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 #if AUDIT_NR_FILTERS != 6
60 #error Fix audit_filter_list initialiser
63 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
64 LIST_HEAD_INIT(audit_rules_list[0]),
65 LIST_HEAD_INIT(audit_rules_list[1]),
66 LIST_HEAD_INIT(audit_rules_list[2]),
67 LIST_HEAD_INIT(audit_rules_list[3]),
68 LIST_HEAD_INIT(audit_rules_list[4]),
69 LIST_HEAD_INIT(audit_rules_list[5]),
72 DEFINE_MUTEX(audit_filter_mutex);
74 static void audit_free_lsm_field(struct audit_field *f)
85 case AUDIT_OBJ_LEV_LOW:
86 case AUDIT_OBJ_LEV_HIGH:
88 security_audit_rule_free(f->lsm_rule);
92 static inline void audit_free_rule(struct audit_entry *e)
95 struct audit_krule *erule = &e->rule;
97 /* some rules don't have associated watches */
99 audit_put_watch(erule->watch);
101 for (i = 0; i < erule->field_count; i++)
102 audit_free_lsm_field(&erule->fields[i]);
103 kfree(erule->fields);
104 kfree(erule->filterkey);
108 void audit_free_rule_rcu(struct rcu_head *head)
110 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
114 /* Initialize an audit filterlist entry. */
115 static inline struct audit_entry *audit_init_entry(u32 field_count)
117 struct audit_entry *entry;
118 struct audit_field *fields;
120 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
121 if (unlikely(!entry))
124 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
125 if (unlikely(!fields)) {
129 entry->rule.fields = fields;
134 /* Unpack a filter field's string representation from user-space
136 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
140 if (!*bufp || (len == 0) || (len > *remain))
141 return ERR_PTR(-EINVAL);
143 /* Of the currently implemented string fields, PATH_MAX
144 * defines the longest valid length.
147 return ERR_PTR(-ENAMETOOLONG);
149 str = kmalloc(len + 1, GFP_KERNEL);
151 return ERR_PTR(-ENOMEM);
153 memcpy(str, *bufp, len);
161 /* Translate an inode field to kernel representation. */
162 static inline int audit_to_inode(struct audit_krule *krule,
163 struct audit_field *f)
165 if (krule->listnr != AUDIT_FILTER_EXIT ||
166 krule->inode_f || krule->watch || krule->tree ||
167 (f->op != Audit_equal && f->op != Audit_not_equal))
174 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
176 int __init audit_register_class(int class, unsigned *list)
178 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
181 while (*list != ~0U) {
182 unsigned n = *list++;
183 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
187 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
189 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
197 int audit_match_class(int class, unsigned syscall)
199 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
201 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
203 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
206 #ifdef CONFIG_AUDITSYSCALL
207 static inline int audit_match_class_bits(int class, u32 *mask)
211 if (classes[class]) {
212 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
213 if (mask[i] & classes[class][i])
219 static int audit_match_signal(struct audit_entry *entry)
221 struct audit_field *arch = entry->rule.arch_f;
224 /* When arch is unspecified, we must check both masks on biarch
225 * as syscall number alone is ambiguous. */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
228 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
232 switch(audit_classify_arch(arch->val)) {
234 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
236 case 1: /* 32bit on biarch */
237 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
245 /* Common user-space to kernel rule translation. */
246 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
249 struct audit_entry *entry;
253 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
257 #ifdef CONFIG_AUDITSYSCALL
258 case AUDIT_FILTER_ENTRY:
259 if (rule->action == AUDIT_ALWAYS)
261 case AUDIT_FILTER_EXIT:
262 case AUDIT_FILTER_TASK:
264 case AUDIT_FILTER_USER:
265 case AUDIT_FILTER_TYPE:
268 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
269 pr_err("AUDIT_POSSIBLE is deprecated\n");
272 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
274 if (rule->field_count > AUDIT_MAX_FIELDS)
278 entry = audit_init_entry(rule->field_count);
282 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
283 entry->rule.listnr = listnr;
284 entry->rule.action = rule->action;
285 entry->rule.field_count = rule->field_count;
287 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
288 entry->rule.mask[i] = rule->mask[i];
290 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
291 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
292 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
295 if (!(*p & AUDIT_BIT(bit)))
297 *p &= ~AUDIT_BIT(bit);
301 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
302 entry->rule.mask[j] |= class[j];
