1 /* auditfilter.c -- filtering of audit events
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
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.
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.
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
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/kernel.h>
25 #include <linux/audit.h>
26 #include <linux/kthread.h>
27 #include <linux/mutex.h>
29 #include <linux/namei.h>
30 #include <linux/netlink.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/security.h>
34 #include <net/net_namespace.h>
42 * Synchronizes writes and blocking reads of audit's filterlist
43 * data. Rcu is used to traverse the filterlist and access
44 * contents of structs audit_entry, audit_watch and opaque
45 * LSM rules during filtering. If modified, these structures
46 * must be copied and replace their counterparts in the filterlist.
47 * An audit_parent struct is not accessed during filtering, so may
48 * be written directly provided audit_filter_mutex is held.
51 /* Audit filter lists, defined in <linux/audit.h> */
52 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
53 LIST_HEAD_INIT(audit_filter_list[0]),
54 LIST_HEAD_INIT(audit_filter_list[1]),
55 LIST_HEAD_INIT(audit_filter_list[2]),
56 LIST_HEAD_INIT(audit_filter_list[3]),
57 LIST_HEAD_INIT(audit_filter_list[4]),
58 LIST_HEAD_INIT(audit_filter_list[5]),
59 LIST_HEAD_INIT(audit_filter_list[6]),
60 #if AUDIT_NR_FILTERS != 7
61 #error Fix audit_filter_list initialiser
64 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
65 LIST_HEAD_INIT(audit_rules_list[0]),
66 LIST_HEAD_INIT(audit_rules_list[1]),
67 LIST_HEAD_INIT(audit_rules_list[2]),
68 LIST_HEAD_INIT(audit_rules_list[3]),
69 LIST_HEAD_INIT(audit_rules_list[4]),
70 LIST_HEAD_INIT(audit_rules_list[5]),
71 LIST_HEAD_INIT(audit_rules_list[6]),
74 DEFINE_MUTEX(audit_filter_mutex);
76 static void audit_free_lsm_field(struct audit_field *f)
87 case AUDIT_OBJ_LEV_LOW:
88 case AUDIT_OBJ_LEV_HIGH:
90 security_audit_rule_free(f->lsm_rule);
94 static inline void audit_free_rule(struct audit_entry *e)
97 struct audit_krule *erule = &e->rule;
99 /* some rules don't have associated watches */
101 audit_put_watch(erule->watch);
103 for (i = 0; i < erule->field_count; i++)
104 audit_free_lsm_field(&erule->fields[i]);
105 kfree(erule->fields);
106 kfree(erule->filterkey);
110 void audit_free_rule_rcu(struct rcu_head *head)
112 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
116 /* Initialize an audit filterlist entry. */
117 static inline struct audit_entry *audit_init_entry(u32 field_count)
119 struct audit_entry *entry;
120 struct audit_field *fields;
122 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
123 if (unlikely(!entry))
126 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
127 if (unlikely(!fields)) {
131 entry->rule.fields = fields;
136 /* Unpack a filter field's string representation from user-space
138 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
142 if (!*bufp || (len == 0) || (len > *remain))
143 return ERR_PTR(-EINVAL);
145 /* Of the currently implemented string fields, PATH_MAX
146 * defines the longest valid length.
