry *entry;
242 int i, err;
243
244 err = -EINVAL;
245 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
246 switch (listnr) {
247 default:
248 goto exit_err;
249#ifdef CONFIG_AUDITSYSCALL
250 case AUDIT_FILTER_ENTRY:
251 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
252 goto exit_err;
253 case AUDIT_FILTER_EXIT:
254 case AUDIT_FILTER_URING_EXIT:
255 case AUDIT_FILTER_TASK:
256#endif
257 case AUDIT_FILTER_USER:
258 case AUDIT_FILTER_EXCLUDE:
259 case AUDIT_FILTER_FS:
260 ;
261 }
262 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
263 pr_err("AUDIT_POSSIBLE is deprecated\n");
264 goto exit_err;
265 }
266 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
267 goto exit_err;
268 if (rule->field_count > AUDIT_MAX_FIELDS)
269 goto exit_err;
270
271 err = -ENOMEM;
272 entry = audit_init_entry(rule->field_count);
273 if (!entry)
274 goto exit_err;
275
276 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
277 entry->rule.listnr = listnr;
278 entry->rule.action = rule->action;
279 entry->rule.field_count = rule->field_count;
280
281 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
282 entry->rule.mask[i] = rule->mask[i];
283
284 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
285 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
286 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
287 __u32 *class;
288
289 if (!(*p & AUDIT_BIT(bit)))
290 continue;
291 *p &= ~AUDIT_BIT(bit);
292 class = classes[i];
293 if (class) {
294 int j;
295 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
296 entry->rule.mask[j] |= class[j];
297 }
298 }
299
300 return entry;
301
302exit_err:
303 return ERR_PTR(err);
304}
305
306static u32 audit_ops[] =
307{
308 [Audit_equal] = AUDIT_EQUAL,
309 [Audit_not_equal] = AUDIT_NOT_EQUAL,
310 [Audit_bitmask] = AUDIT_BIT_MASK,
311 [Audit_bittest] = AUDIT_BIT_TEST,
312 [Audit_lt] = AUDIT_LESS_THAN,
313 [Audit_gt] = AUDIT_GREATER_THAN,
314 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
315 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
316};
317
318static u32 audit_to_op(u32 op)
319{
320 u32 n;
321 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
322 ;
323 return n;
324}
325
326/* check if an audit field is valid */
327static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
328{
329 switch (f->type) {
330 case AUDIT_MSGTYPE:
331 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
332 entry->rule.listnr != AUDIT_FILTER_USER)
333 return -EINVAL;
334 break;
335 case AUDIT_FSTYPE:
336 if (entry->rule.listnr != AUDIT_FILTER_FS)
337 return -EINVAL;
338 break;
339 case AUDIT_PERM:
340 if (entry->rule.listnr == AUDIT_FILTER_URING_EXIT)
341 return -EINVAL;
342 break;
343 }
344
345 switch (entry->rule.listnr) {
346 case AUDIT_FILTER_FS:
347 switch (f->type) {
348 case AUDIT_FSTYPE:
349 case AUDIT_FILTERKEY:
350 break;
351 default:
352 return -EINVAL;
353 }
354 }
355
356 /* Check for valid field type and op */
357 switch (f->type) {
358 case AUDIT_ARG0:
359 case AUDIT_ARG1:
360 case AUDIT_ARG2:
361 case AUDIT_ARG3:
362 case AUDIT_PERS: /* <uapi/linux/personality.h> */
363 case AUDIT_DEVMINOR:
364 /* all ops are valid */
365 break;
366 case AUDIT_UID:
367 case AUDIT_EUID:
368 case AUDIT_SUID:
369 case AUDIT_FSUID:
370 case AUDIT_LOGINUID:
371 case AUDIT_OBJ_UID:
372 case AUDIT_GID:
373 case AUDIT_EGID:
374 case AUDIT_SGID:
375 case AUDIT_FSGID:
376 case AUDIT_OBJ_GID:
377 case AUDIT_PID:
378 case AUDIT_MSGTYPE:
379 case AUDIT_PPID:
380 case AUDIT_DEVMAJOR:
381 case AUDIT_EXIT:
382 case AUDIT_SUCCESS:
383 case AUDIT_INODE:
384 case AUDIT_SESSIONID:
385 case AUDIT_SUBJ_SEN:
386 case AUDIT_SUBJ_CLR:
387 case AUDIT_OBJ_LEV_LOW:
388 case AUDIT_OBJ_LEV_HIGH:
389 case AUDIT_SADDR_FAM:
390 /* bit ops are only useful on syscall args */
391 if (f->op == Audit_bitmask || f->op == Audit_bittest)
392 return -EINVAL;
393 break;
394 case AUDIT_SUBJ_USER:
395 case AUDIT_SUBJ_ROLE:
396 case AUDIT_SUBJ_TYPE:
397 case AUDIT_OBJ_USER:
398 case AUDIT_OBJ_ROLE:
399 case AUDIT_OBJ_TYPE:
400 case AUDIT_WATCH:
401 case AUDIT_DIR:
402 case AUDIT_FILTERKEY:
403 case AUDIT_LOGINUID_SET:
404 case AUDIT_ARCH:
405 case AUDIT_FSTYPE:
406 case AUDIT_PERM:
407 case AUDIT_FILETYPE:
408 case AUDIT_FIELD_COMPARE:
409 case AUDIT_EXE:
410 /* only equal and not equal valid ops */
411 if (f->op != Audit_not_equal && f->op != Audit_equal)
412 return -EINVAL;
413 break;
414 default:
415 /* field not recognized */
416 return -EINVAL;
417 }
418
419 /* Check for select valid field values */
420 switch (f->type) {
421 case AUDIT_LOGINUID_SET:
422 if ((f->val != 0) && (f->val != 1))
423 return -EINVAL;
424 break;
425 case AUDIT_PERM:
426 if (f->val & ~15)
427 return -EINVAL;
428 break;
429 case AUDIT_FILETYPE:
430 if (f->val & ~S_IFMT)
431 return -EINVAL;
432 break;
433 case AUDIT_FIELD_COMPARE:
434 if (f->val > AUDIT_MAX_FIELD_COMPARE)
435 return -EINVAL;
436 break;
437 case AUDIT_SADDR_FAM:
438 if (f->val >= AF_MAX)
439 return -EINVAL;
440 break;
441 default:
442 break;
443 }
444
445 return 0;
446}
447
448/* Translate struct audit_rule_data to kernel's rule representation. */
449static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
450 size_t datasz)
451{
452 int err = 0;
453 struct audit_entry *entry;
454 void *bufp;
455 size_t remain = datasz - sizeof(struct audit_rule_data);
456 int i;
457 char *str;
458 struct audit_fsnotify_mark *audit_mark;
459
460 entry = audit_to_entry_common(data);
461 if (IS_ERR(entry))
462 goto exit_nofree;
463
464 bufp = data->buf;
465 for (i = 0; i < data->field_count; i++) {
466 struct audit_field *f = &entry->rule.fields[i];
467 u32 f_val;
468
469 err = -EINVAL;
470
471 f->op = audit_to_op(data->fieldflags[i]);
472 if (f->op == Audit_bad)
473 goto exit_free;
474
475 f->type = data->fields[i];
476 f_val = data->values[i];
477
478 /* Support legacy tests for a valid loginuid */
479 if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
480 f->type = AUDIT_LOGINUID_SET;
481 f_val = 0;
482 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
483 }
484
485 err = audit_field_valid(entry, f);
486 if (err)
487 goto exit_free;
488
489 err = -EINVAL;
490 switch (f->type) {
491 case AUDIT_LOGINUID:
492 case AUDIT_UID:
493 case AUDIT_EUID:
494 case AUDIT_SUID:
495 case AUDIT_FSUID:
496 case AUDIT_OBJ_UID:
497 f->uid = make_kuid(current_user_ns(), f_val);
498 if (!uid_valid(f->uid))
499 goto exit_free;
500 break;
501 case AUDIT_GID:
502 case AUDIT_EGID:
503 case AUDIT_SGID:
504 case AUDIT_FSGID:
505 case AUDIT_OBJ_GID:
506 f->gid = make_kgid(current_user_ns(), f_val);
507 if (!gid_valid(f->gid))
508 goto exit_free;
509 break;
510 case AUDIT_ARCH:
511 f->val = f_val;
512 entry->rule.arch_f = f;
513 break;
514 case AUDIT_SUBJ_USER:
515 case AUDIT_SUBJ_ROLE:
516 case AUDIT_SUBJ_TYPE:
517 case AUDIT_SUBJ_SEN:
518 case AUDIT_SUBJ_CLR:
519 case AUDIT_OBJ_USER:
520 case AUDIT_OBJ_ROLE:
521 case AUDIT_OBJ_TYPE:
522 case AUDIT_OBJ_LEV_LOW:
523 case AUDIT_OBJ_LEV_HIGH:
524 str = audit_unpack_string(&bufp, &remain, f_val);
525 if (IS_ERR(str)) {
526 err = PTR_ERR(str);
527 goto exit_free;
528 }
529 entry->rule.buflen += f_val;
530 f->lsm_str = str;
531 err = security_audit_rule_init(f->type, f->op, str,
532 (void **)&f->lsm_rule,
533 GFP_KERNEL);
534 /* Keep currently invalid fields around in case they
535 * become valid after a policy reload. */
536 if (err == -EINVAL) {
537 pr_warn("audit rule for LSM \'%s\' is invalid\n",
538 str);
539 err = 0;
540 } else if (err)
541 goto exit_free;
542 break;
543 case AUDIT_WATCH:
544 str = audit_unpack_string(&bufp, &remain, f_val);
545 if (IS_ERR(str)) {
546 err = PTR_ERR(str);
547 goto exit_free;
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 entry->rule.buflen += f_val;
555 break;
556 case AUDIT_DIR:
557 str = audit_unpack_string(&bufp, &remain, f_val);
558 if (IS_ERR(str)) {
559 err = PTR_ERR(str);
560 goto exit_free;
561 }
562 err = audit_make_tree(&entry->rule, str, f->op);
563 kfree(str);
564 if (err)
565 goto exit_free;
566 entry->rule.buflen += f_val;
567 break;
568 case AUDIT_INODE:
569 f->val = f_val;
570 err = audit_to_inode(&entry->rule, f);
571 if (err)
572 goto exit_free;
573 break;
574 case AUDIT_FILTERKEY:
575 if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
576 goto exit_free;
577 str = audit_unpack_string(&bufp, &remain, f_val);
578 if (IS_ERR(str)) {
579 err = PTR_ERR(str);
580 goto exit_free;
581 }
582 entry->rule.buflen += f_val;
583 entry->rule.filterkey = str;
584 break;
585 case AUDIT_EXE:
586 if (entry->rule.exe || f_val > PATH_MAX)
