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 #if AUDIT_NR_FILTERS != 7
48 #error Fix audit_filter_list initialiser
51 static 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]),
61 DEFINE_MUTEX(audit_filter_mutex);
63 static void audit_free_lsm_field(struct audit_field *f)
74 case AUDIT_OBJ_LEV_LOW:
75 case AUDIT_OBJ_LEV_HIGH:
77 security_audit_rule_free(f->lsm_rule);
81 static inline void audit_free_rule(struct audit_entry *e)
84 struct audit_krule *erule = &e->rule;
86 /* some rules don't have associated watches */
88 audit_put_watch(erule->watch);
90 for (i = 0; i < erule->field_count; i++)
91 audit_free_lsm_field(&erule->fields[i]);
93 kfree(erule->filterkey);
97 void audit_free_rule_rcu(struct rcu_head *head)
99 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
103 /* Initialize an audit filterlist entry. */
104 static inline struct audit_entry *audit_init_entry(u32 field_count)
106 struct audit_entry *entry;
107 struct audit_field *fields;
109 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
110 if (unlikely(!entry))
113 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
114 if (unlikely(!fields)) {
118 entry->rule.fields = fields;
123 /* Unpack a filter field's string representation from user-space
125 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
129 if (!*bufp || (len == 0) || (len > *remain))
130 return ERR_PTR(-EINVAL);
132 /* Of the currently implemented string fields, PATH_MAX
133 * defines the longest valid length.
136 return ERR_PTR(-ENAMETOOLONG);
138 str = kmalloc(len + 1, GFP_KERNEL);
140 return ERR_PTR(-ENOMEM);
142 memcpy(str, *bufp, len);
150 /* Translate an inode field to kernel representation. */
151 static inline int audit_to_inode(struct audit_krule *krule,
152 struct audit_field *f)
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))
163 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
165 int __init audit_register_class(int class, unsigned *list)
167 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
170 while (*list != ~0U) {
171 unsigned n = *list++;
172 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
176 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
178 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
186 int audit_match_class(int class, unsigned syscall)
188 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
190 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
192 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
195 #ifdef CONFIG_AUDITSYSCALL
196 static inline int audit_match_class_bits(int class, u32 *mask)
200 if (classes[class]) {
201 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
202 if (mask[i] & classes[class][i])
208 static int audit_match_signal(struct audit_entry *entry)
210 struct audit_field *arch = entry->rule.arch_f;
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,
217 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
221 switch(audit_classify_arch(arch->val)) {
223 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
225 case 1: /* 32bit on biarch */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
234 /* Common user-space to kernel rule translation. */
235 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
238 struct audit_entry *entry;
242 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
246 #ifdef CONFIG_AUDITSYSCALL
247 case AUDIT_FILTER_ENTRY:
248 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
250 case AUDIT_FILTER_EXIT:
251 case AUDIT_FILTER_TASK:
253 case AUDIT_FILTER_USER:
254 case AUDIT_FILTER_EXCLUDE:
255 case AUDIT_FILTER_FS:
258 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
259 pr_err("AUDIT_POSSIBLE is deprecated\n");
262 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
264 if (rule->field_count > AUDIT_MAX_FIELDS)
268 entry = audit_init_entry(rule->field_count);
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;
277 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
278 entry->rule.mask[i] = rule->mask[i];
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)];
285 if (!(*p & AUDIT_BIT(bit)))
287 *p &= ~AUDIT_BIT(bit);
291 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
292 entry->rule.mask[j] |= class[j];
302 static u32 audit_ops[] =
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,