149 return ERR_PTR(-ENAMETOOLONG);
151 str = kmalloc(len + 1, GFP_KERNEL);
153 return ERR_PTR(-ENOMEM);
155 memcpy(str, *bufp, len);
163 /* Translate an inode field to kernel representation. */
164 static inline int audit_to_inode(struct audit_krule *krule,
165 struct audit_field *f)
167 if (krule->listnr != AUDIT_FILTER_EXIT ||
168 krule->inode_f || krule->watch || krule->tree ||
169 (f->op != Audit_equal && f->op != Audit_not_equal))
176 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
178 int __init audit_register_class(int class, unsigned *list)
180 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
183 while (*list != ~0U) {
184 unsigned n = *list++;
185 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
189 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
191 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
199 int audit_match_class(int class, unsigned syscall)
201 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
203 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
205 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
208 #ifdef CONFIG_AUDITSYSCALL
209 static inline int audit_match_class_bits(int class, u32 *mask)
213 if (classes[class]) {
214 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
215 if (mask[i] & classes[class][i])
221 static int audit_match_signal(struct audit_entry *entry)
223 struct audit_field *arch = entry->rule.arch_f;
226 /* When arch is unspecified, we must check both masks on biarch
227 * as syscall number alone is ambiguous. */
228 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
230 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
234 switch(audit_classify_arch(arch->val)) {
236 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
238 case 1: /* 32bit on biarch */
239 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
247 /* Common user-space to kernel rule translation. */
248 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
251 struct audit_entry *entry;
255 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
259 #ifdef CONFIG_AUDITSYSCALL
260 case AUDIT_FILTER_ENTRY:
261 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
263 case AUDIT_FILTER_EXIT:
264 case AUDIT_FILTER_TASK:
266 case AUDIT_FILTER_USER:
267 case AUDIT_FILTER_EXCLUDE:
268 case AUDIT_FILTER_FS:
271 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
272 pr_err("AUDIT_POSSIBLE is deprecated\n");
275 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
277 if (rule->field_count > AUDIT_MAX_FIELDS)
281 entry = audit_init_entry(rule->field_count);
285 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
286 entry->rule.listnr = listnr;
287 entry->rule.action = rule->action;
288 entry->rule.field_count = rule->field_count;
290 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
291 entry->rule.mask[i] = rule->mask[i];
293 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
294 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
295 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
298 if (!(*p & AUDIT_BIT(bit)))
300 *p &= ~AUDIT_BIT(bit);
304 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
305 entry->rule.mask[j] |= class[j];
315 static u32 audit_ops[] =
317 [Audit_equal] = AUDIT_EQUAL,
318 [Audit_not_equal] = AUDIT_NOT_EQUAL,
319 [Audit_bitmask] = AUDIT_BIT_MASK,
320 [Audit_bittest] = AUDIT_BIT_TEST,
321 [Audit_lt] = AUDIT_LESS_THAN,
322 [Audit_gt] = AUDIT_GREATER_THAN,
323 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
324 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
327 static u32 audit_to_op(u32 op)
330 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
335 /* check if an audit field is valid */
336 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
340 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
341 entry->rule.listnr != AUDIT_FILTER_USER)
345 if (entry->rule.listnr != AUDIT_FILTER_FS)
350 switch (entry->rule.listnr) {
351 case AUDIT_FILTER_FS:
354 case AUDIT_FILTERKEY:
361 /* Check for valid field type and op */
367 case AUDIT_PERS: /* <uapi/linux/personality.h> */
369 /* all ops are valid */