587 goto exit_free;
588 str = audit_unpack_string(&bufp, &remain, f_val);
589 if (IS_ERR(str)) {
590 err = PTR_ERR(str);
591 goto exit_free;
592 }
593 audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
594 if (IS_ERR(audit_mark)) {
595 kfree(str);
596 err = PTR_ERR(audit_mark);
597 goto exit_free;
598 }
599 entry->rule.buflen += f_val;
600 entry->rule.exe = audit_mark;
601 break;
602 default:
603 f->val = f_val;
604 break;
605 }
606 }
607
608 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
609 entry->rule.inode_f = NULL;
610
611exit_nofree:
612 return entry;
613
614exit_free:
615 if (entry->rule.tree)
616 audit_put_tree(entry->rule.tree); /* that's the temporary one */
617 if (entry->rule.exe)
618 audit_remove_mark(entry->rule.exe); /* that's the template one */
619 audit_free_rule(entry);
620 return ERR_PTR(err);
621}
622
623/* Pack a filter field's string representation into data block. */
624static inline size_t audit_pack_string(void **bufp, const char *str)
625{
626 size_t len = strlen(str);
627
628 memcpy(*bufp, str, len);
629 *bufp += len;
630
631 return len;
632}
633
634/* Translate kernel rule representation to struct audit_rule_data. */
635static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
636{
637 struct audit_rule_data *data;
638 void *bufp;
639 int i;
640
641 data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL);
642 if (unlikely(!data))
643 return NULL;
644 memset(data, 0, sizeof(*data));
645
646 data->flags = krule->flags | krule->listnr;
647 data->action = krule->action;
648 data->field_count = krule->field_count;
649 bufp = data->buf;
650 for (i = 0; i < data->field_count; i++) {
651 struct audit_field *f = &krule->fields[i];
652
653 data->fields[i] = f->type;
654 data->fieldflags[i] = audit_ops[f->op];
655 switch (f->type) {
656 case AUDIT_SUBJ_USER:
657 case AUDIT_SUBJ_ROLE:
658 case AUDIT_SUBJ_TYPE:
659 case AUDIT_SUBJ_SEN:
660 case AUDIT_SUBJ_CLR:
661 case AUDIT_OBJ_USER:
662 case AUDIT_OBJ_ROLE:
663 case AUDIT_OBJ_TYPE:
664 case AUDIT_OBJ_LEV_LOW:
665 case AUDIT_OBJ_LEV_HIGH:
666 data->buflen += data->values[i] =
667 audit_pack_string(&bufp, f->lsm_str);
668 break;
669 case AUDIT_WATCH:
670 data->buflen += data->values[i] =
671 audit_pack_string(&bufp,
672 audit_watch_path(krule->watch));
673 break;
674 case AUDIT_DIR:
675 data->buflen += data->values[i] =
676 audit_pack_string(&bufp,
677 audit_tree_path(krule->tree));
678 break;
679 case AUDIT_FILTERKEY:
680 data->buflen += data->values[i] =
681 audit_pack_string(&bufp, krule->filterkey);
682 break;
683 case AUDIT_EXE:
684 data->buflen += data->values[i] =
685 audit_pack_string(&bufp, audit_mark_path(krule->exe));
686 break;
687 case AUDIT_LOGINUID_SET:
688 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
689 data->fields[i] = AUDIT_LOGINUID;
690 data->values[i] = AUDIT_UID_UNSET;
691 break;
692 }
693 fallthrough; /* if set */
694 default:
695 data->values[i] = f->val;
696 }
697 }
698 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
699 data->mask[i] = krule->mask[i];
700
701 return data;
702}
703
704/* Compare two rules in kernel format. Considered success if rules
705 * don't match. */
706static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
707{
708 int i;
709
710 if (a->flags != b->flags ||
711 a->pflags != b->pflags ||
712 a->listnr != b->listnr ||
713 a->action != b->action ||
714 a->field_count != b->field_count)
715 return 1;
716
717 for (i = 0; i < a->field_count; i++) {
718 if (a->fields[i].type != b->fields[i].type ||
719 a->fields[i].op != b->fields[i].op)
720 return 1;
721
722 switch (a->fields[i].type) {
723 case AUDIT_SUBJ_USER:
724 case AUDIT_SUBJ_ROLE:
725 case AUDIT_SUBJ_TYPE:
726 case AUDIT_SUBJ_SEN:
727 case AUDIT_SUBJ_CLR:
728 case AUDIT_OBJ_USER:
729 case AUDIT_OBJ_ROLE:
730 case AUDIT_OBJ_TYPE:
731 case AUDIT_OBJ_LEV_LOW:
732 case AUDIT_OBJ_LEV_HIGH:
733 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
734 return 1;
735 break;
736 case AUDIT_WATCH:
737 if (strcmp(audit_watch_path(a->watch),
738 audit_watch_path(b->watch)))
739 return 1;
740 break;
741 case AUDIT_DIR:
742 if (strcmp(audit_tree_path(a->tree),
743 audit_tree_path(b->tree)))
744 return 1;
745 break;
746 case AUDIT_FILTERKEY:
747 /* both filterkeys exist based on above type compare */
748 if (strcmp(a->filterkey, b->filterkey))
749 return 1;
750 break;
751 case AUDIT_EXE:
752 /* both paths exist based on above type compare */
753 if (strcmp(audit_mark_path(a->exe),
754 audit_mark_path(b->exe)))
755 return 1;
756 break;
757 case AUDIT_UID:
758 case AUDIT_EUID:
759 case AUDIT_SUID:
760 case AUDIT_FSUID:
761 case AUDIT_LOGINUID:
762 case AUDIT_OBJ_UID:
763 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
764 return 1;
765 break;
766 case AUDIT_GID:
767 case AUDIT_EGID:
768 case AUDIT_SGID:
769 case AUDIT_FSGID:
770 case AUDIT_OBJ_GID:
771 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
772 return 1;
773 break;
774 default:
775 if (a->fields[i].val != b->fields[i].val)
776 return 1;
777 }
778 }
779
780 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
781 if (a->mask[i] != b->mask[i])
782 return 1;
783
784 return 0;
785}
786
787/* Duplicate LSM field information. The lsm_rule is opaque, so must be
788 * re-initialized. */
789static inline int audit_dupe_lsm_field(struct audit_field *df,
790 struct audit_field *sf)
791{
792 int ret;
793 char *lsm_str;
794
795 /* our own copy of lsm_str */
796 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
797 if (unlikely(!lsm_str))
798 return -ENOMEM;
799 df->lsm_str = lsm_str;
800
801 /* our own (refreshed) copy of lsm_rule */
802 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
803 (void **)&df->lsm_rule, GFP_KERNEL);
804 /* Keep currently invalid fields around in case they
805 * become valid after a policy reload. */
806 if (ret == -EINVAL) {
807 pr_warn("audit rule for LSM \'%s\' is invalid\n",
808 df->lsm_str);
809 ret = 0;
810 }
811
812 return ret;
813}
814
815/* Duplicate an audit rule. This will be a deep copy with the exception
816 * of the watch - that pointer is carried over. The LSM specific fields
817 * will be updated in the copy. The point is to be able to replace the old
818 * rule with the new rule in the filterlist, then free the old rule.
819 * The rlist element is undefined; list manipulations are handled apart from
820 * the initial copy. */
821struct audit_entry *audit_dupe_rule(struct audit_krule *old)
822{
823 u32 fcount = old->field_count;
824 struct audit_entry *entry;
825 struct audit_krule *new;
826 char *fk;
827 int i, err = 0;
828
829 entry = audit_init_entry(fcount);
830 if (unlikely(!entry))
831 return ERR_PTR(-ENOMEM);
832
833 new = &entry->rule;
834 new->flags = old->flags;
835 new->pflags = old->pflags;
836 new->listnr = old->listnr;
837 new->action = old->action;
838 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
839 new->mask[i] = old->mask[i];
840 new->prio = old->prio;
841 new->buflen = old->buflen;
842 new->inode_f = old->inode_f;
843 new->field_count = old->field_count;
844
845 /*
846 * note that we are OK with not refcounting here; audit_match_tree()
847 * never dereferences tree and we can't get false positives there
848 * since we'd have to have rule gone from the list *and* removed
849 * before the chunks found by lookup had been allocated, i.e. before
850 * the beginning of list scan.
851 */
852 new->tree = old->tree;
853 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
854
855 /* deep copy this information, updating the lsm_rule fields, because
856 * the originals will all be freed when the old rule is freed. */
857 for (i = 0; i < fcount; i++) {
858 switch (new->fields[i].type) {
859 case AUDIT_SUBJ_USER:
860 case AUDIT_SUBJ_ROLE:
861 case AUDIT_SUBJ_TYPE:
862 case AUDIT_SUBJ_SEN:
863 case AUDIT_SUBJ_CLR:
864 case AUDIT_OBJ_USER:
865 case AUDIT_OBJ_ROLE:
866 case AUDIT_OBJ_TYPE:
867 case AUDIT_OBJ_LEV_LOW:
868 case AUDIT_OBJ_LEV_HIGH:
869 err = audit_dupe_lsm_field(&new->fields[i],
870 &old->fields[i]);
871 break;
872 case AUDIT_FILTERKEY:
873 fk = kstrdup(old->filterkey, GFP_KERNEL);
874 if (unlikely(!fk))
875 err = -ENOMEM;
876 else
877 new->filterkey = fk;
878 break;
879 case AUDIT_EXE:
880 err = audit_dupe_exe(new, old);
881 break;
882 }
883 if (err) {
884 if (new->exe)
885 audit_remove_mark(new->exe);
886 audit_free_rule(entry);
887 return ERR_PTR(err);
888 }
889 }
890
891 if (old->watch) {
892 audit_get_watch(old->watch);
893 new->watch = old->watch;
894 }
895
896 return entry;
897}
898
899/* Find an existing audit rule.
