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 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/slab.h>
31 #include <linux/security.h>
38 * Synchronizes writes and blocking reads of audit's filterlist
39 * data. Rcu is used to traverse the filterlist and access
40 * contents of structs audit_entry, audit_watch and opaque
41 * LSM rules during filtering. If modified, these structures
42 * must be copied and replace their counterparts in the filterlist.
43 * An audit_parent struct is not accessed during filtering, so may
44 * be written directly provided audit_filter_mutex is held.
47 /* Audit filter lists, defined in <linux/audit.h> */
48 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
49 LIST_HEAD_INIT(audit_filter_list[0]),
50 LIST_HEAD_INIT(audit_filter_list[1]),
51 LIST_HEAD_INIT(audit_filter_list[2]),
52 LIST_HEAD_INIT(audit_filter_list[3]),
53 LIST_HEAD_INIT(audit_filter_list[4]),
54 LIST_HEAD_INIT(audit_filter_list[5]),
55 #if AUDIT_NR_FILTERS != 6
56 #error Fix audit_filter_list initialiser
59 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
60 LIST_HEAD_INIT(audit_rules_list[0]),
61 LIST_HEAD_INIT(audit_rules_list[1]),
62 LIST_HEAD_INIT(audit_rules_list[2]),
63 LIST_HEAD_INIT(audit_rules_list[3]),
64 LIST_HEAD_INIT(audit_rules_list[4]),
65 LIST_HEAD_INIT(audit_rules_list[5]),
68 DEFINE_MUTEX(audit_filter_mutex);
70 static inline void audit_free_rule(struct audit_entry *e)
73 struct audit_krule *erule = &e->rule;
75 /* some rules don't have associated watches */
77 audit_put_watch(erule->watch);
79 for (i = 0; i < erule->field_count; i++) {
80 struct audit_field *f = &erule->fields[i];
82 security_audit_rule_free(f->lsm_rule);
85 kfree(erule->filterkey);
89 void audit_free_rule_rcu(struct rcu_head *head)
91 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
95 /* Initialize an audit filterlist entry. */
96 static inline struct audit_entry *audit_init_entry(u32 field_count)
98 struct audit_entry *entry;
99 struct audit_field *fields;
101 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
102 if (unlikely(!entry))
105 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
106 if (unlikely(!fields)) {
110 entry->rule.fields = fields;
115 /* Unpack a filter field's string representation from user-space
117 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
121 if (!*bufp || (len == 0) || (len > *remain))
122 return ERR_PTR(-EINVAL);
124 /* Of the currently implemented string fields, PATH_MAX
125 * defines the longest valid length.
128 return ERR_PTR(-ENAMETOOLONG);
130 str = kmalloc(len + 1, GFP_KERNEL);
132 return ERR_PTR(-ENOMEM);
134 memcpy(str, *bufp, len);
142 /* Translate an inode field to kernel respresentation. */
143 static inline int audit_to_inode(struct audit_krule *krule,
144 struct audit_field *f)
146 if (krule->listnr != AUDIT_FILTER_EXIT ||
147 krule->watch || krule->inode_f || krule->tree ||
148 (f->op != Audit_equal && f->op != Audit_not_equal))
155 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
157 int __init audit_register_class(int class, unsigned *list)
159 __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
162 while (*list != ~0U) {
163 unsigned n = *list++;
164 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
168 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
170 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
178 int audit_match_class(int class, unsigned syscall)
180 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
182 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
184 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
187 #ifdef CONFIG_AUDITSYSCALL
188 static inline int audit_match_class_bits(int class, u32 *mask)
192 if (classes[class]) {
193 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
194 if (mask[i] & classes[class][i])
200 static int audit_match_signal(struct audit_entry *entry)
202 struct audit_field *arch = entry->rule.arch_f;
205 /* When arch is unspecified, we must check both masks on biarch
206 * as syscall number alone is ambiguous. */
207 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
209 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
213 switch(audit_classify_arch(arch->val)) {
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
217 case 1: /* 32bit on biarch */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
226 /* Common user-space to kernel rule translation. */
227 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
230 struct audit_entry *entry;
234 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
238 #ifdef CONFIG_AUDITSYSCALL
239 case AUDIT_FILTER_ENTRY:
240 if (rule->action == AUDIT_ALWAYS)
242 case AUDIT_FILTER_EXIT:
243 case AUDIT_FILTER_TASK:
245 case AUDIT_FILTER_USER:
246 case AUDIT_FILTER_TYPE:
249 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
250 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
253 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
255 if (rule->field_count > AUDIT_MAX_FIELDS)
259 entry = audit_init_entry(rule->field_count);
263 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
264 entry->rule.listnr = listnr;
265 entry->rule.action = rule->action;
266 entry->rule.field_count = rule->field_count;
268 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
269 entry->rule.mask[i] = rule->mask[i];
271 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
272 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
273 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
276 if (!(*p & AUDIT_BIT(bit)))
278 *p &= ~AUDIT_BIT(bit);
282 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
283 entry->rule.mask[j] |= class[j];
293 static u32 audit_ops[] =
295 [Audit_equal] = AUDIT_EQUAL,
296 [Audit_not_equal] = AUDIT_NOT_EQUAL,
297 [Audit_bitmask] = AUDIT_BIT_MASK,
298 [Audit_bittest] = AUDIT_BIT_TEST,
299 [Audit_lt] = AUDIT_LESS_THAN,
300 [Audit_gt] = AUDIT_GREATER_THAN,
301 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
302 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
305 static u32 audit_to_op(u32 op)
308 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
314 /* Translate struct audit_rule to kernel's rule respresentation.
315 * Exists for backward compatibility with userspace. */
316 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
318 struct audit_entry *entry;
322 entry = audit_to_entry_common(rule);
326 for (i = 0; i < rule->field_count; i++) {
327 struct audit_field *f = &entry->rule.fields[i];
330 n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
332 /* Support for legacy operators where
333 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
334 if (n & AUDIT_NEGATE)
335 f->op = Audit_not_equal;
339 f->op = audit_to_op(n);
341 entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1;
343 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
344 f->val = rule->values[i];
347 if (f->op == Audit_bad)
370 /* bit ops are only useful on syscall args */
371 if (f->op == Audit_bitmask || f->op == Audit_bittest)
379 /* arch is only allowed to be = or != */
381 if (f->op != Audit_not_equal && f->op != Audit_equal)
383 entry->rule.arch_f = f;
390 if (f->val & ~S_IFMT)
394 err = audit_to_inode(&entry->rule, f);
401 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
402 entry->rule.inode_f = NULL;
408 audit_free_rule(entry);
412 /* Translate struct audit_rule_data to kernel's rule respresentation. */
413 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
417 struct audit_entry *entry;
419 size_t remain = datasz - sizeof(struct audit_rule_data);
423 entry = audit_to_entry_common((struct audit_rule *)data);
428 entry->rule.vers_ops = 2;
429 for (i = 0; i < data->field_count; i++) {
430 struct audit_field *f = &entry->rule.fields[i];
434 f->op = audit_to_op(data->fieldflags[i]);
435 if (f->op == Audit_bad)
438 f->type = data->fields[i];
439 f->val = data->values[i];
466 entry->rule.arch_f = f;
468 case AUDIT_SUBJ_USER:
469 case AUDIT_SUBJ_ROLE:
470 case AUDIT_SUBJ_TYPE:
476 case AUDIT_OBJ_LEV_LOW:
477 case AUDIT_OBJ_LEV_HIGH:
478 str = audit_unpack_string(&bufp, &remain, f->val);
481 entry->rule.buflen += f->val;
483 err = security_audit_rule_init(f->type, f->op, str,
484 (void **)&f->lsm_rule);
485 /* Keep currently invalid fields around in case they
486 * become valid after a policy reload. */
487 if (err == -EINVAL) {
488 printk(KERN_WARNING "audit rule for LSM "
489 "\'%s\' is invalid\n", str);
499 str = audit_unpack_string(&bufp, &remain, f->val);
502 entry->rule.buflen += f->val;
504 err = audit_to_watch(&entry->rule, str, f->val, f->op);
511 str = audit_unpack_string(&bufp, &remain, f->val);
514 entry->rule.buflen += f->val;
516 err = audit_make_tree(&entry->rule, str, f->op);
522 err = audit_to_inode(&entry->rule, f);
526 case AUDIT_FILTERKEY:
528 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
530 str = audit_unpack_string(&bufp, &remain, f->val);
533 entry->rule.buflen += f->val;
534 entry->rule.filterkey = str;
541 if (f->val & ~S_IFMT)
549 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
550 entry->rule.inode_f = NULL;
556 audit_free_rule(entry);
560 /* Pack a filter field's string representation into data block. */
561 static inline size_t audit_pack_string(void **bufp, const char *str)
563 size_t len = strlen(str);
565 memcpy(*bufp, str, len);
571 /* Translate kernel rule respresentation to struct audit_rule.