389 case AUDIT_SESSIONID:
392 case AUDIT_OBJ_LEV_LOW:
393 case AUDIT_OBJ_LEV_HIGH:
394 case AUDIT_SADDR_FAM:
395 /* bit ops are only useful on syscall args */
396 if (f->op == Audit_bitmask || f->op == Audit_bittest)
399 case AUDIT_SUBJ_USER:
400 case AUDIT_SUBJ_ROLE:
401 case AUDIT_SUBJ_TYPE:
407 case AUDIT_FILTERKEY:
408 case AUDIT_LOGINUID_SET:
413 case AUDIT_FIELD_COMPARE:
415 /* only equal and not equal valid ops */
416 if (f->op != Audit_not_equal && f->op != Audit_equal)
420 /* field not recognized */
424 /* Check for select valid field values */
426 case AUDIT_LOGINUID_SET:
427 if ((f->val != 0) && (f->val != 1))
435 if (f->val & ~S_IFMT)
438 case AUDIT_FIELD_COMPARE:
439 if (f->val > AUDIT_MAX_FIELD_COMPARE)
442 case AUDIT_SADDR_FAM:
443 if (f->val >= AF_MAX)
453 /* Translate struct audit_rule_data to kernel's rule representation. */
454 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
458 struct audit_entry *entry;
460 size_t remain = datasz - sizeof(struct audit_rule_data);
463 struct audit_fsnotify_mark *audit_mark;
465 entry = audit_to_entry_common(data);
470 for (i = 0; i < data->field_count; i++) {
471 struct audit_field *f = &entry->rule.fields[i];
475 f->op = audit_to_op(data->fieldflags[i]);
476 if (f->op == Audit_bad)
479 f->type = data->fields[i];
480 f->val = data->values[i];
482 /* Support legacy tests for a valid loginuid */
483 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
484 f->type = AUDIT_LOGINUID_SET;
486 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
489 err = audit_field_valid(entry, f);
501 f->uid = make_kuid(current_user_ns(), f->val);
502 if (!uid_valid(f->uid))
510 f->gid = make_kgid(current_user_ns(), f->val);
511 if (!gid_valid(f->gid))
515 entry->rule.arch_f = f;
517 case AUDIT_SUBJ_USER:
518 case AUDIT_SUBJ_ROLE:
519 case AUDIT_SUBJ_TYPE:
525 case AUDIT_OBJ_LEV_LOW:
526 case AUDIT_OBJ_LEV_HIGH:
527 str = audit_unpack_string(&bufp, &remain, f->val);
530 entry->rule.buflen += f->val;
532 err = security_audit_rule_init(f->type, f->op, str,
533 (void **)&f->lsm_rule);
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",
548 str = audit_unpack_string(&bufp, &remain, f->val);
551 entry->rule.buflen += f->val;
553 err = audit_to_watch(&entry->rule, str, f->val, f->op);
560 str = audit_unpack_string(&bufp, &remain, f->val);
563 entry->rule.buflen += f->val;
565 err = audit_make_tree(&entry->rule, str, f->op);
571 err = audit_to_inode(&entry->rule, f);
575 case AUDIT_FILTERKEY:
576 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
578 str = audit_unpack_string(&bufp, &remain, f->val);
581 entry->rule.buflen += f->val;
582 entry->rule.filterkey = str;
585 if (entry->rule.exe || f->val > PATH_MAX)
587 str = audit_unpack_string(&bufp, &remain, f->val);
592 entry->rule.buflen += f->val;
594 audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
595 if (IS_ERR(audit_mark)) {
597 err = PTR_ERR(audit_mark);
600 entry->rule.exe = audit_mark;
605 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
606 entry->rule.inode_f = NULL;
612 if (entry->rule.tree)
613 audit_put_tree(entry->rule.tree); /* that's the temporary one */
615 audit_remove_mark(entry->rule.exe); /* that's the template one */
616 audit_free_rule(entry);
620 /* Pack a filter field's string representation into data block. */
621 static inline size_t audit_pack_string(void **bufp, const char *str)
623 size_t len = strlen(str);
625 memcpy(*bufp, str, len);
631 /* Translate kernel rule representation to struct audit_rule_data. */
632 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
634 struct audit_rule_data *data;
638 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
641 memset(data, 0, sizeof(*data));
643 data->flags = krule->flags | krule->listnr;
644 data->action = krule->action;
645 data->field_count = krule->field_count;
647 for (i = 0; i < data->field_count; i++) {
648 struct audit_field *f = &krule->fields[i];
650 data->fields[i] = f->type;
651 data->fieldflags[i] = audit_ops[f->op];
653 case AUDIT_SUBJ_USER:
654 case AUDIT_SUBJ_ROLE:
655 case AUDIT_SUBJ_TYPE:
661 case AUDIT_OBJ_LEV_LOW:
662 case AUDIT_OBJ_LEV_HIGH:
663 data->buflen += data->values[i] =
664 audit_pack_string(&bufp, f->lsm_str);
667 data->buflen += data->values[i] =
668 audit_pack_string(&bufp,
669 audit_watch_path(krule->watch));
672 data->buflen += data->values[i] =
673 audit_pack_string(&bufp,
674 audit_tree_path(krule->tree));
676 case AUDIT_FILTERKEY:
677 data->buflen += data->values[i] =
678 audit_pack_string(&bufp, krule->filterkey);
681 data->buflen += data->values[i] =
682 audit_pack_string(&bufp, audit_mark_path(krule->exe));
684 case AUDIT_LOGINUID_SET:
685 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
686 data->fields[i] = AUDIT_LOGINUID;
687 data->values[i] = AUDIT_UID_UNSET;
690 /* fall through - if set */
692 data->values[i] = f->val;
695 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
700 /* Compare two rules in kernel format. Considered success if rules
702 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
706 if (a->flags != b->flags ||
707 a->pflags != b->pflags ||
708 a->listnr != b->listnr ||
709 a->action != b->action ||
710 a->field_count != b->field_count)
713 for (i = 0; i < a->field_count; i++) {
714 if (a->fields[i].type != b->fields[i].type ||
715 a->fields[i].op != b->fields[i].op)
718 switch(a->fields[i].type) {
719 case AUDIT_SUBJ_USER:
720 case AUDIT_SUBJ_ROLE:
721 case AUDIT_SUBJ_TYPE:
727 case AUDIT_OBJ_LEV_LOW:
728 case AUDIT_OBJ_LEV_HIGH:
729 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
733 if (strcmp(audit_watch_path(a->watch),
734 audit_watch_path(b->watch)))
738 if (strcmp(audit_tree_path(a->tree),
739 audit_tree_path(b->tree)))
742 case AUDIT_FILTERKEY:
743 /* both filterkeys exist based on above type compare */
744 if (strcmp(a->filterkey, b->filterkey))
748 /* both paths exist based on above type compare */
749 if (strcmp(audit_mark_path(a->exe),
750 audit_mark_path(b->exe)))
759 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
767 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
771 if (a->fields[i].val != b->fields[i].val)
776 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
777 if (a->mask[i] != b->mask[i])
783 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
785 static inline int audit_dupe_lsm_field(struct audit_field *df,
786 struct audit_field *sf)
791 /* our own copy of lsm_str */
792 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
793 if (unlikely(!lsm_str))
795 df->lsm_str = lsm_str;
797 /* our own (refreshed) copy of lsm_rule */
798 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
799 (void **)&df->lsm_rule);
800 /* Keep currently invalid fields around in case they
801 * become valid after a policy reload. */
802 if (ret == -EINVAL) {
803 pr_warn("audit rule for LSM \'%s\' is invalid\n",
811 /* Duplicate an audit rule. This will be a deep copy with the exception
812 * of the watch - that pointer is carried over. The LSM specific fields
813 * will be updated in the copy. The point is to be able to replace the old
814 * rule with the new rule in the filterlist, then free the old rule.
815 * The rlist element is undefined; list manipulations are handled apart from
816 * the initial copy. */
817 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
819 u32 fcount = old->field_count;
820 struct audit_entry *entry;
821 struct audit_krule *new;
825 entry = audit_init_entry(fcount);
826 if (unlikely(!entry))
827 return ERR_PTR(-ENOMEM);
830 new->flags = old->flags;
831 new->pflags = old->pflags;
832 new->listnr = old->listnr;
833 new->action = old->action;
834 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
835 new->mask[i] = old->mask[i];
836 new->prio = old->prio;
837 new->buflen = old->buflen;
838 new->inode_f = old->inode_f;
839 new->field_count = old->field_count;
842 * note that we are OK with not refcounting here; audit_match_tree()
843 * never dereferences tree and we can't get false positives there
844 * since we'd have to have rule gone from the list *and* removed
845 * before the chunks found by lookup had been allocated, i.e. before
846 * the beginning of list scan.