900 * Caller must hold audit_filter_mutex to prevent stale rule data. */
901static struct audit_entry *audit_find_rule(struct audit_entry *entry,
902 struct list_head **p)
903{
904 struct audit_entry *e, *found = NULL;
905 struct list_head *list;
906 int h;
907
908 if (entry->rule.inode_f) {
909 h = audit_hash_ino(entry->rule.inode_f->val);
910 *p = list = &audit_inode_hash[h];
911 } else if (entry->rule.watch) {
912 /* we don't know the inode number, so must walk entire hash */
913 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
914 list = &audit_inode_hash[h];
915 list_for_each_entry(e, list, list)
916 if (!audit_compare_rule(&entry->rule, &e->rule)) {
917 found = e;
918 goto out;
919 }
920 }
921 goto out;
922 } else {
923 *p = list = &audit_filter_list[entry->rule.listnr];
924 }
925
926 list_for_each_entry(e, list, list)
927 if (!audit_compare_rule(&entry->rule, &e->rule)) {
928 found = e;
929 goto out;
930 }
931
932out:
933 return found;
934}
935
936static u64 prio_low = ~0ULL/2;
937static u64 prio_high = ~0ULL/2 - 1;
938
939/* Add rule to given filterlist if not a duplicate. */
940static inline int audit_add_rule(struct audit_entry *entry)
941{
942 struct audit_entry *e;
943 struct audit_watch *watch = entry->rule.watch;
944 struct audit_tree *tree = entry->rule.tree;
945 struct list_head *list;
946 int err = 0;
947#ifdef CONFIG_AUDITSYSCALL
948 int dont_count = 0;
949
950 /* If any of these, don't count towards total */
951 switch (entry->rule.listnr) {
952 case AUDIT_FILTER_USER:
953 case AUDIT_FILTER_EXCLUDE:
954 case AUDIT_FILTER_FS:
955 dont_count = 1;
956 }
957#endif
958
959 mutex_lock(&audit_filter_mutex);
960 e = audit_find_rule(entry, &list);
961 if (e) {
962 mutex_unlock(&audit_filter_mutex);
963 err = -EEXIST;
964 /* normally audit_add_tree_rule() will free it on failure */
965 if (tree)
966 audit_put_tree(tree);
967 return err;
968 }
969
970 if (watch) {
971 /* audit_filter_mutex is dropped and re-taken during this call */
972 err = audit_add_watch(&entry->rule, &list);
973 if (err) {
974 mutex_unlock(&audit_filter_mutex);
975 /*
976 * normally audit_add_tree_rule() will free it
977 * on failure
978 */
979 if (tree)
980 audit_put_tree(tree);
981 return err;
982 }
983 }
984 if (tree) {
985 err = audit_add_tree_rule(&entry->rule);
986 if (err) {
987 mutex_unlock(&audit_filter_mutex);
988 return err;
989 }
990 }
991
992 entry->rule.prio = ~0ULL;
993 if (entry->rule.listnr == AUDIT_FILTER_EXIT ||
994 entry->rule.listnr == AUDIT_FILTER_URING_EXIT) {
995 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
996 entry->rule.prio = ++prio_high;
997 else
998 entry->rule.prio = --prio_low;
999 }
1000
1001 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1002 list_add(&entry->rule.list,
1003 &audit_rules_list[entry->rule.listnr]);
1004 list_add_rcu(&entry->list, list);
1005 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1006 } else {
1007 list_add_tail(&entry->rule.list,
1008 &audit_rules_list[entry->rule.listnr]);
1009 list_add_tail_rcu(&entry->list, list);
1010 }
1011#ifdef CONFIG_AUDITSYSCALL
1012 if (!dont_count)
1013 audit_n_rules++;
1014
1015 if (!audit_match_signal(entry))
1016 audit_signals++;
1017#endif
1018 mutex_unlock(&audit_filter_mutex);
1019
1020 return err;
1021}
1022
1023/* Remove an existing rule from filterlist. */
1024int audit_del_rule(struct audit_entry *entry)
1025{
1026 struct audit_entry *e;
1027 struct audit_tree *tree = entry->rule.tree;
1028 struct list_head *list;
1029 int ret = 0;
1030#ifdef CONFIG_AUDITSYSCALL
1031 int dont_count = 0;
1032
1033 /* If any of these, don't count towards total */
1034 switch (entry->rule.listnr) {
1035 case AUDIT_FILTER_USER:
1036 case AUDIT_FILTER_EXCLUDE:
1037 case AUDIT_FILTER_FS:
1038 dont_count = 1;
1039 }
1040#endif
1041
1042 mutex_lock(&audit_filter_mutex);
1043 e = audit_find_rule(entry, &list);
1044 if (!e) {
1045 ret = -ENOENT;
1046 goto out;
1047 }
1048
1049 if (e->rule.watch)
1050 audit_remove_watch_rule(&e->rule);
1051
1052 if (e->rule.tree)
1053 audit_remove_tree_rule(&e->rule);
1054
1055 if (e->rule.exe)
1056 audit_remove_mark_rule(&e->rule);
1057
1058#ifdef CONFIG_AUDITSYSCALL
1059 if (!dont_count)
1060 audit_n_rules--;
1061
1062 if (!audit_match_signal(entry))
1063 audit_signals--;
1064#endif
1065
1066 list_del_rcu(&e->list);
1067 list_del(&e->rule.list);
1068 call_rcu(&e->rcu, audit_free_rule_rcu);
1069
1070out:
1071 mutex_unlock(&audit_filter_mutex);
1072
1073 if (tree)
1074 audit_put_tree(tree); /* that's the temporary one */
1075
1076 return ret;
1077}
1078
1079/* List rules using struct audit_rule_data. */
1080static void audit_list_rules(int seq, struct sk_buff_head *q)
1081{
1082 struct sk_buff *skb;
1083 struct audit_krule *r;
1084 int i;
1085
1086 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1087 * iterator to sync with list writers. */
1088 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1089 list_for_each_entry(r, &audit_rules_list[i], list) {
1090 struct audit_rule_data *data;
1091
1092 data = audit_krule_to_data(r);
1093 if (unlikely(!data))
1094 break;
1095 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1096 data,
1097 struct_size(data, buf, data->buflen));
1098 if (skb)
1099 skb_queue_tail(q, skb);
1100 kfree(data);
1101 }
1102 }
1103 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1104 if (skb)
1105 skb_queue_tail(q, skb);
1106}
1107
1108/* Log rule additions and removals */
1109static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1110{
1111 struct audit_buffer *ab;
1112
1113 if (!audit_enabled)
1114 return;
1115
1116 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1117 if (!ab)
1118 return;
1119 audit_log_session_info(ab);
1120 audit_log_task_context(ab);
1121 audit_log_format(ab, " op=%s", action);
1122 audit_log_key(ab, rule->filterkey);
1123 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1124 audit_log_end(ab);
1125}
1126
1127/**
1128 * audit_rule_change - apply all rules to the specified message type
1129 * @type: audit message type
1130 * @seq: netlink audit message sequence (serial) number
1131 * @data: payload data
1132 * @datasz: size of payload data
1133 */
1134int audit_rule_change(int type, int seq, void *data, size_t datasz)
1135{
1136 int err = 0;
1137 struct audit_entry *entry;
1138
1139 switch (type) {
1140 case AUDIT_ADD_RULE:
1141 entry = audit_data_to_entry(data, datasz);
1142 if (IS_ERR(entry))
1143 return PTR_ERR(entry);
1144 err = audit_add_rule(entry);
1145 audit_log_rule_change("add_rule", &entry->rule, !err);
1146 break;
1147 case AUDIT_DEL_RULE:
1148 entry = audit_data_to_entry(data, datasz);
1149 if (IS_ERR(entry))
1150 return PTR_ERR(entry);
1151 err = audit_del_rule(entry);
1152 audit_log_rule_change("remove_rule", &entry->rule, !err);
1153 break;
1154 default:
1155 WARN_ON(1);
1156 return -EINVAL;
1157 }
1158
1159 if (err || type == AUDIT_DEL_RULE) {
1160 if (entry->rule.exe)
1161 audit_remove_mark(entry->rule.exe);
1162 audit_free_rule(entry);
1163 }
1164
1165 return err;
1166}
1167
1168/**
1169 * audit_list_rules_send - list the audit rules
1170 * @request_skb: skb of request we are replying to (used to target the reply)
1171 * @seq: netlink audit message sequence (serial) number
1172 */
1173int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1174{
1175 struct task_struct *tsk;
1176 struct audit_netlink_list *dest;
1177
1178 /* We can't just spew out the rules here because we might fill
1179 * the available socket buffer space and deadlock waiting for
1180 * auditctl to read from it... which isn't ever going to
1181 * happen if we're actually running in the context of auditctl
1182 * trying to _send_ the stuff */
1183
1184 dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1185 if (!dest)
1186 return -ENOMEM;
1187 dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1188 dest->portid = NETLINK_CB(request_skb).portid;
1189 skb_queue_head_init(&dest->q);
1190
1191 mutex_lock(&audit_filter_mutex);
1192 audit_list_rules(seq, &dest->q);
1193 mutex_unlock(&audit_filter_mutex);
1194
1195 tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1196 if (IS_ERR(tsk)) {
1197 skb_queue_purge(&dest->q);
1198 put_net(dest->net);
1199 kfree(dest);
1200 return PTR_ERR(tsk);
1201 }
1202
1203 return 0;
1204}
1205
1206int audit_comparator(u32 left, u32 op, u32 right)
1207{
1208 switch (op) {
1209 case Audit_equal:
1210 return (left == right);
1211 case Audit_not_equal:
1212 return (left != right);
1213 case Audit_lt:
1214 return (left < right);
1215 case Audit_le:
1216 return (left <= right);
1217 case Audit_gt:
1218 return (left > right);
1219 case Audit_ge:
1220 return (left >= right);
1221 case Audit_bitmask:
1222 return (left & right);
1223 case Audit_bittest:
1224 return ((left & right) == right);
1225 default:
1226 return 0;
1227 }
1228}
1229
1230int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1231{
1232 switch (op) {
1233 case Audit_equal:
1234 return uid_eq(left, right);
1235 case Audit_not_equal:
1236 return !uid_eq(left, right);
1237 case Audit_lt:
1238 return uid_lt(left, right);
1239 case Audit_le:
1240 return uid_lte(left, right);
1241 case Audit_gt:
1242 return uid_gt(left, right);
1243 case Audit_ge:
1244 return uid_gte(left, right);
1245 case Audit_bitmask:
1246 case Audit_bittest:
1247 default:
1248 return 0;
1249 }
1250}
1251
1252int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1253{
1254 switch (op) {
1255 case Audit_equal:
1256 return gid_eq(left, right);
1257 case Audit_not_equal:
1258 return !gid_eq(left, right);
1259 case Audit_lt:
1260 return gid_lt(left, right);
1261 case Audit_le:
1262 return gid_lte(left, right);
1263 case Audit_gt:
1264 return gid_gt(left, right);
1265 case Audit_ge:
1266 return gid_gte(left, right);
1267 case Audit_bitmask:
1268 case Audit_bittest:
1269 default:
1270 return 0;
1271 }
1272}
1273
1274/**
1275 * parent_len - find the length of the parent portion of a pathname
1276 * @path: pathname of which to determine length
1277 */
1278int parent_len(const char *path)
1279{
1280 int plen;
1281 const char *p;
1282
1283 plen = strlen(path);
1284
1285 if (plen == 0)
1286 return plen;
1287
1288 /* disregard trailing slashes */
1289 p = path + plen - 1;
1290 while ((*p == '/') && (p > path))
1291 p--;
1292
1293 /* walk backward until we find the next slash or hit beginning */
1294 while ((*p != '/') && (p > path))
1295 p--;
1296
1297 /* did we find a slash? Then increment to include it in path */
1298 if (*p == '/')
1299 p++;
1300
1301 return p - path;
1302}
1303
1304/**
1305 * audit_compare_dname_path - compare given dentry name with last component in
1306 * given path. Return of 0 indicates a match.