572 * Exists for backward compatibility with userspace. */
573 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
575 struct audit_rule *rule;
578 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
582 rule->flags = krule->flags | krule->listnr;
583 rule->action = krule->action;
584 rule->field_count = krule->field_count;
585 for (i = 0; i < rule->field_count; i++) {
586 rule->values[i] = krule->fields[i].val;
587 rule->fields[i] = krule->fields[i].type;
589 if (krule->vers_ops == 1) {
590 if (krule->fields[i].op == Audit_not_equal)
591 rule->fields[i] |= AUDIT_NEGATE;
593 rule->fields[i] |= audit_ops[krule->fields[i].op];
596 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
601 /* Translate kernel rule respresentation 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->values[i] = f->val;
654 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
659 /* Compare two rules in kernel format. Considered success if rules
661 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
665 if (a->flags != b->flags ||
666 a->listnr != b->listnr ||
667 a->action != b->action ||
668 a->field_count != b->field_count)
671 for (i = 0; i < a->field_count; i++) {
672 if (a->fields[i].type != b->fields[i].type ||
673 a->fields[i].op != b->fields[i].op)
676 switch(a->fields[i].type) {
677 case AUDIT_SUBJ_USER:
678 case AUDIT_SUBJ_ROLE:
679 case AUDIT_SUBJ_TYPE:
685 case AUDIT_OBJ_LEV_LOW:
686 case AUDIT_OBJ_LEV_HIGH:
687 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
691 if (strcmp(audit_watch_path(a->watch),
692 audit_watch_path(b->watch)))
696 if (strcmp(audit_tree_path(a->tree),
697 audit_tree_path(b->tree)))
700 case AUDIT_FILTERKEY:
701 /* both filterkeys exist based on above type compare */
702 if (strcmp(a->filterkey, b->filterkey))
706 if (a->fields[i].val != b->fields[i].val)
711 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
712 if (a->mask[i] != b->mask[i])
718 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
720 static inline int audit_dupe_lsm_field(struct audit_field *df,
721 struct audit_field *sf)
726 /* our own copy of lsm_str */
727 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
728 if (unlikely(!lsm_str))
730 df->lsm_str = lsm_str;
732 /* our own (refreshed) copy of lsm_rule */
733 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
734 (void **)&df->lsm_rule);
735 /* Keep currently invalid fields around in case they
736 * become valid after a policy reload. */
737 if (ret == -EINVAL) {
738 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
739 "invalid\n", df->lsm_str);
746 /* Duplicate an audit rule. This will be a deep copy with the exception
747 * of the watch - that pointer is carried over. The LSM specific fields
748 * will be updated in the copy. The point is to be able to replace the old
749 * rule with the new rule in the filterlist, then free the old rule.
750 * The rlist element is undefined; list manipulations are handled apart from
751 * the initial copy. */
752 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
754 u32 fcount = old->field_count;
755 struct audit_entry *entry;
756 struct audit_krule *new;
760 entry = audit_init_entry(fcount);
761 if (unlikely(!entry))
762 return ERR_PTR(-ENOMEM);
765 new->vers_ops = old->vers_ops;
766 new->flags = old->flags;
767 new->listnr = old->listnr;
768 new->action = old->action;
769 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
770 new->mask[i] = old->mask[i];
771 new->prio = old->prio;
772 new->buflen = old->buflen;
773 new->inode_f = old->inode_f;
774 new->field_count = old->field_count;
777 * note that we are OK with not refcounting here; audit_match_tree()
778 * never dereferences tree and we can't get false positives there
779 * since we'd have to have rule gone from the list *and* removed
780 * before the chunks found by lookup had been allocated, i.e. before
781 * the beginning of list scan.