314 static u32 audit_to_op(u32 op)
317 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
322 /* check if an audit field is valid */
323 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
327 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
328 entry->rule.listnr != AUDIT_FILTER_USER)
332 if (entry->rule.listnr != AUDIT_FILTER_FS)
337 switch(entry->rule.listnr) {
338 case AUDIT_FILTER_FS:
341 case AUDIT_FILTERKEY:
371 case AUDIT_SESSIONID:
372 /* bit ops are only useful on syscall args */
373 if (f->op == Audit_bitmask || f->op == Audit_bittest)
380 case AUDIT_SUBJ_USER:
381 case AUDIT_SUBJ_ROLE:
382 case AUDIT_SUBJ_TYPE:
388 case AUDIT_OBJ_LEV_LOW:
389 case AUDIT_OBJ_LEV_HIGH:
392 case AUDIT_FILTERKEY:
394 case AUDIT_LOGINUID_SET:
395 if ((f->val != 0) && (f->val != 1))
400 if (f->op != Audit_not_equal && f->op != Audit_equal)
408 if (f->val & ~S_IFMT)
411 case AUDIT_FIELD_COMPARE:
412 if (f->val > AUDIT_MAX_FIELD_COMPARE)
416 if (f->op != Audit_not_equal && f->op != Audit_equal)
423 /* Translate struct audit_rule_data to kernel's rule representation. */
424 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
428 struct audit_entry *entry;
430 size_t remain = datasz - sizeof(struct audit_rule_data);
433 struct audit_fsnotify_mark *audit_mark;
435 entry = audit_to_entry_common(data);
440 for (i = 0; i < data->field_count; i++) {
441 struct audit_field *f = &entry->rule.fields[i];
445 f->op = audit_to_op(data->fieldflags[i]);
446 if (f->op == Audit_bad)
449 f->type = data->fields[i];
450 f->val = data->values[i];
452 /* Support legacy tests for a valid loginuid */
453 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
454 f->type = AUDIT_LOGINUID_SET;
456 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
459 err = audit_field_valid(entry, f);
471 f->uid = make_kuid(current_user_ns(), f->val);
472 if (!uid_valid(f->uid))
480 f->gid = make_kgid(current_user_ns(), f->val);
481 if (!gid_valid(f->gid))
485 entry->rule.arch_f = f;
487 case AUDIT_SUBJ_USER:
488 case AUDIT_SUBJ_ROLE:
489 case AUDIT_SUBJ_TYPE:
495 case AUDIT_OBJ_LEV_LOW:
496 case AUDIT_OBJ_LEV_HIGH:
497 str = audit_unpack_string(&bufp, &remain, f->val);
500 entry->rule.buflen += f->val;
502 err = security_audit_rule_init(f->type, f->op, str,
503 (void **)&f->lsm_rule);
504 /* Keep currently invalid fields around in case they
505 * become valid after a policy reload. */
506 if (err == -EINVAL) {
507 pr_warn("audit rule for LSM \'%s\' is invalid\n",
518 str = audit_unpack_string(&bufp, &remain, f->val);
521 entry->rule.buflen += f->val;
523 err = audit_to_watch(&entry->rule, str, f->val, f->op);
530 str = audit_unpack_string(&bufp, &remain, f->val);
533 entry->rule.buflen += f->val;
535 err = audit_make_tree(&entry->rule, str, f->op);
541 err = audit_to_inode(&entry->rule, f);
545 case AUDIT_FILTERKEY:
546 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
548 str = audit_unpack_string(&bufp, &remain, f->val);
551 entry->rule.buflen += f->val;
552 entry->rule.filterkey = str;
555 if (entry->rule.exe || f->val > PATH_MAX)
557 str = audit_unpack_string(&bufp, &remain, f->val);
562 entry->rule.buflen += f->val;
564 audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
565 if (IS_ERR(audit_mark)) {
567 err = PTR_ERR(audit_mark);
570 entry->rule.exe = audit_mark;
575 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
576 entry->rule.inode_f = NULL;
582 if (entry->rule.tree)
583 audit_put_tree(entry->rule.tree); /* that's the temporary one */
585 audit_remove_mark(entry->rule.exe); /* that's the template one */
586 audit_free_rule(entry);
590 /* Pack a filter field's string representation into data block. */
591 static inline size_t audit_pack_string(void **bufp, const char *str)
593 size_t len = strlen(str);
595 memcpy(*bufp, str, len);
601 /* Translate kernel rule representation to struct audit_rule_data. */
602 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
604 struct audit_rule_data *data;
608 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
611 memset(data, 0, sizeof(*data));
613 data->flags = krule->flags | krule->listnr;
614 data->action = krule->action;
615 data->field_count = krule->field_count;
617 for (i = 0; i < data->field_count; i++) {