1307 * @dname: dentry name that we're comparing
1308 * @path: full pathname that we're comparing
1309 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1310 * here indicates that we must compute this value.
1311 */
1312int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1313{
1314 int dlen, pathlen;
1315 const char *p;
1316
1317 dlen = dname->len;
1318 pathlen = strlen(path);
1319 if (pathlen < dlen)
1320 return 1;
1321
1322 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1323 if (pathlen - parentlen != dlen)
1324 return 1;
1325
1326 p = path + parentlen;
1327
1328 return strncmp(p, dname->name, dlen);
1329}
1330
1331int audit_filter(int msgtype, unsigned int listtype)
1332{
1333 struct audit_entry *e;
1334 int ret = 1; /* Audit by default */
1335
1336 rcu_read_lock();
1337 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1338 int i, result = 0;
1339
1340 for (i = 0; i < e->rule.field_count; i++) {
1341 struct audit_field *f = &e->rule.fields[i];
1342 struct lsm_prop prop = { };
1343 pid_t pid;
1344
1345 switch (f->type) {
1346 case AUDIT_PID:
1347 pid = task_tgid_nr(current);
1348 result = audit_comparator(pid, f->op, f->val);
1349 break;
1350 case AUDIT_UID:
1351 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1352 break;
1353 case AUDIT_GID:
1354 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1355 break;
1356 case AUDIT_LOGINUID:
1357 result = audit_uid_comparator(audit_get_loginuid(current),
1358 f->op, f->uid);
1359 break;
1360 case AUDIT_LOGINUID_SET:
1361 result = audit_comparator(audit_loginuid_set(current),
1362 f->op, f->val);
1363 break;
1364 case AUDIT_MSGTYPE:
1365 result = audit_comparator(msgtype, f->op, f->val);
1366 break;
1367 case AUDIT_SUBJ_USER:
1368 case AUDIT_SUBJ_ROLE:
1369 case AUDIT_SUBJ_TYPE:
1370 case AUDIT_SUBJ_SEN:
1371 case AUDIT_SUBJ_CLR:
1372 if (f->lsm_rule) {
1373 security_current_getlsmprop_subj(&prop);
1374 result = security_audit_rule_match(
1375 &prop, f->type, f->op,
1376 f->lsm_rule);
1377 }
1378 break;
1379 case AUDIT_EXE:
1380 result = audit_exe_compare(current, e->rule.exe);
1381 if (f->op == Audit_not_equal)
1382 result = !result;
1383 break;
1384 default:
1385 goto unlock_and_return;
1386 }
1387 if (result < 0) /* error */
1388 goto unlock_and_return;
1389 if (!result)
1390 break;
1391 }
1392 if (result > 0) {
1393 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1394 ret = 0;
1395 break;
1396 }
1397 }
1398unlock_and_return:
1399 rcu_read_unlock();
1400 return ret;
1401}
1402
1403static int update_lsm_rule(struct audit_krule *r)
1404{
1405 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1406 struct audit_entry *nentry;
1407 int err = 0;
1408
1409 if (!security_audit_rule_known(r))
1410 return 0;
1411
1412 nentry = audit_dupe_rule(r);
1413 if (entry->rule.exe)
1414 audit_remove_mark(entry->rule.exe);
1415 if (IS_ERR(nentry)) {
1416 /* save the first error encountered for the
1417 * return value */
1418 err = PTR_ERR(nentry);
1419 audit_panic("error updating LSM filters");
1420 if (r->watch)
1421 list_del(&r->rlist);
1422 list_del_rcu(&entry->list);
1423 list_del(&r->list);
1424 } else {
1425 if (r->watch || r->tree)
1426 list_replace_init(&r->rlist, &nentry->rule.rlist);
1427 list_replace_rcu(&entry->list, &nentry->list);
1428 list_replace(&r->list, &nentry->rule.list);
1429 }
1430 call_rcu(&entry->rcu, audit_free_rule_rcu);
1431
1432 return err;
1433}
1434
1435/* This function will re-initialize the lsm_rule field of all applicable rules.
1436 * It will traverse the filter lists serarching for rules that contain LSM
1437 * specific filter fields. When such a rule is found, it is copied, the
1438 * LSM field is re-initialized, and the old rule is replaced with the
1439 * updated rule. */
1440int audit_update_lsm_rules(void)
1441{
1442 struct audit_krule *r, *n;
1443 int i, err = 0;
1444
1445 /* audit_filter_mutex synchronizes the writers */
1446 mutex_lock(&audit_filter_mutex);
1447
1448 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1449 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1450 int res = update_lsm_rule(r);
1451 if (!err)
1452 err = res;
1453 }
1454 }
1455 mutex_unlock(&audit_filter_mutex);
1456
1457 return err;
1458}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* auditfilter.c -- filtering of audit events
3 *
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/audit.h>
13#include <linux/kthread.h>
14#include <linux/mutex.h>
15#include <linux/fs.h>
16#include <linux/namei.h>
17#include <linux/netlink.h>
18#include <linux/sched.h>
19#include <linux/slab.h>
20#include <linux/security.h>
21#include <net/net_namespace.h>
22#include <net/sock.h>
23#include "audit.h"
24
25/*
26 * Locking model:
27 *
28 * audit_filter_mutex:
29 * Synchronizes writes and blocking reads of audit's filterlist
30 * data. Rcu is used to traverse the filterlist and access
31 * contents of structs audit_entry, audit_watch and opaque
32 * LSM rules during filtering. If modified, these structures
33 * must be copied and replace their counterparts in the filterlist.
34 * An audit_parent struct is not accessed during filtering, so may
35 * be written directly provided audit_filter_mutex is held.
36 */
37
38/* Audit filter lists, defined in <linux/audit.h> */
39struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
40 LIST_HEAD_INIT(audit_filter_list[0]),
41 LIST_HEAD_INIT(audit_filter_list[1]),
42 LIST_HEAD_INIT(audit_filter_list[2]),
43 LIST_HEAD_INIT(audit_filter_list[3]),
44 LIST_HEAD_INIT(audit_filter_list[4]),
45 LIST_HEAD_INIT(audit_filter_list[5]),
46 LIST_HEAD_INIT(audit_filter_list[6]),
47#if AUDIT_NR_FILTERS != 7
48#error Fix audit_filter_list initialiser
49#endif
50};
51static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
52 LIST_HEAD_INIT(audit_rules_list[0]),
53 LIST_HEAD_INIT(audit_rules_list[1]),
54 LIST_HEAD_INIT(audit_rules_list[2]),
55 LIST_HEAD_INIT(audit_rules_list[3]),
56 LIST_HEAD_INIT(audit_rules_list[4]),
57 LIST_HEAD_INIT(audit_rules_list[5]),
58 LIST_HEAD_INIT(audit_rules_list[6]),
59};
60
61DEFINE_MUTEX(audit_filter_mutex);
62
63static void audit_free_lsm_field(struct audit_field *f)
64{
65 switch (f->type) {
66 case AUDIT_SUBJ_USER:
67 case AUDIT_SUBJ_ROLE:
68 case AUDIT_SUBJ_TYPE:
69 case AUDIT_SUBJ_SEN:
70 case AUDIT_SUBJ_CLR:
71 case AUDIT_OBJ_USER:
72 case AUDIT_OBJ_ROLE:
73 case AUDIT_OBJ_TYPE:
74 case AUDIT_OBJ_LEV_LOW:
75 case AUDIT_OBJ_LEV_HIGH:
76 kfree(f->lsm_str);
77 security_audit_rule_free(f->lsm_rule);
78 }
79}
80
81static inline void audit_free_rule(struct audit_entry *e)
82{
83 int i;
84 struct audit_krule *erule = &e->rule;
85
86 /* some rules don't have associated watches */
87 if (erule->watch)
88 audit_put_watch(erule->watch);
89 if (erule->fields)
90 for (i = 0; i < erule->field_count; i++)
91 audit_free_lsm_field(&erule->fields[i]);
92 kfree(erule->fields);
93 kfree(erule->filterkey);
94 kfree(e);
95}
96
97void audit_free_rule_rcu(struct rcu_head *head)
98{
99 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
100 audit_free_rule(e);
101}
102
103/* Initialize an audit filterlist entry. */
104static inline struct audit_entry *audit_init_entry(u32 field_count)
105{
106 struct audit_entry *entry;
107 struct audit_field *fields;
108
109 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
110 if (unlikely(!entry))
111 return NULL;
112
113 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
114 if (unlikely(!fields)) {
115 kfree(entry);
116 return NULL;
117 }
118 entry->rule.fields = fields;
119
120 return entry;
121}
122
123/* Unpack a filter field's string representation from user-space
124 * buffer. */
125char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
126{
127 char *str;
128
129 if (!*bufp || (len == 0) || (len > *remain))
130 return ERR_PTR(-EINVAL);
131
132 /* Of the currently implemented string fields, PATH_MAX
133 * defines the longest valid length.
