1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* auditfilter.c -- filtering of audit events
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/kernel.h>
12 #include <linux/audit.h>
13 #include <linux/kthread.h>
14 #include <linux/mutex.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>
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.
38 /* Audit filter lists, defined in <linux/audit.h> */
39 struct 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
52 static 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]),
63 DEFINE_MUTEX(audit_filter_mutex);
65 static void audit_free_lsm_field(struct audit_field *f)
76 case AUDIT_OBJ_LEV_LOW:
77 case AUDIT_OBJ_LEV_HIGH:
79 security_audit_rule_free(f->lsm_rule);
83 static inline void audit_free_rule(struct audit_entry *e)
86 struct audit_krule *erule = &e->rule;
88 /* some rules don't have associated watches */
90 audit_put_watch(erule->watch);
92 for (i = 0; i < erule->field_count; i++)
93 audit_free_lsm_field(&erule->fields[i]);
95 kfree(erule->filterkey);
99 void audit_free_rule_rcu(struct rcu_head *head)
101 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
105 /* Initialize an audit filterlist entry. */
106 static inline struct audit_entry *audit_init_entry(u32 field_count)
108 struct audit_entry *entry;
109 struct audit_field *fields;
111 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
112 if (unlikely(!entry))
115 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
116 if (unlikely(!fields)) {
120 entry->rule.fields = fields;
125 /* Unpack a filter field's string representation from user-space
127 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
131 if (!*bufp || (len == 0) || (len > *remain))
132 return ERR_PTR(-EINVAL);
134 /* Of the currently implemented string fields, PATH_MAX
135 * defines the longest valid length.
138 return ERR_PTR(-ENAMETOOLONG);
140 str = kmalloc(len + 1, GFP_KERNEL);
142 return ERR_PTR(-ENOMEM);
144 memcpy(str, *bufp, len);
152 /* Translate an inode field to kernel representation. */
153 static inline int audit_to_inode(struct audit_krule *krule,
154 struct audit_field *f)
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))
166 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
168 int __init audit_register_class(int class, unsigned *list)
170 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
173 while (*list != ~0U) {
174 unsigned n = *list++;
175 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
179 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
181 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
189 int audit_match_class(int class, unsigned syscall)
191 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
193 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
195 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
198 #ifdef CONFIG_AUDITSYSCALL
199 static inline int audit_match_class_bits(int class, u32 *mask)
203 if (classes[class]) {
204 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
205 if (mask[i] & classes[class][i])
211 static int audit_match_signal(struct audit_entry *entry)
213 struct audit_field *arch = entry->rule.arch_f;
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,
220 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
224 switch (audit_classify_arch(arch->val)) {
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
228 case 1: /* 32bit on biarch */
229 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
237 /* Common user-space to kernel rule translation. */
238 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
241 struct audit_entry *entry;
245 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
249 #ifdef CONFIG_AUDITSYSCALL
250 case AUDIT_FILTER_ENTRY:
251 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
253 case AUDIT_FILTER_EXIT:
254 case AUDIT_FILTER_URING_EXIT:
255 case AUDIT_FILTER_TASK:
257 case AUDIT_FILTER_USER:
258 case AUDIT_FILTER_EXCLUDE:
259 case AUDIT_FILTER_FS:
262 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
263 pr_err("AUDIT_POSSIBLE is deprecated\n");
266 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
268 if (rule->field_count > AUDIT_MAX_FIELDS)
272 entry = audit_init_entry(rule->field_count);
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;
281 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
282 entry->rule.mask[i] = rule->mask[i];
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)];