618 struct audit_field *f = &krule->fields[i];
620 data->fields[i] = f->type;
621 data->fieldflags[i] = audit_ops[f->op];
623 case AUDIT_SUBJ_USER:
624 case AUDIT_SUBJ_ROLE:
625 case AUDIT_SUBJ_TYPE:
631 case AUDIT_OBJ_LEV_LOW:
632 case AUDIT_OBJ_LEV_HIGH:
633 data->buflen += data->values[i] =
634 audit_pack_string(&bufp, f->lsm_str);
637 data->buflen += data->values[i] =
638 audit_pack_string(&bufp,
639 audit_watch_path(krule->watch));
642 data->buflen += data->values[i] =
643 audit_pack_string(&bufp,
644 audit_tree_path(krule->tree));
646 case AUDIT_FILTERKEY:
647 data->buflen += data->values[i] =
648 audit_pack_string(&bufp, krule->filterkey);
651 data->buflen += data->values[i] =
652 audit_pack_string(&bufp, audit_mark_path(krule->exe));
654 case AUDIT_LOGINUID_SET:
655 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
656 data->fields[i] = AUDIT_LOGINUID;
657 data->values[i] = AUDIT_UID_UNSET;
660 /* fall through - if set */
662 data->values[i] = f->val;
665 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
670 /* Compare two rules in kernel format. Considered success if rules
672 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
676 if (a->flags != b->flags ||
677 a->pflags != b->pflags ||
678 a->listnr != b->listnr ||
679 a->action != b->action ||
680 a->field_count != b->field_count)
683 for (i = 0; i < a->field_count; i++) {
684 if (a->fields[i].type != b->fields[i].type ||
685 a->fields[i].op != b->fields[i].op)
688 switch(a->fields[i].type) {
689 case AUDIT_SUBJ_USER:
690 case AUDIT_SUBJ_ROLE:
691 case AUDIT_SUBJ_TYPE:
697 case AUDIT_OBJ_LEV_LOW:
698 case AUDIT_OBJ_LEV_HIGH:
699 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
703 if (strcmp(audit_watch_path(a->watch),
704 audit_watch_path(b->watch)))
708 if (strcmp(audit_tree_path(a->tree),
709 audit_tree_path(b->tree)))
712 case AUDIT_FILTERKEY:
713 /* both filterkeys exist based on above type compare */
714 if (strcmp(a->filterkey, b->filterkey))
718 /* both paths exist based on above type compare */
719 if (strcmp(audit_mark_path(a->exe),
720 audit_mark_path(b->exe)))
729 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
737 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
741 if (a->fields[i].val != b->fields[i].val)
746 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
747 if (a->mask[i] != b->mask[i])
753 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
755 static inline int audit_dupe_lsm_field(struct audit_field *df,
756 struct audit_field *sf)
761 /* our own copy of lsm_str */
762 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
763 if (unlikely(!lsm_str))
765 df->lsm_str = lsm_str;
767 /* our own (refreshed) copy of lsm_rule */
768 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
769 (void **)&df->lsm_rule);
770 /* Keep currently invalid fields around in case they
771 * become valid after a policy reload. */
772 if (ret == -EINVAL) {
773 pr_warn("audit rule for LSM \'%s\' is invalid\n",
781 /* Duplicate an audit rule. This will be a deep copy with the exception
782 * of the watch - that pointer is carried over. The LSM specific fields
783 * will be updated in the copy. The point is to be able to replace the old
784 * rule with the new rule in the filterlist, then free the old rule.
785 * The rlist element is undefined; list manipulations are handled apart from
786 * the initial copy. */
787 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
789 u32 fcount = old->field_count;
790 struct audit_entry *entry;
791 struct audit_krule *new;
795 entry = audit_init_entry(fcount);
796 if (unlikely(!entry))
797 return ERR_PTR(-ENOMEM);
800 new->flags = old->flags;
801 new->pflags = old->pflags;
802 new->listnr = old->listnr;
803 new->action = old->action;
804 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
805 new->mask[i] = old->mask[i];
806 new->prio = old->prio;
807 new->buflen = old->buflen;
808 new->inode_f = old->inode_f;
809 new->field_count = old->field_count;
812 * note that we are OK with not refcounting here; audit_match_tree()
813 * never dereferences tree and we can't get false positives there
814 * since we'd have to have rule gone from the list *and* removed
815 * before the chunks found by lookup had been allocated, i.e. before
816 * the beginning of list scan.
