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:
384 case AUDIT_SESSIONID:
385 /* bit ops are only useful on syscall args */
386 if (f->op == Audit_bitmask || f->op == Audit_bittest)
393 case AUDIT_SUBJ_USER:
394 case AUDIT_SUBJ_ROLE:
395 case AUDIT_SUBJ_TYPE:
401 case AUDIT_OBJ_LEV_LOW:
402 case AUDIT_OBJ_LEV_HIGH:
405 case AUDIT_FILTERKEY:
407 case AUDIT_LOGINUID_SET:
408 if ((f->val != 0) && (f->val != 1))
413 if (f->op != Audit_not_equal && f->op != Audit_equal)
421 if (f->val & ~S_IFMT)
424 case AUDIT_FIELD_COMPARE:
425 if (f->val > AUDIT_MAX_FIELD_COMPARE)
429 if (f->op != Audit_not_equal && f->op != Audit_equal)
436 /* Translate struct audit_rule_data to kernel's rule representation. */
437 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
441 struct audit_entry *entry;
443 size_t remain = datasz - sizeof(struct audit_rule_data);
446 struct audit_fsnotify_mark *audit_mark;
448 entry = audit_to_entry_common(data);
453 for (i = 0; i < data->field_count; i++) {
454 struct audit_field *f = &entry->rule.fields[i];
458 f->op = audit_to_op(data->fieldflags[i]);
459 if (f->op == Audit_bad)
462 f->type = data->fields[i];
463 f->val = data->values[i];
465 /* Support legacy tests for a valid loginuid */
466 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
467 f->type = AUDIT_LOGINUID_SET;
469 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
472 err = audit_field_valid(entry, f);
484 f->uid = make_kuid(current_user_ns(), f->val);
485 if (!uid_valid(f->uid))
493 f->gid = make_kgid(current_user_ns(), f->val);
494 if (!gid_valid(f->gid))
498 entry->rule.arch_f = f;
500 case AUDIT_SUBJ_USER:
501 case AUDIT_SUBJ_ROLE:
502 case AUDIT_SUBJ_TYPE:
508 case AUDIT_OBJ_LEV_LOW:
509 case AUDIT_OBJ_LEV_HIGH:
510 str = audit_unpack_string(&bufp, &remain, f->val);
513 entry->rule.buflen += f->val;
515 err = security_audit_rule_init(f->type, f->op, str,
516 (void **)&f->lsm_rule);
517 /* Keep currently invalid fields around in case they
518 * become valid after a policy reload. */
519 if (err == -EINVAL) {
520 pr_warn("audit rule for LSM \'%s\' is invalid\n",
531 str = audit_unpack_string(&bufp, &remain, f->val);
534 entry->rule.buflen += f->val;
536 err = audit_to_watch(&entry->rule, str, f->val, f->op);
543 str = audit_unpack_string(&bufp, &remain, f->val);
546 entry->rule.buflen += f->val;
548 err = audit_make_tree(&entry->rule, str, f->op);
554 err = audit_to_inode(&entry->rule, f);
558 case AUDIT_FILTERKEY:
559 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
561 str = audit_unpack_string(&bufp, &remain, f->val);
564 entry->rule.buflen += f->val;
565 entry->rule.filterkey = str;
568 if (entry->rule.exe || f->val > PATH_MAX)
570 str = audit_unpack_string(&bufp, &remain, f->val);
575 entry->rule.buflen += f->val;
577 audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
578 if (IS_ERR(audit_mark)) {
580 err = PTR_ERR(audit_mark);
583 entry->rule.exe = audit_mark;
588 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
589 entry->rule.inode_f = NULL;
595 if (entry->rule.tree)
596 audit_put_tree(entry->rule.tree); /* that's the temporary one */
598 audit_remove_mark(entry->rule.exe); /* that's the template one */
599 audit_free_rule(entry);
603 /* Pack a filter field's string representation into data block. */
604 static inline size_t audit_pack_string(void **bufp, const char *str)
606 size_t len = strlen(str);
608 memcpy(*bufp, str, len);
614 /* Translate kernel rule representation to struct audit_rule_data. */
615 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
617 struct audit_rule_data *data;
621 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
624 memset(data, 0, sizeof(*data));
626 data->flags = krule->flags | krule->listnr;
627 data->action = krule->action;
628 data->field_count = krule->field_count;
630 for (i = 0; i < data->field_count; i++) {
631 struct audit_field *f = &krule->fields[i];
633 data->fields[i] = f->type;
634 data->fieldflags[i] = audit_ops[f->op];
636 case AUDIT_SUBJ_USER:
637 case AUDIT_SUBJ_ROLE:
638 case AUDIT_SUBJ_TYPE:
644 case AUDIT_OBJ_LEV_LOW:
645 case AUDIT_OBJ_LEV_HIGH:
646 data->buflen += data->values[i] =
647 audit_pack_string(&bufp, f->lsm_str);
650 data->buflen += data->values[i] =
651 audit_pack_string(&bufp,
652 audit_watch_path(krule->watch));
655 data->buflen += data->values[i] =
656 audit_pack_string(&bufp,
657 audit_tree_path(krule->tree));
659 case AUDIT_FILTERKEY:
660 data->buflen += data->values[i] =
661 audit_pack_string(&bufp, krule->filterkey);
664 data->buflen += data->values[i] =
665 audit_pack_string(&bufp, audit_mark_path(krule->exe));
667 case AUDIT_LOGINUID_SET:
668 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
669 data->fields[i] = AUDIT_LOGINUID;
670 data->values[i] = AUDIT_UID_UNSET;
673 /* fall through - if set */
675 data->values[i] = f->val;
678 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
683 /* Compare two rules in kernel format. Considered success if rules
685 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
689 if (a->flags != b->flags ||
690 a->pflags != b->pflags ||
691 a->listnr != b->listnr ||
692 a->action != b->action ||
693 a->field_count != b->field_count)
696 for (i = 0; i < a->field_count; i++) {
697 if (a->fields[i].type != b->fields[i].type ||
698 a->fields[i].op != b->fields[i].op)
701 switch(a->fields[i].type) {
702 case AUDIT_SUBJ_USER:
703 case AUDIT_SUBJ_ROLE:
704 case AUDIT_SUBJ_TYPE:
710 case AUDIT_OBJ_LEV_LOW:
711 case AUDIT_OBJ_LEV_HIGH:
712 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
716 if (strcmp(audit_watch_path(a->watch),
717 audit_watch_path(b->watch)))
721 if (strcmp(audit_tree_path(a->tree),
722 audit_tree_path(b->tree)))
725 case AUDIT_FILTERKEY:
726 /* both filterkeys exist based on above type compare */
727 if (strcmp(a->filterkey, b->filterkey))
731 /* both paths exist based on above type compare */
732 if (strcmp(audit_mark_path(a->exe),
733 audit_mark_path(b->exe)))
742 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
750 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
754 if (a->fields[i].val != b->fields[i].val)
759 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
760 if (a->mask[i] != b->mask[i])
766 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
768 static inline int audit_dupe_lsm_field(struct audit_field *df,
769 struct audit_field *sf)
774 /* our own copy of lsm_str */
775 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
776 if (unlikely(!lsm_str))
778 df->lsm_str = lsm_str;
780 /* our own (refreshed) copy of lsm_rule */
781 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
782 (void **)&df->lsm_rule);
783 /* Keep currently invalid fields around in case they
784 * become valid after a policy reload. */
785 if (ret == -EINVAL) {
786 pr_warn("audit rule for LSM \'%s\' is invalid\n",
794 /* Duplicate an audit rule. This will be a deep copy with the exception
795 * of the watch - that pointer is carried over. The LSM specific fields
796 * will be updated in the copy. The point is to be able to replace the old
797 * rule with the new rule in the filterlist, then free the old rule.
798 * The rlist element is undefined; list manipulations are handled apart from
799 * the initial copy. */
800 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
802 u32 fcount = old->field_count;
803 struct audit_entry *entry;
804 struct audit_krule *new;
808 entry = audit_init_entry(fcount);
809 if (unlikely(!entry))
810 return ERR_PTR(-ENOMEM);
813 new->flags = old->flags;
814 new->pflags = old->pflags;
815 new->listnr = old->listnr;
816 new->action = old->action;
817 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
818 new->mask[i] = old->mask[i];
819 new->prio = old->prio;
820 new->buflen = old->buflen;
821 new->inode_f = old->inode_f;
822 new->field_count = old->field_count;
825 * note that we are OK with not refcounting here; audit_match_tree()
826 * never dereferences tree and we can't get false positives there
827 * since we'd have to have rule gone from the list *and* removed
828 * before the chunks found by lookup had been allocated, i.e. before
829 * the beginning of list scan.