289 if (!(*p & AUDIT_BIT(bit)))
291 *p &= ~AUDIT_BIT(bit);
295 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
296 entry->rule.mask[j] |= class[j];
306 static u32 audit_ops[] =
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,
318 static u32 audit_to_op(u32 op)
321 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
326 /* check if an audit field is valid */
327 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
331 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
332 entry->rule.listnr != AUDIT_FILTER_USER)
336 if (entry->rule.listnr != AUDIT_FILTER_FS)
340 if (entry->rule.listnr == AUDIT_FILTER_URING_EXIT)
345 switch (entry->rule.listnr) {
346 case AUDIT_FILTER_FS:
349 case AUDIT_FILTERKEY:
356 /* Check for valid field type and op */
362 case AUDIT_PERS: /* <uapi/linux/personality.h> */
364 /* all ops are valid */
384 case AUDIT_SESSIONID:
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)
394 case AUDIT_SUBJ_USER:
395 case AUDIT_SUBJ_ROLE:
396 case AUDIT_SUBJ_TYPE:
402 case AUDIT_FILTERKEY:
403 case AUDIT_LOGINUID_SET:
408 case AUDIT_FIELD_COMPARE:
410 /* only equal and not equal valid ops */
411 if (f->op != Audit_not_equal && f->op != Audit_equal)
415 /* field not recognized */
419 /* Check for select valid field values */
421 case AUDIT_LOGINUID_SET:
422 if ((f->val != 0) && (f->val != 1))
430 if (f->val & ~S_IFMT)
433 case AUDIT_FIELD_COMPARE:
434 if (f->val > AUDIT_MAX_FIELD_COMPARE)
437 case AUDIT_SADDR_FAM:
438 if (f->val >= AF_MAX)
448 /* Translate struct audit_rule_data to kernel's rule representation. */
449 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
453 struct audit_entry *entry;
455 size_t remain = datasz - sizeof(struct audit_rule_data);
458 struct audit_fsnotify_mark *audit_mark;
460 entry = audit_to_entry_common(data);
465 for (i = 0; i < data->field_count; i++) {
466 struct audit_field *f = &entry->rule.fields[i];
471 f->op = audit_to_op(data->fieldflags[i]);
472 if (f->op == Audit_bad)
475 f->type = data->fields[i];
476 f_val = data->values[i];
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;
482 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
485 err = audit_field_valid(entry, f);
497 f->uid = make_kuid(current_user_ns(), f_val);
498 if (!uid_valid(f->uid))
506 f->gid = make_kgid(current_user_ns(), f_val);
507 if (!gid_valid(f->gid))
512 entry->rule.arch_f = f;
514 case AUDIT_SUBJ_USER:
515 case AUDIT_SUBJ_ROLE:
516 case AUDIT_SUBJ_TYPE:
522 case AUDIT_OBJ_LEV_LOW:
523 case AUDIT_OBJ_LEV_HIGH:
524 str = audit_unpack_string(&bufp, &remain, f_val);
529 entry->rule.buflen += f_val;
531 err = security_audit_rule_init(f->type, f->op, str,
532 (void **)&f->lsm_rule);
533 /* Keep currently invalid fields around in case they
534 * become valid after a policy reload. */
535 if (err == -EINVAL) {
536 pr_warn("audit rule for LSM \'%s\' is invalid\n",
543 str = audit_unpack_string(&bufp, &remain, f_val);
548 err = audit_to_watch(&entry->rule, str, f_val, f->op);
553 entry->rule.buflen += f_val;
556 str = audit_unpack_string(&bufp, &remain, f_val);
561 err = audit_make_tree(&entry->rule, str, f->op);
565 entry->rule.buflen += f_val;
569 err = audit_to_inode(&entry->rule, f);
573 case AUDIT_FILTERKEY:
574 if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
576 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 audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
593 if (IS_ERR(audit_mark)) {
595 err = PTR_ERR(audit_mark);
598 entry->rule.buflen += f_val;
599 entry->rule.exe = audit_mark;
607 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
608 entry->rule.inode_f = NULL;
614 if (entry->rule.tree)
615 audit_put_tree(entry->rule.tree); /* that's the temporary one */
617 audit_remove_mark(entry->rule.exe); /* that's the template one */
618 audit_free_rule(entry);
622 /* Pack a filter field's string representation into data block. */
623 static inline size_t audit_pack_string(void **bufp, const char *str)
625 size_t len = strlen(str);
627 memcpy(*bufp, str, len);
633 /* Translate kernel rule representation to struct audit_rule_data. */
634 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
636 struct audit_rule_data *data;
640 data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL);
643 memset(data, 0, sizeof(*data));
645 data->flags = krule->flags | krule->listnr;
646 data->action = krule->action;