818 new->tree = old->tree;
819 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
821 /* deep copy this information, updating the lsm_rule fields, because
822 * the originals will all be freed when the old rule is freed. */
823 for (i = 0; i < fcount; i++) {
824 switch (new->fields[i].type) {
825 case AUDIT_SUBJ_USER:
826 case AUDIT_SUBJ_ROLE:
827 case AUDIT_SUBJ_TYPE:
833 case AUDIT_OBJ_LEV_LOW:
834 case AUDIT_OBJ_LEV_HIGH:
835 err = audit_dupe_lsm_field(&new->fields[i],
838 case AUDIT_FILTERKEY:
839 fk = kstrdup(old->filterkey, GFP_KERNEL);
846 err = audit_dupe_exe(new, old);
851 audit_remove_mark(new->exe);
852 audit_free_rule(entry);
858 audit_get_watch(old->watch);
859 new->watch = old->watch;
865 /* Find an existing audit rule.
866 * Caller must hold audit_filter_mutex to prevent stale rule data. */
867 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
868 struct list_head **p)
870 struct audit_entry *e, *found = NULL;
871 struct list_head *list;
874 if (entry->rule.inode_f) {
875 h = audit_hash_ino(entry->rule.inode_f->val);
876 *p = list = &audit_inode_hash[h];
877 } else if (entry->rule.watch) {
878 /* we don't know the inode number, so must walk entire hash */
879 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
880 list = &audit_inode_hash[h];
881 list_for_each_entry(e, list, list)
882 if (!audit_compare_rule(&entry->rule, &e->rule)) {
889 *p = list = &audit_filter_list[entry->rule.listnr];
892 list_for_each_entry(e, list, list)
893 if (!audit_compare_rule(&entry->rule, &e->rule)) {
902 static u64 prio_low = ~0ULL/2;
903 static u64 prio_high = ~0ULL/2 - 1;
905 /* Add rule to given filterlist if not a duplicate. */
906 static inline int audit_add_rule(struct audit_entry *entry)
908 struct audit_entry *e;
909 struct audit_watch *watch = entry->rule.watch;
910 struct audit_tree *tree = entry->rule.tree;
911 struct list_head *list;
913 #ifdef CONFIG_AUDITSYSCALL
916 /* If any of these, don't count towards total */
917 switch(entry->rule.listnr) {
918 case AUDIT_FILTER_USER:
919 case AUDIT_FILTER_EXCLUDE:
920 case AUDIT_FILTER_FS:
925 mutex_lock(&audit_filter_mutex);
926 e = audit_find_rule(entry, &list);
928 mutex_unlock(&audit_filter_mutex);
930 /* normally audit_add_tree_rule() will free it on failure */
932 audit_put_tree(tree);
937 /* audit_filter_mutex is dropped and re-taken during this call */
938 err = audit_add_watch(&entry->rule, &list);
940 mutex_unlock(&audit_filter_mutex);
942 * normally audit_add_tree_rule() will free it
946 audit_put_tree(tree);
951 err = audit_add_tree_rule(&entry->rule);
953 mutex_unlock(&audit_filter_mutex);
958 entry->rule.prio = ~0ULL;
959 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
960 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
961 entry->rule.prio = ++prio_high;
963 entry->rule.prio = --prio_low;
966 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
967 list_add(&entry->rule.list,
968 &audit_rules_list[entry->rule.listnr]);
969 list_add_rcu(&entry->list, list);
970 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
972 list_add_tail(&entry->rule.list,
973 &audit_rules_list[entry->rule.listnr]);
974 list_add_tail_rcu(&entry->list, list);
976 #ifdef CONFIG_AUDITSYSCALL
980 if (!audit_match_signal(entry))
983 mutex_unlock(&audit_filter_mutex);
988 /* Remove an existing rule from filterlist. */
989 int audit_del_rule(struct audit_entry *entry)
991 struct audit_entry *e;
992 struct audit_tree *tree = entry->rule.tree;
993 struct list_head *list;
995 #ifdef CONFIG_AUDITSYSCALL
998 /* If any of these, don't count towards total */
999 switch(entry->rule.listnr) {
1000 case AUDIT_FILTER_USER:
1001 case AUDIT_FILTER_EXCLUDE:
1002 case AUDIT_FILTER_FS:
1007 mutex_lock(&audit_filter_mutex);
1008 e = audit_find_rule(entry, &list);
1015 audit_remove_watch_rule(&e->rule);
1018 audit_remove_tree_rule(&e->rule);
1021 audit_remove_mark_rule(&e->rule);
1023 #ifdef CONFIG_AUDITSYSCALL
1027 if (!audit_match_signal(entry))
1031 list_del_rcu(&e->list);
1032 list_del(&e->rule.list);
1033 call_rcu(&e->rcu, audit_free_rule_rcu);
1036 mutex_unlock(&audit_filter_mutex);
1039 audit_put_tree(tree); /* that's the temporary one */
1044 /* List rules using struct audit_rule_data. */
1045 static void audit_list_rules(int seq, struct sk_buff_head *q)
1047 struct sk_buff *skb;
1048 struct audit_krule *r;