831 new->tree = old->tree;
832 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
834 /* deep copy this information, updating the lsm_rule fields, because
835 * the originals will all be freed when the old rule is freed. */
836 for (i = 0; i < fcount; i++) {
837 switch (new->fields[i].type) {
838 case AUDIT_SUBJ_USER:
839 case AUDIT_SUBJ_ROLE:
840 case AUDIT_SUBJ_TYPE:
846 case AUDIT_OBJ_LEV_LOW:
847 case AUDIT_OBJ_LEV_HIGH:
848 err = audit_dupe_lsm_field(&new->fields[i],
851 case AUDIT_FILTERKEY:
852 fk = kstrdup(old->filterkey, GFP_KERNEL);
859 err = audit_dupe_exe(new, old);
864 audit_remove_mark(new->exe);
865 audit_free_rule(entry);
871 audit_get_watch(old->watch);
872 new->watch = old->watch;
878 /* Find an existing audit rule.
879 * Caller must hold audit_filter_mutex to prevent stale rule data. */
880 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
881 struct list_head **p)
883 struct audit_entry *e, *found = NULL;
884 struct list_head *list;
887 if (entry->rule.inode_f) {
888 h = audit_hash_ino(entry->rule.inode_f->val);
889 *p = list = &audit_inode_hash[h];
890 } else if (entry->rule.watch) {
891 /* we don't know the inode number, so must walk entire hash */
892 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
893 list = &audit_inode_hash[h];
894 list_for_each_entry(e, list, list)
895 if (!audit_compare_rule(&entry->rule, &e->rule)) {
902 *p = list = &audit_filter_list[entry->rule.listnr];
905 list_for_each_entry(e, list, list)
906 if (!audit_compare_rule(&entry->rule, &e->rule)) {
915 static u64 prio_low = ~0ULL/2;
916 static u64 prio_high = ~0ULL/2 - 1;
918 /* Add rule to given filterlist if not a duplicate. */
919 static inline int audit_add_rule(struct audit_entry *entry)
921 struct audit_entry *e;
922 struct audit_watch *watch = entry->rule.watch;
923 struct audit_tree *tree = entry->rule.tree;
924 struct list_head *list;
926 #ifdef CONFIG_AUDITSYSCALL
929 /* If any of these, don't count towards total */
930 switch(entry->rule.listnr) {
931 case AUDIT_FILTER_USER:
932 case AUDIT_FILTER_EXCLUDE:
933 case AUDIT_FILTER_FS:
938 mutex_lock(&audit_filter_mutex);
939 e = audit_find_rule(entry, &list);
941 mutex_unlock(&audit_filter_mutex);
943 /* normally audit_add_tree_rule() will free it on failure */
945 audit_put_tree(tree);
950 /* audit_filter_mutex is dropped and re-taken during this call */
951 err = audit_add_watch(&entry->rule, &list);
953 mutex_unlock(&audit_filter_mutex);
955 * normally audit_add_tree_rule() will free it
959 audit_put_tree(tree);
964 err = audit_add_tree_rule(&entry->rule);
966 mutex_unlock(&audit_filter_mutex);
971 entry->rule.prio = ~0ULL;
972 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
973 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
974 entry->rule.prio = ++prio_high;
976 entry->rule.prio = --prio_low;
979 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
980 list_add(&entry->rule.list,
981 &audit_rules_list[entry->rule.listnr]);
982 list_add_rcu(&entry->list, list);
983 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
985 list_add_tail(&entry->rule.list,
986 &audit_rules_list[entry->rule.listnr]);
987 list_add_tail_rcu(&entry->list, list);
989 #ifdef CONFIG_AUDITSYSCALL
993 if (!audit_match_signal(entry))
996 mutex_unlock(&audit_filter_mutex);
1001 /* Remove an existing rule from filterlist. */
1002 int audit_del_rule(struct audit_entry *entry)
1004 struct audit_entry *e;
1005 struct audit_tree *tree = entry->rule.tree;
1006 struct list_head *list;
1008 #ifdef CONFIG_AUDITSYSCALL
1011 /* If any of these, don't count towards total */
1012 switch(entry->rule.listnr) {
1013 case AUDIT_FILTER_USER:
1014 case AUDIT_FILTER_EXCLUDE:
1015 case AUDIT_FILTER_FS:
1020 mutex_lock(&audit_filter_mutex);
1021 e = audit_find_rule(entry, &list);
1028 audit_remove_watch_rule(&e->rule);
1031 audit_remove_tree_rule(&e->rule);
1034 audit_remove_mark_rule(&e->rule);
1036 #ifdef CONFIG_AUDITSYSCALL
1040 if (!audit_match_signal(entry))
1044 list_del_rcu(&e->list);
1045 list_del(&e->rule.list);
1046 call_rcu(&e->rcu, audit_free_rule_rcu);
1049 mutex_unlock(&audit_filter_mutex);
1052 audit_put_tree(tree); /* that's the temporary one */
1057 /* List rules using struct audit_rule_data. */
1058 static void audit_list_rules(int seq, struct sk_buff_head *q)
1060 struct sk_buff *skb;