647 data->field_count = krule->field_count;
649 for (i = 0; i < data->field_count; i++) {
650 struct audit_field *f = &krule->fields[i];
652 data->fields[i] = f->type;
653 data->fieldflags[i] = audit_ops[f->op];
655 case AUDIT_SUBJ_USER:
656 case AUDIT_SUBJ_ROLE:
657 case AUDIT_SUBJ_TYPE:
663 case AUDIT_OBJ_LEV_LOW:
664 case AUDIT_OBJ_LEV_HIGH:
665 data->buflen += data->values[i] =
666 audit_pack_string(&bufp, f->lsm_str);
669 data->buflen += data->values[i] =
670 audit_pack_string(&bufp,
671 audit_watch_path(krule->watch));
674 data->buflen += data->values[i] =
675 audit_pack_string(&bufp,
676 audit_tree_path(krule->tree));
678 case AUDIT_FILTERKEY:
679 data->buflen += data->values[i] =
680 audit_pack_string(&bufp, krule->filterkey);
683 data->buflen += data->values[i] =
684 audit_pack_string(&bufp, audit_mark_path(krule->exe));
686 case AUDIT_LOGINUID_SET:
687 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
688 data->fields[i] = AUDIT_LOGINUID;
689 data->values[i] = AUDIT_UID_UNSET;
692 fallthrough; /* if set */
694 data->values[i] = f->val;
697 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
698 data->mask[i] = krule->mask[i];
703 /* Compare two rules in kernel format. Considered success if rules
705 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
709 if (a->flags != b->flags ||
710 a->pflags != b->pflags ||
711 a->listnr != b->listnr ||
712 a->action != b->action ||
713 a->field_count != b->field_count)
716 for (i = 0; i < a->field_count; i++) {
717 if (a->fields[i].type != b->fields[i].type ||
718 a->fields[i].op != b->fields[i].op)
721 switch (a->fields[i].type) {
722 case AUDIT_SUBJ_USER:
723 case AUDIT_SUBJ_ROLE:
724 case AUDIT_SUBJ_TYPE:
730 case AUDIT_OBJ_LEV_LOW:
731 case AUDIT_OBJ_LEV_HIGH:
732 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
736 if (strcmp(audit_watch_path(a->watch),
737 audit_watch_path(b->watch)))
741 if (strcmp(audit_tree_path(a->tree),
742 audit_tree_path(b->tree)))
745 case AUDIT_FILTERKEY:
746 /* both filterkeys exist based on above type compare */
747 if (strcmp(a->filterkey, b->filterkey))
751 /* both paths exist based on above type compare */
752 if (strcmp(audit_mark_path(a->exe),
753 audit_mark_path(b->exe)))
762 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
770 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
774 if (a->fields[i].val != b->fields[i].val)
779 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
780 if (a->mask[i] != b->mask[i])
786 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
788 static inline int audit_dupe_lsm_field(struct audit_field *df,
789 struct audit_field *sf)
794 /* our own copy of lsm_str */
795 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
796 if (unlikely(!lsm_str))
798 df->lsm_str = lsm_str;
800 /* our own (refreshed) copy of lsm_rule */
801 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
802 (void **)&df->lsm_rule);
803 /* Keep currently invalid fields around in case they
804 * become valid after a policy reload. */
805 if (ret == -EINVAL) {
806 pr_warn("audit rule for LSM \'%s\' is invalid\n",
814 /* Duplicate an audit rule. This will be a deep copy with the exception
815 * of the watch - that pointer is carried over. The LSM specific fields
816 * will be updated in the copy. The point is to be able to replace the old
817 * rule with the new rule in the filterlist, then free the old rule.
818 * The rlist element is undefined; list manipulations are handled apart from
819 * the initial copy. */
820 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
822 u32 fcount = old->field_count;
823 struct audit_entry *entry;
824 struct audit_krule *new;
828 entry = audit_init_entry(fcount);
829 if (unlikely(!entry))
830 return ERR_PTR(-ENOMEM);
833 new->flags = old->flags;
834 new->pflags = old->pflags;
835 new->listnr = old->listnr;
836 new->action = old->action;
837 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
838 new->mask[i] = old->mask[i];
839 new->prio = old->prio;
840 new->buflen = old->buflen;
841 new->inode_f = old->inode_f;
842 new->field_count = old->field_count;
845 * note that we are OK with not refcounting here; audit_match_tree()
846 * never dereferences tree and we can't get false positives there
847 * since we'd have to have rule gone from the list *and* removed
848 * before the chunks found by lookup had been allocated, i.e. before
849 * the beginning of list scan.