1051 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1052 * iterator to sync with list writers. */
1053 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1054 list_for_each_entry(r, &audit_rules_list[i], list) {
1055 struct audit_rule_data *data;
1057 data = audit_krule_to_data(r);
1058 if (unlikely(!data))
1060 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1062 sizeof(*data) + data->buflen);
1064 skb_queue_tail(q, skb);
1068 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1070 skb_queue_tail(q, skb);
1073 /* Log rule additions and removals */
1074 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1076 struct audit_buffer *ab;
1081 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1084 audit_log_session_info(ab);
1085 audit_log_task_context(ab);
1086 audit_log_format(ab, " op=%s", action);
1087 audit_log_key(ab, rule->filterkey);
1088 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1093 * audit_rule_change - apply all rules to the specified message type
1094 * @type: audit message type
1095 * @seq: netlink audit message sequence (serial) number
1096 * @data: payload data
1097 * @datasz: size of payload data
1099 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1102 struct audit_entry *entry;
1105 case AUDIT_ADD_RULE:
1106 entry = audit_data_to_entry(data, datasz);
1108 return PTR_ERR(entry);
1109 err = audit_add_rule(entry);
1110 audit_log_rule_change("add_rule", &entry->rule, !err);
1112 case AUDIT_DEL_RULE:
1113 entry = audit_data_to_entry(data, datasz);
1115 return PTR_ERR(entry);
1116 err = audit_del_rule(entry);
1117 audit_log_rule_change("remove_rule", &entry->rule, !err);
1124 if (err || type == AUDIT_DEL_RULE) {
1125 if (entry->rule.exe)
1126 audit_remove_mark(entry->rule.exe);
1127 audit_free_rule(entry);
1134 * audit_list_rules_send - list the audit rules
1135 * @request_skb: skb of request we are replying to (used to target the reply)
1136 * @seq: netlink audit message sequence (serial) number
1138 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1140 u32 portid = NETLINK_CB(request_skb).portid;
1141 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1142 struct task_struct *tsk;
1143 struct audit_netlink_list *dest;
1146 /* We can't just spew out the rules here because we might fill
1147 * the available socket buffer space and deadlock waiting for
1148 * auditctl to read from it... which isn't ever going to
1149 * happen if we're actually running in the context of auditctl
1150 * trying to _send_ the stuff */
1152 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1155 dest->net = get_net(net);
1156 dest->portid = portid;
1157 skb_queue_head_init(&dest->q);
1159 mutex_lock(&audit_filter_mutex);
1160 audit_list_rules(seq, &dest->q);
1161 mutex_unlock(&audit_filter_mutex);
1163 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1165 skb_queue_purge(&dest->q);
1173 int audit_comparator(u32 left, u32 op, u32 right)
1177 return (left == right);
1178 case Audit_not_equal:
1179 return (left != right);
1181 return (left < right);
1183 return (left <= right);
1185 return (left > right);
1187 return (left >= right);
1189 return (left & right);
1191 return ((left & right) == right);
1198 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1202 return uid_eq(left, right);
1203 case Audit_not_equal:
1204 return !uid_eq(left, right);
1206 return uid_lt(left, right);
1208 return uid_lte(left, right);
1210 return uid_gt(left, right);
1212 return uid_gte(left, right);
1221 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1225 return gid_eq(left, right);
1226 case Audit_not_equal:
1227 return !gid_eq(left, right);
1229 return gid_lt(left, right);
1231 return gid_lte(left, right);
1233 return gid_gt(left, right);
1235 return gid_gte(left, right);
1245 * parent_len - find the length of the parent portion of a pathname
1246 * @path: pathname of which to determine length
1248 int parent_len(const char *path)
1253 plen = strlen(path);
1258 /* disregard trailing slashes */
1259 p = path + plen - 1;
1260 while ((*p == '/') && (p > path))
1263 /* walk backward until we find the next slash or hit beginning */
1264 while ((*p != '/') && (p > path))
1267 /* did we find a slash? Then increment to include it in path */
1275 * audit_compare_dname_path - compare given dentry name with last component in
1276 * given path. Return of 0 indicates a match.