783 new->tree = old->tree;
784 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
786 /* deep copy this information, updating the lsm_rule fields, because
787 * the originals will all be freed when the old rule is freed. */
788 for (i = 0; i < fcount; i++) {
789 switch (new->fields[i].type) {
790 case AUDIT_SUBJ_USER:
791 case AUDIT_SUBJ_ROLE:
792 case AUDIT_SUBJ_TYPE:
798 case AUDIT_OBJ_LEV_LOW:
799 case AUDIT_OBJ_LEV_HIGH:
800 err = audit_dupe_lsm_field(&new->fields[i],
803 case AUDIT_FILTERKEY:
804 fk = kstrdup(old->filterkey, GFP_KERNEL);
811 audit_free_rule(entry);
817 audit_get_watch(old->watch);
818 new->watch = old->watch;
824 /* Find an existing audit rule.
825 * Caller must hold audit_filter_mutex to prevent stale rule data. */
826 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
827 struct list_head **p)
829 struct audit_entry *e, *found = NULL;
830 struct list_head *list;
833 if (entry->rule.inode_f) {
834 h = audit_hash_ino(entry->rule.inode_f->val);
835 *p = list = &audit_inode_hash[h];
836 } else if (entry->rule.watch) {
837 /* we don't know the inode number, so must walk entire hash */
838 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
839 list = &audit_inode_hash[h];
840 list_for_each_entry(e, list, list)
841 if (!audit_compare_rule(&entry->rule, &e->rule)) {
848 *p = list = &audit_filter_list[entry->rule.listnr];
851 list_for_each_entry(e, list, list)
852 if (!audit_compare_rule(&entry->rule, &e->rule)) {
861 static u64 prio_low = ~0ULL/2;
862 static u64 prio_high = ~0ULL/2 - 1;
864 /* Add rule to given filterlist if not a duplicate. */
865 static inline int audit_add_rule(struct audit_entry *entry)
867 struct audit_entry *e;
868 struct audit_watch *watch = entry->rule.watch;
869 struct audit_tree *tree = entry->rule.tree;
870 struct list_head *list;
872 #ifdef CONFIG_AUDITSYSCALL
875 /* If either of these, don't count towards total */
876 if (entry->rule.listnr == AUDIT_FILTER_USER ||
877 entry->rule.listnr == AUDIT_FILTER_TYPE)
881 mutex_lock(&audit_filter_mutex);
882 e = audit_find_rule(entry, &list);
884 mutex_unlock(&audit_filter_mutex);
886 /* normally audit_add_tree_rule() will free it on failure */
888 audit_put_tree(tree);
893 /* audit_filter_mutex is dropped and re-taken during this call */
894 err = audit_add_watch(&entry->rule, &list);
896 mutex_unlock(&audit_filter_mutex);
901 err = audit_add_tree_rule(&entry->rule);
903 mutex_unlock(&audit_filter_mutex);
908 entry->rule.prio = ~0ULL;
909 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
910 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
911 entry->rule.prio = ++prio_high;
913 entry->rule.prio = --prio_low;
916 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
917 list_add(&entry->rule.list,
918 &audit_rules_list[entry->rule.listnr]);
919 list_add_rcu(&entry->list, list);
920 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
922 list_add_tail(&entry->rule.list,
923 &audit_rules_list[entry->rule.listnr]);
924 list_add_tail_rcu(&entry->list, list);
926 #ifdef CONFIG_AUDITSYSCALL
930 if (!audit_match_signal(entry))
933 mutex_unlock(&audit_filter_mutex);
939 audit_put_watch(watch); /* tmp watch, matches initial get */
943 /* Remove an existing rule from filterlist. */
944 static inline int audit_del_rule(struct audit_entry *entry)
946 struct audit_entry *e;
947 struct audit_watch *watch = entry->rule.watch;
948 struct audit_tree *tree = entry->rule.tree;
949 struct list_head *list;
951 #ifdef CONFIG_AUDITSYSCALL
954 /* If either of these, don't count towards total */
955 if (entry->rule.listnr == AUDIT_FILTER_USER ||
956 entry->rule.listnr == AUDIT_FILTER_TYPE)
960 mutex_lock(&audit_filter_mutex);
961 e = audit_find_rule(entry, &list);
963 mutex_unlock(&audit_filter_mutex);
969 audit_remove_watch_rule(&e->rule);
972 audit_remove_tree_rule(&e->rule);
974 list_del_rcu(&e->list);
975 list_del(&e->rule.list);
976 call_rcu(&e->rcu, audit_free_rule_rcu);
978 #ifdef CONFIG_AUDITSYSCALL
982 if (!audit_match_signal(entry))