134 */
135 if (len > PATH_MAX)
136 return ERR_PTR(-ENAMETOOLONG);
137
138 str = kmalloc(len + 1, GFP_KERNEL);
139 if (unlikely(!str))
140 return ERR_PTR(-ENOMEM);
141
142 memcpy(str, *bufp, len);
143 str[len] = 0;
144 *bufp += len;
145 *remain -= len;
146
147 return str;
148}
149
150/* Translate an inode field to kernel representation. */
151static inline int audit_to_inode(struct audit_krule *krule,
152 struct audit_field *f)
153{
154 if (krule->listnr != AUDIT_FILTER_EXIT ||
155 krule->inode_f || krule->watch || krule->tree ||
156 (f->op != Audit_equal && f->op != Audit_not_equal))
157 return -EINVAL;
158
159 krule->inode_f = f;
160 return 0;
161}
162
163static __u32 *classes[AUDIT_SYSCALL_CLASSES];
164
165int __init audit_register_class(int class, unsigned *list)
166{
167 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
168 if (!p)
169 return -ENOMEM;
170 while (*list != ~0U) {
171 unsigned n = *list++;
172 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
173 kfree(p);
174 return -EINVAL;
175 }
176 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
177 }
178 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
179 kfree(p);
180 return -EINVAL;
181 }
182 classes[class] = p;
183 return 0;
184}
185
186int audit_match_class(int class, unsigned syscall)
187{
188 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
189 return 0;
190 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
191 return 0;
192 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
193}
194
195#ifdef CONFIG_AUDITSYSCALL
196static inline int audit_match_class_bits(int class, u32 *mask)
197{
198 int i;
199
200 if (classes[class]) {
201 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
202 if (mask[i] & classes[class][i])
203 return 0;
204 }
205 return 1;
206}
207
208static int audit_match_signal(struct audit_entry *entry)
209{
210 struct audit_field *arch = entry->rule.arch_f;
211
212 if (!arch) {
213 /* When arch is unspecified, we must check both masks on biarch
214 * as syscall number alone is ambiguous. */
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
216 entry->rule.mask) &&
217 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
218 entry->rule.mask));
219 }
220
221 switch(audit_classify_arch(arch->val)) {
222 case 0: /* native */
223 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
224 entry->rule.mask));
225 case 1: /* 32bit on biarch */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
227 entry->rule.mask));
228 default:
229 return 1;
230 }
231}
232#endif
233
234/* Common user-space to kernel rule translation. */
235static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
236{
237 unsigned listnr;
238 struct audit_entry *entry;
239 int i, err;
240
241 err = -EINVAL;
242 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
243 switch(listnr) {
244 default:
245 goto exit_err;
246#ifdef CONFIG_AUDITSYSCALL
247 case AUDIT_FILTER_ENTRY:
248 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
249 goto exit_err;
250 case AUDIT_FILTER_EXIT:
251 case AUDIT_FILTER_TASK:
252#endif
253 case AUDIT_FILTER_USER:
254 case AUDIT_FILTER_EXCLUDE:
255 case AUDIT_FILTER_FS:
256 ;
257 }
258 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
259 pr_err("AUDIT_POSSIBLE is deprecated\n");
260 goto exit_err;
261 }
262 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
263 goto exit_err;
264 if (rule->field_count > AUDIT_MAX_FIELDS)
265 goto exit_err;
266
267 err = -ENOMEM;
268 entry = audit_init_entry(rule->field_count);
269 if (!entry)
270 goto exit_err;
271
272 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
273 entry->rule.listnr = listnr;
274 entry->rule.action = rule->action;
275 entry->rule.field_count = rule->field_count;
276
277 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
278 entry->rule.mask[i] = rule->mask[i];
279
280 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
281 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
282 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
283 __u32 *class;
284
285 if (!(*p & AUDIT_BIT(bit)))
286 continue;
287 *p &= ~AUDIT_BIT(bit);
288 class = classes[i];
289 if (class) {
290 int j;
291 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
292 entry->rule.mask[j] |= class[j];
293 }
294 }
295
296 return entry;
297
298exit_err:
299 return ERR_PTR(err);
300}
301
302static u32 audit_ops[] =
303{
304 [Audit_equal] = AUDIT_EQUAL,
305 [Audit_not_equal] = AUDIT_NOT_EQUAL,
306 [Audit_bitmask] = AUDIT_BIT_MASK,
307 [Audit_bittest] = AUDIT_BIT_TEST,
308 [Audit_lt] = AUDIT_LESS_THAN,
309 [Audit_gt] = AUDIT_GREATER_THAN,
310 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
311 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
312};
313
314static u32 audit_to_op(u32 op)
315{
316 u32 n;
317 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
318 ;
319 return n;
320}
321
322/* check if an audit field is valid */
323static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
324{
325 switch (f->type) {
326 case AUDIT_MSGTYPE:
327 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
328 entry->rule.listnr != AUDIT_FILTER_USER)
329 return -EINVAL;
330 break;
331 case AUDIT_FSTYPE:
332 if (entry->rule.listnr != AUDIT_FILTER_FS)
333 return -EINVAL;
334 break;
335 }
336
337 switch (entry->rule.listnr) {
338 case AUDIT_FILTER_FS:
339 switch(f->type) {
340 case AUDIT_FSTYPE:
341 case AUDIT_FILTERKEY:
342 break;
343 default:
344 return -EINVAL;
345 }
346 }
347
348 /* Check for valid field type and op */
349 switch (f->type) {
350 case AUDIT_ARG0:
351 case AUDIT_ARG1:
352 case AUDIT_ARG2:
353 case AUDIT_ARG3:
354 case AUDIT_PERS: /* <uapi/linux/personality.h> */
355 case AUDIT_DEVMINOR:
356 /* all ops are valid */
357 break;
358 case AUDIT_UID:
359 case AUDIT_EUID:
360 case AUDIT_SUID:
361 case AUDIT_FSUID:
362 case AUDIT_LOGINUID:
363 case AUDIT_OBJ_UID:
364 case AUDIT_GID:
365 case AUDIT_EGID:
366 case AUDIT_SGID:
367 case AUDIT_FSGID:
368 case AUDIT_OBJ_GID:
369 case AUDIT_PID:
370 case AUDIT_MSGTYPE:
371 case AUDIT_PPID:
372 case AUDIT_DEVMAJOR:
373 case AUDIT_EXIT:
374 case AUDIT_SUCCESS:
375 case AUDIT_INODE:
376 case AUDIT_SESSIONID:
377 case AUDIT_SUBJ_SEN:
378 case AUDIT_SUBJ_CLR:
379 case AUDIT_OBJ_LEV_LOW:
380 case AUDIT_OBJ_LEV_HIGH:
381 case AUDIT_SADDR_FAM:
382 /* bit ops are only useful on syscall args */
383 if (f->op == Audit_bitmask || f->op == Audit_bittest)
384 return -EINVAL;
385 break;
386 case AUDIT_SUBJ_USER:
387 case AUDIT_SUBJ_ROLE:
388 case AUDIT_SUBJ_TYPE:
389 case AUDIT_OBJ_USER:
390 case AUDIT_OBJ_ROLE:
391 case AUDIT_OBJ_TYPE:
392 case AUDIT_WATCH:
393 case AUDIT_DIR:
394 case AUDIT_FILTERKEY:
395 case AUDIT_LOGINUID_SET:
396 case AUDIT_ARCH:
397 case AUDIT_FSTYPE:
398 case AUDIT_PERM:
399 case AUDIT_FILETYPE:
400 case AUDIT_FIELD_COMPARE:
401 case AUDIT_EXE:
402 /* only equal and not equal valid ops */
403 if (f->op != Audit_not_equal && f->op != Audit_equal)
404 return -EINVAL;
405 break;
406 default:
407 /* field not recognized */
408 return -EINVAL;
409 }
410
411 /* Check for select valid field values */
412 switch (f->type) {
413 case AUDIT_LOGINUID_SET:
414 if ((f->val != 0) && (f->val != 1))
415 return -EINVAL;
416 break;
417 case AUDIT_PERM:
418 if (f->val & ~15)
419 return -EINVAL;
420 break;
421 case AUDIT_FILETYPE:
422 if (f->val & ~S_IFMT)
423 return -EINVAL;
424 break;
425 case AUDIT_FIELD_COMPARE:
426 if (f->val > AUDIT_MAX_FIELD_COMPARE)
427 return -EINVAL;
428 break;
429 case AUDIT_SADDR_FAM:
430 if (f->val >= AF_MAX)
431 return -EINVAL;
432 break;
433 default:
434 break;
435 }
436
437 return 0;
438}
439
440/* Translate struct audit_rule_data to kernel's rule representation. */
441static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
442 size_t datasz)
443{
444 int err = 0;
445 struct audit_entry *entry;
446 void *bufp;
447 size_t remain = datasz - sizeof(struct audit_rule_data);
448 int i;
449 char *str;
450 struct audit_fsnotify_mark *audit_mark;
451
452 entry = audit_to_entry_common(data);
453 if (IS_ERR(entry))
454 goto exit_nofree;
455
456 bufp = data->buf;
457 for (i = 0; i < data->field_count; i++) {
458 struct audit_field *f = &entry->rule.fields[i];
459 u32 f_val;
460
461 err = -EINVAL;
462
463 f->op = audit_to_op(data->fieldflags[i]);
464 if (f->op == Audit_bad)
465 goto exit_free;
466
467 f->type = data->fields[i];
468 f_val = data->values[i];
469
470 /* Support legacy tests for a valid loginuid */
471 if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
472 f->type = AUDIT_LOGINUID_SET;