1061 struct audit_krule *r;
1064 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1065 * iterator to sync with list writers. */
1066 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1067 list_for_each_entry(r, &audit_rules_list[i], list) {
1068 struct audit_rule_data *data;
1070 data = audit_krule_to_data(r);
1071 if (unlikely(!data))
1073 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1075 sizeof(*data) + data->buflen);
1077 skb_queue_tail(q, skb);
1081 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1083 skb_queue_tail(q, skb);
1086 /* Log rule additions and removals */
1087 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1089 struct audit_buffer *ab;
1094 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1097 audit_log_session_info(ab);
1098 audit_log_task_context(ab);
1099 audit_log_format(ab, " op=%s", action);
1100 audit_log_key(ab, rule->filterkey);
1101 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1106 * audit_rule_change - apply all rules to the specified message type
1107 * @type: audit message type
1108 * @seq: netlink audit message sequence (serial) number
1109 * @data: payload data
1110 * @datasz: size of payload data
1112 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1115 struct audit_entry *entry;
1117 entry = audit_data_to_entry(data, datasz);
1119 return PTR_ERR(entry);
1122 case AUDIT_ADD_RULE:
1123 err = audit_add_rule(entry);
1124 audit_log_rule_change("add_rule", &entry->rule, !err);
1126 case AUDIT_DEL_RULE:
1127 err = audit_del_rule(entry);
1128 audit_log_rule_change("remove_rule", &entry->rule, !err);
1135 if (err || type == AUDIT_DEL_RULE) {
1136 if (entry->rule.exe)
1137 audit_remove_mark(entry->rule.exe);
1138 audit_free_rule(entry);
1145 * audit_list_rules_send - list the audit rules
1146 * @request_skb: skb of request we are replying to (used to target the reply)
1147 * @seq: netlink audit message sequence (serial) number
1149 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1151 u32 portid = NETLINK_CB(request_skb).portid;
1152 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1153 struct task_struct *tsk;
1154 struct audit_netlink_list *dest;
1157 /* We can't just spew out the rules here because we might fill
1158 * the available socket buffer space and deadlock waiting for
1159 * auditctl to read from it... which isn't ever going to
1160 * happen if we're actually running in the context of auditctl
1161 * trying to _send_ the stuff */
1163 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1166 dest->net = get_net(net);
1167 dest->portid = portid;
1168 skb_queue_head_init(&dest->q);
1170 mutex_lock(&audit_filter_mutex);
1171 audit_list_rules(seq, &dest->q);
1172 mutex_unlock(&audit_filter_mutex);
1174 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1176 skb_queue_purge(&dest->q);
1184 int audit_comparator(u32 left, u32 op, u32 right)
1188 return (left == right);
1189 case Audit_not_equal:
1190 return (left != right);
1192 return (left < right);
1194 return (left <= right);
1196 return (left > right);
1198 return (left >= right);
1200 return (left & right);
1202 return ((left & right) == right);
1209 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1213 return uid_eq(left, right);
1214 case Audit_not_equal:
1215 return !uid_eq(left, right);
1217 return uid_lt(left, right);
1219 return uid_lte(left, right);
1221 return uid_gt(left, right);
1223 return uid_gte(left, right);
1232 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1236 return gid_eq(left, right);
1237 case Audit_not_equal:
1238 return !gid_eq(left, right);
1240 return gid_lt(left, right);
1242 return gid_lte(left, right);
1244 return gid_gt(left, right);
1246 return gid_gte(left, right);
1256 * parent_len - find the length of the parent portion of a pathname
1257 * @path: pathname of which to determine length
1259 int parent_len(const char *path)
1264 plen = strlen(path);
1269 /* disregard trailing slashes */
1270 p = path + plen - 1;
1271 while ((*p == '/') && (p > path))
1274 /* walk backward until we find the next slash or hit beginning */
1275 while ((*p != '/') && (p > path))
1278 /* did we find a slash? Then increment to include it in path */
1286 * audit_compare_dname_path - compare given dentry name with last component in
1287 * given path. Return of 0 indicates a match.