985 mutex_unlock(&audit_filter_mutex);
989 audit_put_watch(watch); /* match initial get */
991 audit_put_tree(tree); /* that's the temporary one */
996 /* List rules using struct audit_rule. Exists for backward
997 * compatibility with userspace. */
998 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1000 struct sk_buff *skb;
1001 struct audit_krule *r;
1004 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1005 * iterator to sync with list writers. */
1006 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1007 list_for_each_entry(r, &audit_rules_list[i], list) {
1008 struct audit_rule *rule;
1010 rule = audit_krule_to_rule(r);
1011 if (unlikely(!rule))
1013 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1014 rule, sizeof(*rule));
1016 skb_queue_tail(q, skb);
1020 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1022 skb_queue_tail(q, skb);
1025 /* List rules using struct audit_rule_data. */
1026 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1028 struct sk_buff *skb;
1029 struct audit_krule *r;
1032 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1033 * iterator to sync with list writers. */
1034 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1035 list_for_each_entry(r, &audit_rules_list[i], list) {
1036 struct audit_rule_data *data;
1038 data = audit_krule_to_data(r);
1039 if (unlikely(!data))
1041 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1042 data, sizeof(*data) + data->buflen);
1044 skb_queue_tail(q, skb);
1048 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1050 skb_queue_tail(q, skb);
1053 /* Log rule additions and removals */
1054 static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid,
1055 char *action, struct audit_krule *rule,
1058 struct audit_buffer *ab;
1063 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1066 audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid);
1070 if (security_secid_to_secctx(sid, &ctx, &len))
1071 audit_log_format(ab, " ssid=%u", sid);
1073 audit_log_format(ab, " subj=%s", ctx);
1074 security_release_secctx(ctx, len);
1077 audit_log_format(ab, " op=");
1078 audit_log_string(ab, action);
1079 audit_log_key(ab, rule->filterkey);
1080 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1085 * audit_receive_filter - apply all rules to the specified message type
1086 * @type: audit message type
1087 * @pid: target pid for netlink audit messages
1088 * @uid: target uid for netlink audit messages
1089 * @seq: netlink audit message sequence (serial) number
1090 * @data: payload data
1091 * @datasz: size of payload data
1092 * @loginuid: loginuid of sender
1093 * @sessionid: sessionid for netlink audit message
1094 * @sid: SE Linux Security ID of sender
1096 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1097 size_t datasz, uid_t loginuid, u32 sessionid, u32 sid)
1099 struct task_struct *tsk;
1100 struct audit_netlink_list *dest;
1102 struct audit_entry *entry;
1106 case AUDIT_LIST_RULES:
1107 /* We can't just spew out the rules here because we might fill
1108 * the available socket buffer space and deadlock waiting for
1109 * auditctl to read from it... which isn't ever going to
1110 * happen if we're actually running in the context of auditctl
1111 * trying to _send_ the stuff */
1113 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1117 skb_queue_head_init(&dest->q);
1119 mutex_lock(&audit_filter_mutex);
1120 if (type == AUDIT_LIST)
1121 audit_list(pid, seq, &dest->q);
1123 audit_list_rules(pid, seq, &dest->q);
1124 mutex_unlock(&audit_filter_mutex);
1126 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1128 skb_queue_purge(&dest->q);
1134 case AUDIT_ADD_RULE:
1135 if (type == AUDIT_ADD)
1136 entry = audit_rule_to_entry(data);
1138 entry = audit_data_to_entry(data, datasz);
1140 return PTR_ERR(entry);
1142 err = audit_add_rule(entry);
1143 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1144 &entry->rule, !err);
1147 audit_free_rule(entry);
1150 case AUDIT_DEL_RULE:
1151 if (type == AUDIT_DEL)
1152 entry = audit_rule_to_entry(data);