851 new->tree = old->tree;
852 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
854 /* deep copy this information, updating the lsm_rule fields, because
855 * the originals will all be freed when the old rule is freed. */
856 for (i = 0; i < fcount; i++) {
857 switch (new->fields[i].type) {
858 case AUDIT_SUBJ_USER:
859 case AUDIT_SUBJ_ROLE:
860 case AUDIT_SUBJ_TYPE:
866 case AUDIT_OBJ_LEV_LOW:
867 case AUDIT_OBJ_LEV_HIGH:
868 err = audit_dupe_lsm_field(&new->fields[i],
871 case AUDIT_FILTERKEY:
872 fk = kstrdup(old->filterkey, GFP_KERNEL);
879 err = audit_dupe_exe(new, old);
884 audit_remove_mark(new->exe);
885 audit_free_rule(entry);
891 audit_get_watch(old->watch);
892 new->watch = old->watch;
898 /* Find an existing audit rule.
899 * Caller must hold audit_filter_mutex to prevent stale rule data. */
900 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
901 struct list_head **p)
903 struct audit_entry *e, *found = NULL;
904 struct list_head *list;
907 if (entry->rule.inode_f) {
908 h = audit_hash_ino(entry->rule.inode_f->val);
909 *p = list = &audit_inode_hash[h];
910 } else if (entry->rule.watch) {
911 /* we don't know the inode number, so must walk entire hash */
912 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
913 list = &audit_inode_hash[h];
914 list_for_each_entry(e, list, list)
915 if (!audit_compare_rule(&entry->rule, &e->rule)) {
922 *p = list = &audit_filter_list[entry->rule.listnr];
925 list_for_each_entry(e, list, list)
926 if (!audit_compare_rule(&entry->rule, &e->rule)) {
935 static u64 prio_low = ~0ULL/2;
936 static u64 prio_high = ~0ULL/2 - 1;
938 /* Add rule to given filterlist if not a duplicate. */
939 static inline int audit_add_rule(struct audit_entry *entry)
941 struct audit_entry *e;
942 struct audit_watch *watch = entry->rule.watch;
943 struct audit_tree *tree = entry->rule.tree;
944 struct list_head *list;
946 #ifdef CONFIG_AUDITSYSCALL
949 /* If any of these, don't count towards total */
950 switch (entry->rule.listnr) {
951 case AUDIT_FILTER_USER:
952 case AUDIT_FILTER_EXCLUDE:
953 case AUDIT_FILTER_FS:
958 mutex_lock(&audit_filter_mutex);
959 e = audit_find_rule(entry, &list);
961 mutex_unlock(&audit_filter_mutex);
963 /* normally audit_add_tree_rule() will free it on failure */
965 audit_put_tree(tree);
970 /* audit_filter_mutex is dropped and re-taken during this call */
971 err = audit_add_watch(&entry->rule, &list);
973 mutex_unlock(&audit_filter_mutex);
975 * normally audit_add_tree_rule() will free it
979 audit_put_tree(tree);
984 err = audit_add_tree_rule(&entry->rule);
986 mutex_unlock(&audit_filter_mutex);
991 entry->rule.prio = ~0ULL;
992 if (entry->rule.listnr == AUDIT_FILTER_EXIT ||
993 entry->rule.listnr == AUDIT_FILTER_URING_EXIT) {
994 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
995 entry->rule.prio = ++prio_high;
997 entry->rule.prio = --prio_low;
1000 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1001 list_add(&entry->rule.list,
1002 &audit_rules_list[entry->rule.listnr]);
1003 list_add_rcu(&entry->list, list);
1004 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1006 list_add_tail(&entry->rule.list,
1007 &audit_rules_list[entry->rule.listnr]);
1008 list_add_tail_rcu(&entry->list, list);
1010 #ifdef CONFIG_AUDITSYSCALL
1014 if (!audit_match_signal(entry))
1017 mutex_unlock(&audit_filter_mutex);
1022 /* Remove an existing rule from filterlist. */
1023 int audit_del_rule(struct audit_entry *entry)
1025 struct audit_entry *e;
1026 struct audit_tree *tree = entry->rule.tree;
1027 struct list_head *list;
1029 #ifdef CONFIG_AUDITSYSCALL
1032 /* If any of these, don't count towards total */
1033 switch (entry->rule.listnr) {
1034 case AUDIT_FILTER_USER:
1035 case AUDIT_FILTER_EXCLUDE:
1036 case AUDIT_FILTER_FS:
1041 mutex_lock(&audit_filter_mutex);
1042 e = audit_find_rule(entry, &list);
1049 audit_remove_watch_rule(&e->rule);
1052 audit_remove_tree_rule(&e->rule);
1055 audit_remove_mark_rule(&e->rule);
1057 #ifdef CONFIG_AUDITSYSCALL
1061 if (!audit_match_signal(entry))
1065 list_del_rcu(&e->list);
1066 list_del(&e->rule.list);
1067 call_rcu(&e->rcu, audit_free_rule_rcu);
1070 mutex_unlock(&audit_filter_mutex);
1073 audit_put_tree(tree); /* that's the temporary one */