1288 * @dname: dentry name that we're comparing
1289 * @path: full pathname that we're comparing
1290 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1291 * here indicates that we must compute this value.
1293 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1298 dlen = strlen(dname);
1299 pathlen = strlen(path);
1303 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1304 if (pathlen - parentlen != dlen)
1307 p = path + parentlen;
1309 return strncmp(p, dname, dlen);
1312 int audit_filter(int msgtype, unsigned int listtype)
1314 struct audit_entry *e;
1315 int ret = 1; /* Audit by default */
1318 if (list_empty(&audit_filter_list[listtype]))
1319 goto unlock_and_return;
1320 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1323 for (i = 0; i < e->rule.field_count; i++) {
1324 struct audit_field *f = &e->rule.fields[i];
1330 pid = task_pid_nr(current);
1331 result = audit_comparator(pid, f->op, f->val);
1334 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1337 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1339 case AUDIT_LOGINUID:
1340 result = audit_uid_comparator(audit_get_loginuid(current),
1343 case AUDIT_LOGINUID_SET:
1344 result = audit_comparator(audit_loginuid_set(current),
1348 result = audit_comparator(msgtype, f->op, f->val);
1350 case AUDIT_SUBJ_USER:
1351 case AUDIT_SUBJ_ROLE:
1352 case AUDIT_SUBJ_TYPE:
1353 case AUDIT_SUBJ_SEN:
1354 case AUDIT_SUBJ_CLR:
1356 security_task_getsecid(current, &sid);
1357 result = security_audit_rule_match(sid,
1358 f->type, f->op, f->lsm_rule);
1362 result = audit_exe_compare(current, e->rule.exe);
1363 if (f->op == Audit_not_equal)
1367 goto unlock_and_return;
1369 if (result < 0) /* error */
1370 goto unlock_and_return;
1375 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1385 static int update_lsm_rule(struct audit_krule *r)
1387 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1388 struct audit_entry *nentry;
1391 if (!security_audit_rule_known(r))
1394 nentry = audit_dupe_rule(r);
1395 if (entry->rule.exe)
1396 audit_remove_mark(entry->rule.exe);
1397 if (IS_ERR(nentry)) {
1398 /* save the first error encountered for the
1400 err = PTR_ERR(nentry);
1401 audit_panic("error updating LSM filters");
1403 list_del(&r->rlist);
1404 list_del_rcu(&entry->list);
1407 if (r->watch || r->tree)
1408 list_replace_init(&r->rlist, &nentry->rule.rlist);
1409 list_replace_rcu(&entry->list, &nentry->list);
1410 list_replace(&r->list, &nentry->rule.list);
1412 call_rcu(&entry->rcu, audit_free_rule_rcu);
1417 /* This function will re-initialize the lsm_rule field of all applicable rules.
1418 * It will traverse the filter lists serarching for rules that contain LSM
1419 * specific filter fields. When such a rule is found, it is copied, the
1420 * LSM field is re-initialized, and the old rule is replaced with the
1422 int audit_update_lsm_rules(void)
1424 struct audit_krule *r, *n;
1427 /* audit_filter_mutex synchronizes the writers */
1428 mutex_lock(&audit_filter_mutex);
1430 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1431 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1432 int res = update_lsm_rule(r);
1437 mutex_unlock(&audit_filter_mutex);