1277 * @dname: dentry name that we're comparing
1278 * @path: full pathname that we're comparing
1279 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1280 * here indicates that we must compute this value.
1282 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1288 pathlen = strlen(path);
1292 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1293 if (pathlen - parentlen != dlen)
1296 p = path + parentlen;
1298 return strncmp(p, dname->name, dlen);
1301 int audit_filter(int msgtype, unsigned int listtype)
1303 struct audit_entry *e;
1304 int ret = 1; /* Audit by default */
1307 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1310 for (i = 0; i < e->rule.field_count; i++) {
1311 struct audit_field *f = &e->rule.fields[i];
1317 pid = task_pid_nr(current);
1318 result = audit_comparator(pid, f->op, f->val);
1321 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1324 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1326 case AUDIT_LOGINUID:
1327 result = audit_uid_comparator(audit_get_loginuid(current),
1330 case AUDIT_LOGINUID_SET:
1331 result = audit_comparator(audit_loginuid_set(current),
1335 result = audit_comparator(msgtype, f->op, f->val);
1337 case AUDIT_SUBJ_USER:
1338 case AUDIT_SUBJ_ROLE:
1339 case AUDIT_SUBJ_TYPE:
1340 case AUDIT_SUBJ_SEN:
1341 case AUDIT_SUBJ_CLR:
1343 security_task_getsecid(current, &sid);
1344 result = security_audit_rule_match(sid,
1345 f->type, f->op, f->lsm_rule);
1349 result = audit_exe_compare(current, e->rule.exe);
1350 if (f->op == Audit_not_equal)
1354 goto unlock_and_return;
1356 if (result < 0) /* error */
1357 goto unlock_and_return;
1362 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1372 static int update_lsm_rule(struct audit_krule *r)
1374 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1375 struct audit_entry *nentry;
1378 if (!security_audit_rule_known(r))
1381 nentry = audit_dupe_rule(r);
1382 if (entry->rule.exe)
1383 audit_remove_mark(entry->rule.exe);
1384 if (IS_ERR(nentry)) {
1385 /* save the first error encountered for the
1387 err = PTR_ERR(nentry);
1388 audit_panic("error updating LSM filters");
1390 list_del(&r->rlist);
1391 list_del_rcu(&entry->list);
1394 if (r->watch || r->tree)
1395 list_replace_init(&r->rlist, &nentry->rule.rlist);
1396 list_replace_rcu(&entry->list, &nentry->list);
1397 list_replace(&r->list, &nentry->rule.list);
1399 call_rcu(&entry->rcu, audit_free_rule_rcu);
1404 /* This function will re-initialize the lsm_rule field of all applicable rules.
1405 * It will traverse the filter lists serarching for rules that contain LSM
1406 * specific filter fields. When such a rule is found, it is copied, the
1407 * LSM field is re-initialized, and the old rule is replaced with the
1409 int audit_update_lsm_rules(void)
1411 struct audit_krule *r, *n;
1414 /* audit_filter_mutex synchronizes the writers */
1415 mutex_lock(&audit_filter_mutex);
1417 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1418 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1419 int res = update_lsm_rule(r);
1424 mutex_unlock(&audit_filter_mutex);