473 f_val = 0;
474 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
475 }
476
477 err = audit_field_valid(entry, f);
478 if (err)
479 goto exit_free;
480
481 err = -EINVAL;
482 switch (f->type) {
483 case AUDIT_LOGINUID:
484 case AUDIT_UID:
485 case AUDIT_EUID:
486 case AUDIT_SUID:
487 case AUDIT_FSUID:
488 case AUDIT_OBJ_UID:
489 f->uid = make_kuid(current_user_ns(), f_val);
490 if (!uid_valid(f->uid))
491 goto exit_free;
492 break;
493 case AUDIT_GID:
494 case AUDIT_EGID:
495 case AUDIT_SGID:
496 case AUDIT_FSGID:
497 case AUDIT_OBJ_GID:
498 f->gid = make_kgid(current_user_ns(), f_val);
499 if (!gid_valid(f->gid))
500 goto exit_free;
501 break;
502 case AUDIT_ARCH:
503 f->val = f_val;
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 err = PTR_ERR(str);
519 goto exit_free;
520 }
521 entry->rule.buflen += f_val;
522 f->lsm_str = str;
523 err = security_audit_rule_init(f->type, f->op, str,
524 (void **)&f->lsm_rule);
525 /* Keep currently invalid fields around in case they
526 * become valid after a policy reload. */
527 if (err == -EINVAL) {
528 pr_warn("audit rule for LSM \'%s\' is invalid\n",
529 str);
530 err = 0;
531 } else if (err)
532 goto exit_free;
533 break;
534 case AUDIT_WATCH:
535 str = audit_unpack_string(&bufp, &remain, f_val);
536 if (IS_ERR(str)) {
537 err = PTR_ERR(str);
538 goto exit_free;
539 }
540 err = audit_to_watch(&entry->rule, str, f_val, f->op);
541 if (err) {
542 kfree(str);
543 goto exit_free;
544 }
545 entry->rule.buflen += f_val;
546 break;
547 case AUDIT_DIR:
548 str = audit_unpack_string(&bufp, &remain, f_val);
549 if (IS_ERR(str)) {
550 err = PTR_ERR(str);
551 goto exit_free;
552 }
553 err = audit_make_tree(&entry->rule, str, f->op);
554 kfree(str);
555 if (err)
556 goto exit_free;
557 entry->rule.buflen += f_val;
558 break;
559 case AUDIT_INODE:
560 f->val = f_val;
561 err = audit_to_inode(&entry->rule, f);
562 if (err)
563 goto exit_free;
564 break;
565 case AUDIT_FILTERKEY:
566 if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
567 goto exit_free;
568 str = audit_unpack_string(&bufp, &remain, f_val);
569 if (IS_ERR(str)) {
570 err = PTR_ERR(str);
571 goto exit_free;
572 }
573 entry->rule.buflen += f_val;
574 entry->rule.filterkey = str;
575 break;
576 case AUDIT_EXE:
577 if (entry->rule.exe || f_val > PATH_MAX)
578 goto exit_free;
579 str = audit_unpack_string(&bufp, &remain, f_val);
580 if (IS_ERR(str)) {
581 err = PTR_ERR(str);
582 goto exit_free;
583 }
584 audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
585 if (IS_ERR(audit_mark)) {
586 kfree(str);
587 err = PTR_ERR(audit_mark);
588 goto exit_free;
589 }
590 entry->rule.buflen += f_val;
591 entry->rule.exe = audit_mark;
592 break;
593 default:
594 f->val = f_val;
595 break;
596 }
597 }
598
599 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
600 entry->rule.inode_f = NULL;
601
602exit_nofree:
603 return entry;
604
605exit_free:
606 if (entry->rule.tree)
607 audit_put_tree(entry->rule.tree); /* that's the temporary one */
608 if (entry->rule.exe)
609 audit_remove_mark(entry->rule.exe); /* that's the template one */
610 audit_free_rule(entry);
611 return ERR_PTR(err);
612}
613
614/* Pack a filter field's string representation into data block. */
615static inline size_t audit_pack_string(void **bufp, const char *str)
616{
617 size_t len = strlen(str);
618
619 memcpy(*bufp, str, len);
620 *bufp += len;
621
622 return len;
623}
624
625/* Translate kernel rule representation to struct audit_rule_data. */
626static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
627{
628 struct audit_rule_data *data;
629 void *bufp;
630 int i;
631
632 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
633 if (unlikely(!data))
634 return NULL;
635 memset(data, 0, sizeof(*data));
636
637 data->flags = krule->flags | krule->listnr;
638 data->action = krule->action;
639 data->field_count = krule->field_count;
640 bufp = data->buf;
641 for (i = 0; i < data->field_count; i++) {
642 struct audit_field *f = &krule->fields[i];
643
644 data->fields[i] = f->type;
645 data->fieldflags[i] = audit_ops[f->op];
646 switch(f->type) {
647 case AUDIT_SUBJ_USER:
648 case AUDIT_SUBJ_ROLE:
649 case AUDIT_SUBJ_TYPE:
650 case AUDIT_SUBJ_SEN:
651 case AUDIT_SUBJ_CLR:
652 case AUDIT_OBJ_USER:
653 case AUDIT_OBJ_ROLE:
654 case AUDIT_OBJ_TYPE:
655 case AUDIT_OBJ_LEV_LOW:
656 case AUDIT_OBJ_LEV_HIGH:
657 data->buflen += data->values[i] =
658 audit_pack_string(&bufp, f->lsm_str);
659 break;
660 case AUDIT_WATCH:
661 data->buflen += data->values[i] =
662 audit_pack_string(&bufp,
663 audit_watch_path(krule->watch));
664 break;
665 case AUDIT_DIR:
666 data->buflen += data->values[i] =
667 audit_pack_string(&bufp,
668 audit_tree_path(krule->tree));
669 break;
670 case AUDIT_FILTERKEY:
671 data->buflen += data->values[i] =
672 audit_pack_string(&bufp, krule->filterkey);
673 break;
674 case AUDIT_EXE:
675 data->buflen += data->values[i] =
676 audit_pack_string(&bufp, audit_mark_path(krule->exe));
677 break;
678 case AUDIT_LOGINUID_SET:
679 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
680 data->fields[i] = AUDIT_LOGINUID;
681 data->values[i] = AUDIT_UID_UNSET;
682 break;
683 }
684 fallthrough; /* if set */
685 default:
686 data->values[i] = f->val;
687 }
688 }
689 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
690
691 return data;
692}
693
694/* Compare two rules in kernel format. Considered success if rules
695 * don't match. */
696static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
697{
698 int i;
699
700 if (a->flags != b->flags ||
701 a->pflags != b->pflags ||
702 a->listnr != b->listnr ||
703 a->action != b->action ||
704 a->field_count != b->field_count)
705 return 1;
706
707 for (i = 0; i < a->field_count; i++) {
708 if (a->fields[i].type != b->fields[i].type ||
709 a->fields[i].op != b->fields[i].op)
710 return 1;
711
712 switch(a->fields[i].type) {
713 case AUDIT_SUBJ_USER:
714 case AUDIT_SUBJ_ROLE:
715 case AUDIT_SUBJ_TYPE:
716 case AUDIT_SUBJ_SEN:
717 case AUDIT_SUBJ_CLR:
718 case AUDIT_OBJ_USER:
719 case AUDIT_OBJ_ROLE:
720 case AUDIT_OBJ_TYPE:
721 case AUDIT_OBJ_LEV_LOW:
722 case AUDIT_OBJ_LEV_HIGH:
723 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
724 return 1;
725 break;
726 case AUDIT_WATCH:
727 if (strcmp(audit_watch_path(a->watch),
728 audit_watch_path(b->watch)))
729 return 1;
730 break;
731 case AUDIT_DIR:
732 if (strcmp(audit_tree_path(a->tree),
733 audit_tree_path(b->tree)))
734 return 1;
735 break;
736 case AUDIT_FILTERKEY:
737 /* both filterkeys exist based on above type compare */
738 if (strcmp(a->filterkey, b->filterkey))
739 return 1;
740 break;
741 case AUDIT_EXE:
742 /* both paths exist based on above type compare */
743 if (strcmp(audit_mark_path(a->exe),
744 audit_mark_path(b->exe)))
745 return 1;
746 break;
747 case AUDIT_UID:
748 case AUDIT_EUID:
749 case AUDIT_SUID:
750 case AUDIT_FSUID:
751 case AUDIT_LOGINUID:
752 case AUDIT_OBJ_UID:
753 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
754 return 1;
755 break;
756 case AUDIT_GID:
757 case AUDIT_EGID:
758 case AUDIT_SGID:
759 case AUDIT_FSGID:
760 case AUDIT_OBJ_GID:
761 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
762 return 1;
763 break;
764 default:
765 if (a->fields[i].val != b->fields[i].val)
766 return 1;
767 }
768 }
769
770 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
771 if (a->mask[i] != b->mask[i])
772 return 1;
773
774 return 0;
775}
776
777/* Duplicate LSM field information. The lsm_rule is opaque, so must be
778 * re-initialized. */
779static inline int audit_dupe_lsm_field(struct audit_field *df,
780 struct audit_field *sf)
781{
782 int ret = 0;
783 char *lsm_str;
784
785 /* our own copy of lsm_str */
786 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
787 if (unlikely(!lsm_str))
788 return -ENOMEM;
789 df->lsm_str = lsm_str;
790
791 /* our own (refreshed) copy of lsm_rule */
792 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
793 (void **)&df->lsm_rule);
794 /* Keep currently invalid fields around in case they
795 * become valid after a policy reload. */
796 if (ret == -EINVAL) {
797 pr_warn("audit rule for LSM \'%s\' is invalid\n",
798 df->lsm_str);
799 ret = 0;
800 }
801
802 return ret;
803}
804
805/* Duplicate an audit rule. This will be a deep copy with the exception
806 * of the watch - that pointer is carried over. The LSM specific fields
807 * will be updated in the copy. The point is to be able to replace the old
808 * rule with the new rule in the filterlist, then free the old rule.