848 new->tree = old->tree;
849 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
851 /* deep copy this information, updating the lsm_rule fields, because
852 * the originals will all be freed when the old rule is freed. */
853 for (i = 0; i < fcount; i++) {
854 switch (new->fields[i].type) {
855 case AUDIT_SUBJ_USER:
856 case AUDIT_SUBJ_ROLE:
857 case AUDIT_SUBJ_TYPE:
863 case AUDIT_OBJ_LEV_LOW:
864 case AUDIT_OBJ_LEV_HIGH:
865 err = audit_dupe_lsm_field(&new->fields[i],
868 case AUDIT_FILTERKEY:
869 fk = kstrdup(old->filterkey, GFP_KERNEL);
876 err = audit_dupe_exe(new, old);
881 audit_remove_mark(new->exe);
882 audit_free_rule(entry);
888 audit_get_watch(old->watch);
889 new->watch = old->watch;
895 /* Find an existing audit rule.
896 * Caller must hold audit_filter_mutex to prevent stale rule data. */
897 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
898 struct list_head **p)
900 struct audit_entry *e, *found = NULL;
901 struct list_head *list;
904 if (entry->rule.inode_f) {
905 h = audit_hash_ino(entry->rule.inode_f->val);
906 *p = list = &audit_inode_hash[h];
907 } else if (entry->rule.watch) {
908 /* we don't know the inode number, so must walk entire hash */
909 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
910 list = &audit_inode_hash[h];
911 list_for_each_entry(e, list, list)
912 if (!audit_compare_rule(&entry->rule, &e->rule)) {
919 *p = list = &audit_filter_list[entry->rule.listnr];
922 list_for_each_entry(e, list, list)
923 if (!audit_compare_rule(&entry->rule, &e->rule)) {
932 static u64 prio_low = ~0ULL/2;
933 static u64 prio_high = ~0ULL/2 - 1;
935 /* Add rule to given filterlist if not a duplicate. */
936 static inline int audit_add_rule(struct audit_entry *entry)
938 struct audit_entry *e;
939 struct audit_watch *watch = entry->rule.watch;
940 struct audit_tree *tree = entry->rule.tree;
941 struct list_head *list;
943 #ifdef CONFIG_AUDITSYSCALL
946 /* If any of these, don't count towards total */
947 switch(entry->rule.listnr) {
948 case AUDIT_FILTER_USER:
949 case AUDIT_FILTER_EXCLUDE:
950 case AUDIT_FILTER_FS:
955 mutex_lock(&audit_filter_mutex);
956 e = audit_find_rule(entry, &list);
958 mutex_unlock(&audit_filter_mutex);
960 /* normally audit_add_tree_rule() will free it on failure */
962 audit_put_tree(tree);
967 /* audit_filter_mutex is dropped and re-taken during this call */
968 err = audit_add_watch(&entry->rule, &list);
970 mutex_unlock(&audit_filter_mutex);
972 * normally audit_add_tree_rule() will free it
976 audit_put_tree(tree);
981 err = audit_add_tree_rule(&entry->rule);
983 mutex_unlock(&audit_filter_mutex);
988 entry->rule.prio = ~0ULL;
989 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
990 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
991 entry->rule.prio = ++prio_high;
993 entry->rule.prio = --prio_low;
996 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
997 list_add(&entry->rule.list,
998 &audit_rules_list[entry->rule.listnr]);
999 list_add_rcu(&entry->list, list);
1000 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1002 list_add_tail(&entry->rule.list,
1003 &audit_rules_list[entry->rule.listnr]);
1004 list_add_tail_rcu(&entry->list, list);
1006 #ifdef CONFIG_AUDITSYSCALL
1010 if (!audit_match_signal(entry))
1013 mutex_unlock(&audit_filter_mutex);
1018 /* Remove an existing rule from filterlist. */
1019 int audit_del_rule(struct audit_entry *entry)
1021 struct audit_entry *e;
1022 struct audit_tree *tree = entry->rule.tree;
1023 struct list_head *list;
1025 #ifdef CONFIG_AUDITSYSCALL
1028 /* If any of these, don't count towards total */
1029 switch(entry->rule.listnr) {
1030 case AUDIT_FILTER_USER:
1031 case AUDIT_FILTER_EXCLUDE:
1032 case AUDIT_FILTER_FS:
1037 mutex_lock(&audit_filter_mutex);
1038 e = audit_find_rule(entry, &list);
1045 audit_remove_watch_rule(&e->rule);
1048 audit_remove_tree_rule(&e->rule);
1051 audit_remove_mark_rule(&e->rule);
1053 #ifdef CONFIG_AUDITSYSCALL
1057 if (!audit_match_signal(entry))
1061 list_del_rcu(&e->list);
1062 list_del(&e->rule.list);
1063 call_rcu(&e->rcu, audit_free_rule_rcu);
1066 mutex_unlock(&audit_filter_mutex);
1069 audit_put_tree(tree); /* that's the temporary one */
1074 /* List rules using struct audit_rule_data. */
1075 static void audit_list_rules(int seq, struct sk_buff_head *q)
1077 struct sk_buff *skb;