1078 /* List rules using struct audit_rule_data. */
1079 static void audit_list_rules(int seq, struct sk_buff_head *q)
1081 struct sk_buff *skb;
1082 struct audit_krule *r;
1085 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1086 * iterator to sync with list writers. */
1087 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1088 list_for_each_entry(r, &audit_rules_list[i], list) {
1089 struct audit_rule_data *data;
1091 data = audit_krule_to_data(r);
1092 if (unlikely(!data))
1094 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1096 struct_size(data, buf, data->buflen));
1098 skb_queue_tail(q, skb);
1102 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1104 skb_queue_tail(q, skb);
1107 /* Log rule additions and removals */
1108 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1110 struct audit_buffer *ab;
1115 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1118 audit_log_session_info(ab);
1119 audit_log_task_context(ab);
1120 audit_log_format(ab, " op=%s", action);
1121 audit_log_key(ab, rule->filterkey);
1122 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1127 * audit_rule_change - apply all rules to the specified message type
1128 * @type: audit message type
1129 * @seq: netlink audit message sequence (serial) number
1130 * @data: payload data
1131 * @datasz: size of payload data
1133 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1136 struct audit_entry *entry;
1139 case AUDIT_ADD_RULE:
1140 entry = audit_data_to_entry(data, datasz);
1142 return PTR_ERR(entry);
1143 err = audit_add_rule(entry);
1144 audit_log_rule_change("add_rule", &entry->rule, !err);
1146 case AUDIT_DEL_RULE:
1147 entry = audit_data_to_entry(data, datasz);
1149 return PTR_ERR(entry);
1150 err = audit_del_rule(entry);
1151 audit_log_rule_change("remove_rule", &entry->rule, !err);
1158 if (err || type == AUDIT_DEL_RULE) {
1159 if (entry->rule.exe)
1160 audit_remove_mark(entry->rule.exe);
1161 audit_free_rule(entry);
1168 * audit_list_rules_send - list the audit rules
1169 * @request_skb: skb of request we are replying to (used to target the reply)
1170 * @seq: netlink audit message sequence (serial) number
1172 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1174 struct task_struct *tsk;
1175 struct audit_netlink_list *dest;
1177 /* We can't just spew out the rules here because we might fill
1178 * the available socket buffer space and deadlock waiting for
1179 * auditctl to read from it... which isn't ever going to
1180 * happen if we're actually running in the context of auditctl
1181 * trying to _send_ the stuff */
1183 dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1186 dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1187 dest->portid = NETLINK_CB(request_skb).portid;
1188 skb_queue_head_init(&dest->q);
1190 mutex_lock(&audit_filter_mutex);
1191 audit_list_rules(seq, &dest->q);
1192 mutex_unlock(&audit_filter_mutex);
1194 tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1196 skb_queue_purge(&dest->q);
1199 return PTR_ERR(tsk);
1205 int audit_comparator(u32 left, u32 op, u32 right)
1209 return (left == right);
1210 case Audit_not_equal:
1211 return (left != right);
1213 return (left < right);
1215 return (left <= right);
1217 return (left > right);
1219 return (left >= right);
1221 return (left & right);
1223 return ((left & right) == right);
1229 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1233 return uid_eq(left, right);
1234 case Audit_not_equal:
1235 return !uid_eq(left, right);
1237 return uid_lt(left, right);
1239 return uid_lte(left, right);
1241 return uid_gt(left, right);
1243 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);
1274 * parent_len - find the length of the parent portion of a pathname
1275 * @path: pathname of which to determine length
1277 int parent_len(const char *path)
1282 plen = strlen(path);
1287 /* disregard trailing slashes */
1288 p = path + plen - 1;
1289 while ((*p == '/') && (p > path))
1292 /* walk backward until we find the next slash or hit beginning */
1293 while ((*p != '/') && (p > path))
1296 /* did we find a slash? Then increment to include it in path */
1304 * audit_compare_dname_path - compare given dentry name with last component in
1305 * given path. Return of 0 indicates a match.