809 * The rlist element is undefined; list manipulations are handled apart from
810 * the initial copy. */
811struct audit_entry *audit_dupe_rule(struct audit_krule *old)
812{
813 u32 fcount = old->field_count;
814 struct audit_entry *entry;
815 struct audit_krule *new;
816 char *fk;
817 int i, err = 0;
818
819 entry = audit_init_entry(fcount);
820 if (unlikely(!entry))
821 return ERR_PTR(-ENOMEM);
822
823 new = &entry->rule;
824 new->flags = old->flags;
825 new->pflags = old->pflags;
826 new->listnr = old->listnr;
827 new->action = old->action;
828 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
829 new->mask[i] = old->mask[i];
830 new->prio = old->prio;
831 new->buflen = old->buflen;
832 new->inode_f = old->inode_f;
833 new->field_count = old->field_count;
834
835 /*
836 * note that we are OK with not refcounting here; audit_match_tree()
837 * never dereferences tree and we can't get false positives there
838 * since we'd have to have rule gone from the list *and* removed
839 * before the chunks found by lookup had been allocated, i.e. before
840 * the beginning of list scan.
841 */
842 new->tree = old->tree;
843 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
844
845 /* deep copy this information, updating the lsm_rule fields, because
846 * the originals will all be freed when the old rule is freed. */
847 for (i = 0; i < fcount; i++) {
848 switch (new->fields[i].type) {
849 case AUDIT_SUBJ_USER:
850 case AUDIT_SUBJ_ROLE:
851 case AUDIT_SUBJ_TYPE:
852 case AUDIT_SUBJ_SEN:
853 case AUDIT_SUBJ_CLR:
854 case AUDIT_OBJ_USER:
855 case AUDIT_OBJ_ROLE:
856 case AUDIT_OBJ_TYPE:
857 case AUDIT_OBJ_LEV_LOW:
858 case AUDIT_OBJ_LEV_HIGH:
859 err = audit_dupe_lsm_field(&new->fields[i],
860 &old->fields[i]);
861 break;
862 case AUDIT_FILTERKEY:
863 fk = kstrdup(old->filterkey, GFP_KERNEL);
864 if (unlikely(!fk))
865 err = -ENOMEM;
866 else
867 new->filterkey = fk;
868 break;
869 case AUDIT_EXE:
870 err = audit_dupe_exe(new, old);
871 break;
872 }
873 if (err) {
874 if (new->exe)
875 audit_remove_mark(new->exe);
876 audit_free_rule(entry);
877 return ERR_PTR(err);
878 }
879 }
880
881 if (old->watch) {
882 audit_get_watch(old->watch);
883 new->watch = old->watch;
884 }
885
886 return entry;
887}
888
889/* Find an existing audit rule.
890 * Caller must hold audit_filter_mutex to prevent stale rule data. */
891static struct audit_entry *audit_find_rule(struct audit_entry *entry,
892 struct list_head **p)
893{
894 struct audit_entry *e, *found = NULL;
895 struct list_head *list;
896 int h;
897
898 if (entry->rule.inode_f) {
899 h = audit_hash_ino(entry->rule.inode_f->val);
900 *p = list = &audit_inode_hash[h];
901 } else if (entry->rule.watch) {
902 /* we don't know the inode number, so must walk entire hash */
903 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
904 list = &audit_inode_hash[h];
905 list_for_each_entry(e, list, list)
906 if (!audit_compare_rule(&entry->rule, &e->rule)) {
907 found = e;
908 goto out;
909 }
910 }
911 goto out;
912 } else {
913 *p = list = &audit_filter_list[entry->rule.listnr];
914 }
915
916 list_for_each_entry(e, list, list)
917 if (!audit_compare_rule(&entry->rule, &e->rule)) {
918 found = e;
919 goto out;
920 }
921
922out:
923 return found;
924}
925
926static u64 prio_low = ~0ULL/2;
927static u64 prio_high = ~0ULL/2 - 1;
928
929/* Add rule to given filterlist if not a duplicate. */
930static inline int audit_add_rule(struct audit_entry *entry)
931{
932 struct audit_entry *e;
933 struct audit_watch *watch = entry->rule.watch;
934 struct audit_tree *tree = entry->rule.tree;
935 struct list_head *list;
936 int err = 0;
937#ifdef CONFIG_AUDITSYSCALL
938 int dont_count = 0;
939
940 /* If any of these, don't count towards total */
941 switch(entry->rule.listnr) {
942 case AUDIT_FILTER_USER:
943 case AUDIT_FILTER_EXCLUDE:
944 case AUDIT_FILTER_FS:
945 dont_count = 1;
946 }
947#endif
948
949 mutex_lock(&audit_filter_mutex);
950 e = audit_find_rule(entry, &list);
951 if (e) {
952 mutex_unlock(&audit_filter_mutex);
953 err = -EEXIST;
954 /* normally audit_add_tree_rule() will free it on failure */
955 if (tree)
956 audit_put_tree(tree);
957 return err;
958 }
959
960 if (watch) {
961 /* audit_filter_mutex is dropped and re-taken during this call */
962 err = audit_add_watch(&entry->rule, &list);
963 if (err) {
964 mutex_unlock(&audit_filter_mutex);
965 /*
966 * normally audit_add_tree_rule() will free it
967 * on failure
968 */
969 if (tree)
970 audit_put_tree(tree);
971 return err;
972 }
973 }
974 if (tree) {
975 err = audit_add_tree_rule(&entry->rule);
976 if (err) {
977 mutex_unlock(&audit_filter_mutex);
978 return err;
979 }
980 }
981
982 entry->rule.prio = ~0ULL;
983 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
984 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
985 entry->rule.prio = ++prio_high;
986 else
987 entry->rule.prio = --prio_low;
988 }
989
990 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
991 list_add(&entry->rule.list,
992 &audit_rules_list[entry->rule.listnr]);
993 list_add_rcu(&entry->list, list);
994 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
995 } else {
996 list_add_tail(&entry->rule.list,
997 &audit_rules_list[entry->rule.listnr]);
998 list_add_tail_rcu(&entry->list, list);
999 }
1000#ifdef CONFIG_AUDITSYSCALL
1001 if (!dont_count)
1002 audit_n_rules++;
1003
1004 if (!audit_match_signal(entry))
1005 audit_signals++;
1006#endif
1007 mutex_unlock(&audit_filter_mutex);
1008
1009 return err;
1010}
1011
1012/* Remove an existing rule from filterlist. */
1013int audit_del_rule(struct audit_entry *entry)
1014{
1015 struct audit_entry *e;
1016 struct audit_tree *tree = entry->rule.tree;
1017 struct list_head *list;
1018 int ret = 0;
1019#ifdef CONFIG_AUDITSYSCALL
1020 int dont_count = 0;
1021
1022 /* If any of these, don't count towards total */
1023 switch(entry->rule.listnr) {
1024 case AUDIT_FILTER_USER:
1025 case AUDIT_FILTER_EXCLUDE:
1026 case AUDIT_FILTER_FS:
1027 dont_count = 1;
1028 }
1029#endif
1030
1031 mutex_lock(&audit_filter_mutex);
1032 e = audit_find_rule(entry, &list);
1033 if (!e) {
1034 ret = -ENOENT;
1035 goto out;
1036 }
1037
1038 if (e->rule.watch)
1039 audit_remove_watch_rule(&e->rule);
1040
1041 if (e->rule.tree)
1042 audit_remove_tree_rule(&e->rule);
1043
1044 if (e->rule.exe)
1045 audit_remove_mark_rule(&e->rule);
1046
1047#ifdef CONFIG_AUDITSYSCALL
1048 if (!dont_count)
1049 audit_n_rules--;
1050
1051 if (!audit_match_signal(entry))
1052 audit_signals--;
1053#endif
1054
1055 list_del_rcu(&e->list);
1056 list_del(&e->rule.list);
1057 call_rcu(&e->rcu, audit_free_rule_rcu);
1058
1059out:
1060 mutex_unlock(&audit_filter_mutex);
1061
1062 if (tree)
1063 audit_put_tree(tree); /* that's the temporary one */
1064
1065 return ret;
1066}
1067
1068/* List rules using struct audit_rule_data. */
1069static void audit_list_rules(int seq, struct sk_buff_head *q)
1070{
1071 struct sk_buff *skb;
1072 struct audit_krule *r;
1073 int i;
1074
1075 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1076 * iterator to sync with list writers. */
1077 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1078 list_for_each_entry(r, &audit_rules_list[i], list) {
1079 struct audit_rule_data *data;
1080
1081 data = audit_krule_to_data(r);
1082 if (unlikely(!data))
1083 break;
1084 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1085 data,
1086 sizeof(*data) + data->buflen);
1087 if (skb)
1088 skb_queue_tail(q, skb);
1089 kfree(data);
1090 }
1091 }
1092 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1093 if (skb)
1094 skb_queue_tail(q, skb);
1095}
1096
1097/* Log rule additions and removals */
1098static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1099{
1100 struct audit_buffer *ab;
1101
1102 if (!audit_enabled)
1103 return;
1104
1105 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1106 if (!ab)
1107 return;
1108 audit_log_session_info(ab);
1109 audit_log_task_context(ab);
1110 audit_log_format(ab, " op=%s", action);
1111 audit_log_key(ab, rule->filterkey);
1112 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1113 audit_log_end(ab);
1114}
1115
1116/**
1117 * audit_rule_change - apply all rules to the specified message type
1118 * @type: audit message type
1119 * @seq: netlink audit message sequence (serial) number
1120 * @data: payload data
1121 * @datasz: size of payload data
1122 */
1123int audit_rule_change(int type, int seq, void *data, size_t datasz)
1124{
1125 int err = 0;
1126 struct audit_entry *entry;
1127
1128 switch (type) {