1154 entry = audit_data_to_entry(data, datasz);
1156 return PTR_ERR(entry);
1158 err = audit_del_rule(entry);
1159 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1160 &entry->rule, !err);
1162 audit_free_rule(entry);
1171 int audit_comparator(u32 left, u32 op, u32 right)
1175 return (left == right);
1176 case Audit_not_equal:
1177 return (left != right);
1179 return (left < right);
1181 return (left <= right);
1183 return (left > right);
1185 return (left >= right);
1187 return (left & right);
1189 return ((left & right) == right);
1196 /* Compare given dentry name with last component in given path,
1197 * return of 0 indicates a match. */
1198 int audit_compare_dname_path(const char *dname, const char *path,
1204 if (!dname || !path)
1207 dlen = strlen(dname);
1208 plen = strlen(path);
1212 /* disregard trailing slashes */
1213 p = path + plen - 1;
1214 while ((*p == '/') && (p > path))
1217 /* find last path component */
1221 else if (p > path) {
1228 /* return length of path's directory component */
1231 return strncmp(p, dname, dlen);
1234 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1235 struct audit_krule *rule,
1236 enum audit_state *state)
1240 for (i = 0; i < rule->field_count; i++) {
1241 struct audit_field *f = &rule->fields[i];
1247 result = audit_comparator(cb->creds.pid, f->op, f->val);
1250 result = audit_comparator(cb->creds.uid, f->op, f->val);
1253 result = audit_comparator(cb->creds.gid, f->op, f->val);
1255 case AUDIT_LOGINUID:
1256 result = audit_comparator(audit_get_loginuid(current),
1259 case AUDIT_SUBJ_USER:
1260 case AUDIT_SUBJ_ROLE:
1261 case AUDIT_SUBJ_TYPE:
1262 case AUDIT_SUBJ_SEN:
1263 case AUDIT_SUBJ_CLR:
1265 security_task_getsecid(current, &sid);
1266 result = security_audit_rule_match(sid,
1278 switch (rule->action) {
1279 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1280 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1285 int audit_filter_user(struct netlink_skb_parms *cb)
1287 enum audit_state state = AUDIT_DISABLED;
1288 struct audit_entry *e;
1292 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1293 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1294 if (state == AUDIT_DISABLED)
1301 return ret; /* Audit by default */
1304 int audit_filter_type(int type)
1306 struct audit_entry *e;
1310 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1311 goto unlock_and_return;
1313 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1316 for (i = 0; i < e->rule.field_count; i++) {
1317 struct audit_field *f = &e->rule.fields[i];
1318 if (f->type == AUDIT_MSGTYPE) {
1319 result = audit_comparator(type, f->op, f->val);
1325 goto unlock_and_return;
1332 static int update_lsm_rule(struct audit_krule *r)
1334 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1335 struct audit_entry *nentry;
1338 if (!security_audit_rule_known(r))
1341 nentry = audit_dupe_rule(r);
1342 if (IS_ERR(nentry)) {
1343 /* save the first error encountered for the
1345 err = PTR_ERR(nentry);
1346 audit_panic("error updating LSM filters");
1348 list_del(&r->rlist);
1349 list_del_rcu(&entry->list);
1352 if (r->watch || r->tree)
1353 list_replace_init(&r->rlist, &nentry->rule.rlist);
1354 list_replace_rcu(&entry->list, &nentry->list);
1355 list_replace(&r->list, &nentry->rule.list);
1357 call_rcu(&entry->rcu, audit_free_rule_rcu);
1362 /* This function will re-initialize the lsm_rule field of all applicable rules.
1363 * It will traverse the filter lists serarching for rules that contain LSM
1364 * specific filter fields. When such a rule is found, it is copied, the
1365 * LSM field is re-initialized, and the old rule is replaced with the
1367 int audit_update_lsm_rules(void)
1369 struct audit_krule *r, *n;
1372 /* audit_filter_mutex synchronizes the writers */
1373 mutex_lock(&audit_filter_mutex);
1375 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1376 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1377 int res = update_lsm_rule(r);
1382 mutex_unlock(&audit_filter_mutex);