1078 struct audit_krule *r;
1081 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1082 * iterator to sync with list writers. */
1083 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1084 list_for_each_entry(r, &audit_rules_list[i], list) {
1085 struct audit_rule_data *data;
1087 data = audit_krule_to_data(r);
1088 if (unlikely(!data))
1090 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1092 sizeof(*data) + data->buflen);
1094 skb_queue_tail(q, skb);
1098 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1100 skb_queue_tail(q, skb);
1103 /* Log rule additions and removals */
1104 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1106 struct audit_buffer *ab;
1111 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1114 audit_log_session_info(ab);
1115 audit_log_task_context(ab);
1116 audit_log_format(ab, " op=%s", action);
1117 audit_log_key(ab, rule->filterkey);
1118 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1123 * audit_rule_change - apply all rules to the specified message type
1124 * @type: audit message type
1125 * @seq: netlink audit message sequence (serial) number
1126 * @data: payload data
1127 * @datasz: size of payload data
1129 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1132 struct audit_entry *entry;
1135 case AUDIT_ADD_RULE:
1136 entry = audit_data_to_entry(data, datasz);
1138 return PTR_ERR(entry);
1139 err = audit_add_rule(entry);
1140 audit_log_rule_change("add_rule", &entry->rule, !err);
1142 case AUDIT_DEL_RULE:
1143 entry = audit_data_to_entry(data, datasz);
1145 return PTR_ERR(entry);
1146 err = audit_del_rule(entry);
1147 audit_log_rule_change("remove_rule", &entry->rule, !err);
1154 if (err || type == AUDIT_DEL_RULE) {
1155 if (entry->rule.exe)
1156 audit_remove_mark(entry->rule.exe);
1157 audit_free_rule(entry);
1164 * audit_list_rules_send - list the audit rules
1165 * @request_skb: skb of request we are replying to (used to target the reply)
1166 * @seq: netlink audit message sequence (serial) number
1168 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1170 u32 portid = NETLINK_CB(request_skb).portid;
1171 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1172 struct task_struct *tsk;
1173 struct audit_netlink_list *dest;
1176 /* We can't just spew out the rules here because we might fill
1177 * the available socket buffer space and deadlock waiting for
1178 * auditctl to read from it... which isn't ever going to
1179 * happen if we're actually running in the context of auditctl
1180 * trying to _send_ the stuff */
1182 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1185 dest->net = get_net(net);
1186 dest->portid = portid;
1187 skb_queue_head_init(&dest->q);
1189 mutex_lock(&audit_filter_mutex);
1190 audit_list_rules(seq, &dest->q);
1191 mutex_unlock(&audit_filter_mutex);
1193 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1195 skb_queue_purge(&dest->q);
1203 int audit_comparator(u32 left, u32 op, u32 right)
1207 return (left == right);
1208 case Audit_not_equal:
1209 return (left != right);
1211 return (left < right);
1213 return (left <= right);
1215 return (left > right);
1217 return (left >= right);
1219 return (left & right);
1221 return ((left & right) == right);
1228 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1232 return uid_eq(left, right);
1233 case Audit_not_equal:
1234 return !uid_eq(left, right);
1236 return uid_lt(left, right);
1238 return uid_lte(left, right);
1240 return uid_gt(left, right);
1242 return uid_gte(left, right);
1251 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1255 return gid_eq(left, right);
1256 case Audit_not_equal:
1257 return !gid_eq(left, right);
1259 return gid_lt(left, right);
1261 return gid_lte(left, right);
1263 return gid_gt(left, right);
1265 return gid_gte(left, right);
1275 * parent_len - find the length of the parent portion of a pathname
1276 * @path: pathname of which to determine length
1278 int parent_len(const char *path)
1283 plen = strlen(path);
1288 /* disregard trailing slashes */
1289 p = path + plen - 1;
1290 while ((*p == '/') && (p > path))
1293 /* walk backward until we find the next slash or hit beginning */
1294 while ((*p != '/') && (p > path))
1297 /* did we find a slash? Then increment to include it in path */
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.