1129 case AUDIT_ADD_RULE:
1130 entry = audit_data_to_entry(data, datasz);
1131 if (IS_ERR(entry))
1132 return PTR_ERR(entry);
1133 err = audit_add_rule(entry);
1134 audit_log_rule_change("add_rule", &entry->rule, !err);
1135 break;
1136 case AUDIT_DEL_RULE:
1137 entry = audit_data_to_entry(data, datasz);
1138 if (IS_ERR(entry))
1139 return PTR_ERR(entry);
1140 err = audit_del_rule(entry);
1141 audit_log_rule_change("remove_rule", &entry->rule, !err);
1142 break;
1143 default:
1144 WARN_ON(1);
1145 return -EINVAL;
1146 }
1147
1148 if (err || type == AUDIT_DEL_RULE) {
1149 if (entry->rule.exe)
1150 audit_remove_mark(entry->rule.exe);
1151 audit_free_rule(entry);
1152 }
1153
1154 return err;
1155}
1156
1157/**
1158 * audit_list_rules_send - list the audit rules
1159 * @request_skb: skb of request we are replying to (used to target the reply)
1160 * @seq: netlink audit message sequence (serial) number
1161 */
1162int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1163{
1164 struct task_struct *tsk;
1165 struct audit_netlink_list *dest;
1166
1167 /* We can't just spew out the rules here because we might fill
1168 * the available socket buffer space and deadlock waiting for
1169 * auditctl to read from it... which isn't ever going to
1170 * happen if we're actually running in the context of auditctl
1171 * trying to _send_ the stuff */
1172
1173 dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1174 if (!dest)
1175 return -ENOMEM;
1176 dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1177 dest->portid = NETLINK_CB(request_skb).portid;
1178 skb_queue_head_init(&dest->q);
1179
1180 mutex_lock(&audit_filter_mutex);
1181 audit_list_rules(seq, &dest->q);
1182 mutex_unlock(&audit_filter_mutex);
1183
1184 tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1185 if (IS_ERR(tsk)) {
1186 skb_queue_purge(&dest->q);
1187 put_net(dest->net);
1188 kfree(dest);
1189 return PTR_ERR(tsk);
1190 }
1191
1192 return 0;
1193}
1194
1195int audit_comparator(u32 left, u32 op, u32 right)
1196{
1197 switch (op) {
1198 case Audit_equal:
1199 return (left == right);
1200 case Audit_not_equal:
1201 return (left != right);
1202 case Audit_lt:
1203 return (left < right);
1204 case Audit_le:
1205 return (left <= right);
1206 case Audit_gt:
1207 return (left > right);
1208 case Audit_ge:
1209 return (left >= right);
1210 case Audit_bitmask:
1211 return (left & right);
1212 case Audit_bittest:
1213 return ((left & right) == right);
1214 default:
1215 return 0;
1216 }
1217}
1218
1219int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1220{
1221 switch (op) {
1222 case Audit_equal:
1223 return uid_eq(left, right);
1224 case Audit_not_equal:
1225 return !uid_eq(left, right);
1226 case Audit_lt:
1227 return uid_lt(left, right);
1228 case Audit_le:
1229 return uid_lte(left, right);
1230 case Audit_gt:
1231 return uid_gt(left, right);
1232 case Audit_ge:
1233 return uid_gte(left, right);
1234 case Audit_bitmask:
1235 case Audit_bittest:
1236 default:
1237 return 0;
1238 }
1239}
1240
1241int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1242{
1243 switch (op) {
1244 case Audit_equal:
1245 return gid_eq(left, right);
1246 case Audit_not_equal:
1247 return !gid_eq(left, right);
1248 case Audit_lt:
1249 return gid_lt(left, right);
1250 case Audit_le:
1251 return gid_lte(left, right);
1252 case Audit_gt:
1253 return gid_gt(left, right);
1254 case Audit_ge:
1255 return gid_gte(left, right);
1256 case Audit_bitmask:
1257 case Audit_bittest:
1258 default:
1259 return 0;
1260 }
1261}
1262
1263/**
1264 * parent_len - find the length of the parent portion of a pathname
1265 * @path: pathname of which to determine length
1266 */
1267int parent_len(const char *path)
1268{
1269 int plen;
1270 const char *p;
1271
1272 plen = strlen(path);
1273
1274 if (plen == 0)
1275 return plen;
1276
1277 /* disregard trailing slashes */
1278 p = path + plen - 1;
1279 while ((*p == '/') && (p > path))
1280 p--;
1281
1282 /* walk backward until we find the next slash or hit beginning */
1283 while ((*p != '/') && (p > path))
1284 p--;
1285
1286 /* did we find a slash? Then increment to include it in path */
1287 if (*p == '/')
1288 p++;
1289
1290 return p - path;
1291}
1292
1293/**
1294 * audit_compare_dname_path - compare given dentry name with last component in
1295 * given path. Return of 0 indicates a match.
1296 * @dname: dentry name that we're comparing
1297 * @path: full pathname that we're comparing
1298 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1299 * here indicates that we must compute this value.
1300 */
1301int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1302{
1303 int dlen, pathlen;
1304 const char *p;
1305
1306 dlen = dname->len;
1307 pathlen = strlen(path);
1308 if (pathlen < dlen)
1309 return 1;
1310
1311 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1312 if (pathlen - parentlen != dlen)
1313 return 1;
1314
1315 p = path + parentlen;
1316
1317 return strncmp(p, dname->name, dlen);
1318}
1319
1320int audit_filter(int msgtype, unsigned int listtype)
1321{
1322 struct audit_entry *e;
1323 int ret = 1; /* Audit by default */
1324
1325 rcu_read_lock();
1326 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1327 int i, result = 0;
1328
1329 for (i = 0; i < e->rule.field_count; i++) {
1330 struct audit_field *f = &e->rule.fields[i];
1331 pid_t pid;
1332 u32 sid;
1333
1334 switch (f->type) {
1335 case AUDIT_PID:
1336 pid = task_pid_nr(current);
1337 result = audit_comparator(pid, f->op, f->val);
1338 break;
1339 case AUDIT_UID:
1340 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1341 break;
1342 case AUDIT_GID:
1343 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1344 break;
1345 case AUDIT_LOGINUID:
1346 result = audit_uid_comparator(audit_get_loginuid(current),
1347 f->op, f->uid);
1348 break;
1349 case AUDIT_LOGINUID_SET:
1350 result = audit_comparator(audit_loginuid_set(current),
1351 f->op, f->val);
1352 break;
1353 case AUDIT_MSGTYPE:
1354 result = audit_comparator(msgtype, f->op, f->val);
1355 break;
1356 case AUDIT_SUBJ_USER:
1357 case AUDIT_SUBJ_ROLE:
1358 case AUDIT_SUBJ_TYPE:
1359 case AUDIT_SUBJ_SEN:
1360 case AUDIT_SUBJ_CLR:
1361 if (f->lsm_rule) {
1362 security_task_getsecid_subj(current,
1363 &sid);
1364 result = security_audit_rule_match(sid,
1365 f->type, f->op, f->lsm_rule);
1366 }
1367 break;
1368 case AUDIT_EXE:
1369 result = audit_exe_compare(current, e->rule.exe);
1370 if (f->op == Audit_not_equal)
1371 result = !result;
1372 break;
1373 default:
1374 goto unlock_and_return;
1375 }
1376 if (result < 0) /* error */
1377 goto unlock_and_return;
1378 if (!result)
1379 break;
1380 }
1381 if (result > 0) {
1382 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1383 ret = 0;
1384 break;
1385 }
1386 }
1387unlock_and_return:
1388 rcu_read_unlock();
1389 return ret;
1390}
1391
1392static int update_lsm_rule(struct audit_krule *r)
1393{
1394 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1395 struct audit_entry *nentry;
1396 int err = 0;
1397
1398 if (!security_audit_rule_known(r))
1399 return 0;
1400
1401 nentry = audit_dupe_rule(r);
1402 if (entry->rule.exe)
1403 audit_remove_mark(entry->rule.exe);
1404 if (IS_ERR(nentry)) {
1405 /* save the first error encountered for the
1406 * return value */
1407 err = PTR_ERR(nentry);
1408 audit_panic("error updating LSM filters");
1409 if (r->watch)
1410 list_del(&r->rlist);
1411 list_del_rcu(&entry->list);
1412 list_del(&r->list);
1413 } else {
1414 if (r->watch || r->tree)
1415 list_replace_init(&r->rlist, &nentry->rule.rlist);
1416 list_replace_rcu(&entry->list, &nentry->list);
1417 list_replace(&r->list, &nentry->rule.list);
1418 }
1419 call_rcu(&entry->rcu, audit_free_rule_rcu);
1420
1421 return err;
1422}
1423
1424/* This function will re-initialize the lsm_rule field of all applicable rules.
1425 * It will traverse the filter lists serarching for rules that contain LSM
1426 * specific filter fields. When such a rule is found, it is copied, the
1427 * LSM field is re-initialized, and the old rule is replaced with the
1428 * updated rule. */
1429int audit_update_lsm_rules(void)
1430{
1431 struct audit_krule *r, *n;
1432 int i, err = 0;
1433
1434 /* audit_filter_mutex synchronizes the writers */
1435 mutex_lock(&audit_filter_mutex);
1436
1437 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1438 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1439 int res = update_lsm_rule(r);
1440 if (!err)
1441 err = res;
1442 }
1443 }
1444 mutex_unlock(&audit_filter_mutex);
1445
1446 return err;
1447}