1306 * @dname: dentry name that we're comparing
1307 * @path: full pathname that we're comparing
1308 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1309 * here indicates that we must compute this value.
1311 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1317 pathlen = strlen(path);
1321 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1322 if (pathlen - parentlen != dlen)
1325 p = path + parentlen;
1327 return strncmp(p, dname->name, dlen);
1330 int audit_filter(int msgtype, unsigned int listtype)
1332 struct audit_entry *e;
1333 int ret = 1; /* Audit by default */
1336 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1339 for (i = 0; i < e->rule.field_count; i++) {
1340 struct audit_field *f = &e->rule.fields[i];
1346 pid = task_pid_nr(current);
1347 result = audit_comparator(pid, f->op, f->val);
1350 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1353 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1355 case AUDIT_LOGINUID:
1356 result = audit_uid_comparator(audit_get_loginuid(current),
1359 case AUDIT_LOGINUID_SET:
1360 result = audit_comparator(audit_loginuid_set(current),
1364 result = audit_comparator(msgtype, f->op, f->val);
1366 case AUDIT_SUBJ_USER:
1367 case AUDIT_SUBJ_ROLE:
1368 case AUDIT_SUBJ_TYPE:
1369 case AUDIT_SUBJ_SEN:
1370 case AUDIT_SUBJ_CLR:
1372 security_current_getsecid_subj(&sid);
1373 result = security_audit_rule_match(sid,
1374 f->type, f->op, f->lsm_rule);
1378 result = audit_exe_compare(current, e->rule.exe);
1379 if (f->op == Audit_not_equal)
1383 goto unlock_and_return;
1385 if (result < 0) /* error */
1386 goto unlock_and_return;
1391 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1401 static int update_lsm_rule(struct audit_krule *r)
1403 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1404 struct audit_entry *nentry;
1407 if (!security_audit_rule_known(r))
1410 nentry = audit_dupe_rule(r);
1411 if (entry->rule.exe)
1412 audit_remove_mark(entry->rule.exe);
1413 if (IS_ERR(nentry)) {
1414 /* save the first error encountered for the
1416 err = PTR_ERR(nentry);
1417 audit_panic("error updating LSM filters");
1419 list_del(&r->rlist);
1420 list_del_rcu(&entry->list);
1423 if (r->watch || r->tree)
1424 list_replace_init(&r->rlist, &nentry->rule.rlist);
1425 list_replace_rcu(&entry->list, &nentry->list);
1426 list_replace(&r->list, &nentry->rule.list);
1428 call_rcu(&entry->rcu, audit_free_rule_rcu);
1433 /* This function will re-initialize the lsm_rule field of all applicable rules.
1434 * It will traverse the filter lists serarching for rules that contain LSM
1435 * specific filter fields. When such a rule is found, it is copied, the
1436 * LSM field is re-initialized, and the old rule is replaced with the
1438 int audit_update_lsm_rules(void)
1440 struct audit_krule *r, *n;
1443 /* audit_filter_mutex synchronizes the writers */
1444 mutex_lock(&audit_filter_mutex);
1446 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1447 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1448 int res = update_lsm_rule(r);
1453 mutex_unlock(&audit_filter_mutex);