1312 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1318 pathlen = strlen(path);
1322 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1323 if (pathlen - parentlen != dlen)
1326 p = path + parentlen;
1328 return strncmp(p, dname->name, dlen);
1331 int audit_filter(int msgtype, unsigned int listtype)
1333 struct audit_entry *e;
1334 int ret = 1; /* Audit by default */
1337 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1340 for (i = 0; i < e->rule.field_count; i++) {
1341 struct audit_field *f = &e->rule.fields[i];
1347 pid = task_pid_nr(current);
1348 result = audit_comparator(pid, f->op, f->val);
1351 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1354 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1356 case AUDIT_LOGINUID:
1357 result = audit_uid_comparator(audit_get_loginuid(current),
1360 case AUDIT_LOGINUID_SET:
1361 result = audit_comparator(audit_loginuid_set(current),
1365 result = audit_comparator(msgtype, f->op, f->val);
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:
1373 security_task_getsecid(current, &sid);
1374 result = security_audit_rule_match(sid,
1375 f->type, f->op, f->lsm_rule);
1379 result = audit_exe_compare(current, e->rule.exe);
1380 if (f->op == Audit_not_equal)
1384 goto unlock_and_return;
1386 if (result < 0) /* error */
1387 goto unlock_and_return;
1392 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1402 static int update_lsm_rule(struct audit_krule *r)
1404 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1405 struct audit_entry *nentry;
1408 if (!security_audit_rule_known(r))
1411 nentry = audit_dupe_rule(r);
1412 if (entry->rule.exe)
1413 audit_remove_mark(entry->rule.exe);
1414 if (IS_ERR(nentry)) {
1415 /* save the first error encountered for the
1417 err = PTR_ERR(nentry);
1418 audit_panic("error updating LSM filters");
1420 list_del(&r->rlist);
1421 list_del_rcu(&entry->list);
1424 if (r->watch || r->tree)
1425 list_replace_init(&r->rlist, &nentry->rule.rlist);
1426 list_replace_rcu(&entry->list, &nentry->list);
1427 list_replace(&r->list, &nentry->rule.list);
1429 call_rcu(&entry->rcu, audit_free_rule_rcu);
1434 /* This function will re-initialize the lsm_rule field of all applicable rules.
1435 * It will traverse the filter lists serarching for rules that contain LSM
1436 * specific filter fields. When such a rule is found, it is copied, the
1437 * LSM field is re-initialized, and the old rule is replaced with the
1439 int audit_update_lsm_rules(void)
1441 struct audit_krule *r, *n;
1444 /* audit_filter_mutex synchronizes the writers */
1445 mutex_lock(&audit_filter_mutex);
1447 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1448 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1449 int res = update_lsm_rule(r);
1454 mutex_unlock(&audit_filter_mutex);