312 static u32 audit_ops[] =
314 [Audit_equal] = AUDIT_EQUAL,
315 [Audit_not_equal] = AUDIT_NOT_EQUAL,
316 [Audit_bitmask] = AUDIT_BIT_MASK,
317 [Audit_bittest] = AUDIT_BIT_TEST,
318 [Audit_lt] = AUDIT_LESS_THAN,
319 [Audit_gt] = AUDIT_GREATER_THAN,
320 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
321 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
324 static u32 audit_to_op(u32 op)
327 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
332 /* check if an audit field is valid */
333 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
337 if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
338 entry->rule.listnr != AUDIT_FILTER_USER)
366 case AUDIT_SESSIONID:
367 /* bit ops are only useful on syscall args */
368 if (f->op == Audit_bitmask || f->op == Audit_bittest)
375 case AUDIT_SUBJ_USER:
376 case AUDIT_SUBJ_ROLE:
377 case AUDIT_SUBJ_TYPE:
383 case AUDIT_OBJ_LEV_LOW:
384 case AUDIT_OBJ_LEV_HIGH:
387 case AUDIT_FILTERKEY:
389 case AUDIT_LOGINUID_SET:
390 if ((f->val != 0) && (f->val != 1))
394 if (f->op != Audit_not_equal && f->op != Audit_equal)
402 if (f->val & ~S_IFMT)
405 case AUDIT_FIELD_COMPARE:
406 if (f->val > AUDIT_MAX_FIELD_COMPARE)
410 if (f->op != Audit_not_equal && f->op != Audit_equal)
412 if (entry->rule.listnr != AUDIT_FILTER_EXIT)
419 /* Translate struct audit_rule_data to kernel's rule representation. */
420 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
424 struct audit_entry *entry;
426 size_t remain = datasz - sizeof(struct audit_rule_data);
429 struct audit_fsnotify_mark *audit_mark;
431 entry = audit_to_entry_common(data);
436 for (i = 0; i < data->field_count; i++) {
437 struct audit_field *f = &entry->rule.fields[i];
442 f->op = audit_to_op(data->fieldflags[i]);
443 if (f->op == Audit_bad)
446 f->type = data->fields[i];
447 f_val = data->values[i];
449 /* Support legacy tests for a valid loginuid */
450 if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
451 f->type = AUDIT_LOGINUID_SET;
453 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
456 err = audit_field_valid(entry, f);
468 f->uid = make_kuid(current_user_ns(), f_val);
469 if (!uid_valid(f->uid))
477 f->gid = make_kgid(current_user_ns(), f_val);
478 if (!gid_valid(f->gid))
481 case AUDIT_SESSIONID:
484 entry->rule.arch_f = f;
486 case AUDIT_SUBJ_USER:
487 case AUDIT_SUBJ_ROLE:
488 case AUDIT_SUBJ_TYPE:
494 case AUDIT_OBJ_LEV_LOW:
495 case AUDIT_OBJ_LEV_HIGH:
496 str = audit_unpack_string(&bufp, &remain, f_val);
501 entry->rule.buflen += f_val;
503 err = security_audit_rule_init(f->type, f->op, str,
504 (void **)&f->lsm_rule);
505 /* Keep currently invalid fields around in case they
506 * become valid after a policy reload. */
507 if (err == -EINVAL) {
508 pr_warn("audit rule for LSM \'%s\' is invalid\n",
515 str = audit_unpack_string(&bufp, &remain, f_val);
520 err = audit_to_watch(&entry->rule, str, f_val, f->op);
525 entry->rule.buflen += f_val;
528 str = audit_unpack_string(&bufp, &remain, f_val);
533 err = audit_make_tree(&entry->rule, str, f->op);
537 entry->rule.buflen += f_val;
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);
553 entry->rule.buflen += f_val;
554 entry->rule.filterkey = str;
557 if (entry->rule.exe || f_val > PATH_MAX)
559 str = audit_unpack_string(&bufp, &remain, 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.buflen += f_val;
571 entry->rule.exe = audit_mark;
579 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
580 entry->rule.inode_f = NULL;
586 if (entry->rule.tree)
587 audit_put_tree(entry->rule.tree); /* that's the temporary one */
589 audit_remove_mark(entry->rule.exe); /* that's the template one */
590 audit_free_rule(entry);
594 /* Pack a filter field's string representation into data block. */
595 static inline size_t audit_pack_string(void **bufp, const char *str)
597 size_t len = strlen(str);
599 memcpy(*bufp, str, len);
605 /* Translate kernel rule representation to struct audit_rule_data. */
606 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
608 struct audit_rule_data *data;
612 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
615 memset(data, 0, sizeof(*data));
617 data->flags = krule->flags | krule->listnr;
618 data->action = krule->action;
619 data->field_count = krule->field_count;
621 for (i = 0; i < data->field_count; i++) {
622 struct audit_field *f = &krule->fields[i];
624 data->fields[i] = f->type;
625 data->fieldflags[i] = audit_ops[f->op];
627 case AUDIT_SUBJ_USER:
628 case AUDIT_SUBJ_ROLE:
629 case AUDIT_SUBJ_TYPE:
635 case AUDIT_OBJ_LEV_LOW:
636 case AUDIT_OBJ_LEV_HIGH:
637 data->buflen += data->values[i] =
638 audit_pack_string(&bufp, f->lsm_str);
641 data->buflen += data->values[i] =
642 audit_pack_string(&bufp,
643 audit_watch_path(krule->watch));
646 data->buflen += data->values[i] =
647 audit_pack_string(&bufp,
648 audit_tree_path(krule->tree));
650 case AUDIT_FILTERKEY:
651 data->buflen += data->values[i] =
652 audit_pack_string(&bufp, krule->filterkey);
655 data->buflen += data->values[i] =
656 audit_pack_string(&bufp, audit_mark_path(krule->exe));
658 case AUDIT_LOGINUID_SET:
659 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
660 data->fields[i] = AUDIT_LOGINUID;
661 data->values[i] = AUDIT_UID_UNSET;
664 /* fallthrough if set */
666 data->values[i] = f->val;
669 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
674 /* Compare two rules in kernel format. Considered success if rules
676 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
680 if (a->flags != b->flags ||
681 a->pflags != b->pflags ||
682 a->listnr != b->listnr ||
683 a->action != b->action ||
684 a->field_count != b->field_count)
687 for (i = 0; i < a->field_count; i++) {
688 if (a->fields[i].type != b->fields[i].type ||
689 a->fields[i].op != b->fields[i].op)
692 switch(a->fields[i].type) {
693 case AUDIT_SUBJ_USER:
694 case AUDIT_SUBJ_ROLE:
695 case AUDIT_SUBJ_TYPE:
701 case AUDIT_OBJ_LEV_LOW:
702 case AUDIT_OBJ_LEV_HIGH:
703 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
707 if (strcmp(audit_watch_path(a->watch),
708 audit_watch_path(b->watch)))
712 if (strcmp(audit_tree_path(a->tree),
713 audit_tree_path(b->tree)))
716 case AUDIT_FILTERKEY:
717 /* both filterkeys exist based on above type compare */
718 if (strcmp(a->filterkey, b->filterkey))
722 /* both paths exist based on above type compare */
723 if (strcmp(audit_mark_path(a->exe),
724 audit_mark_path(b->exe)))
733 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
741 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
745 if (a->fields[i].val != b->fields[i].val)
750 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
751 if (a->mask[i] != b->mask[i])
757 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
759 static inline int audit_dupe_lsm_field(struct audit_field *df,
760 struct audit_field *sf)
765 /* our own copy of lsm_str */
766 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
767 if (unlikely(!lsm_str))
769 df->lsm_str = lsm_str;
771 /* our own (refreshed) copy of lsm_rule */
772 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
773 (void **)&df->lsm_rule);
774 /* Keep currently invalid fields around in case they
775 * become valid after a policy reload. */
776 if (ret == -EINVAL) {
777 pr_warn("audit rule for LSM \'%s\' is invalid\n",
785 /* Duplicate an audit rule. This will be a deep copy with the exception
786 * of the watch - that pointer is carried over. The LSM specific fields
787 * will be updated in the copy. The point is to be able to replace the old
788 * rule with the new rule in the filterlist, then free the old rule.
789 * The rlist element is undefined; list manipulations are handled apart from
790 * the initial copy. */
791 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
793 u32 fcount = old->field_count;
794 struct audit_entry *entry;
795 struct audit_krule *new;
799 entry = audit_init_entry(fcount);
800 if (unlikely(!entry))
801 return ERR_PTR(-ENOMEM);
804 new->flags = old->flags;
805 new->pflags = old->pflags;
806 new->listnr = old->listnr;
807 new->action = old->action;
808 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
809 new->mask[i] = old->mask[i];
810 new->prio = old->prio;
811 new->buflen = old->buflen;
812 new->inode_f = old->inode_f;
813 new->field_count = old->field_count;
816 * note that we are OK with not refcounting here; audit_match_tree()
817 * never dereferences tree and we can't get false positives there
818 * since we'd have to have rule gone from the list *and* removed
819 * before the chunks found by lookup had been allocated, i.e. before
820 * the beginning of list scan.
822 new->tree = old->tree;
823 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
825 /* deep copy this information, updating the lsm_rule fields, because
826 * the originals will all be freed when the old rule is freed. */
827 for (i = 0; i < fcount; i++) {
828 switch (new->fields[i].type) {
829 case AUDIT_SUBJ_USER:
830 case AUDIT_SUBJ_ROLE:
831 case AUDIT_SUBJ_TYPE:
837 case AUDIT_OBJ_LEV_LOW:
838 case AUDIT_OBJ_LEV_HIGH:
839 err = audit_dupe_lsm_field(&new->fields[i],
842 case AUDIT_FILTERKEY:
843 fk = kstrdup(old->filterkey, GFP_KERNEL);
850 err = audit_dupe_exe(new, old);
855 audit_remove_mark(new->exe);
856 audit_free_rule(entry);
862 audit_get_watch(old->watch);
863 new->watch = old->watch;
869 /* Find an existing audit rule.
870 * Caller must hold audit_filter_mutex to prevent stale rule data. */
871 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
872 struct list_head **p)
874 struct audit_entry *e, *found = NULL;
875 struct list_head *list;
878 if (entry->rule.inode_f) {
879 h = audit_hash_ino(entry->rule.inode_f->val);
880 *p = list = &audit_inode_hash[h];
881 } else if (entry->rule.watch) {
882 /* we don't know the inode number, so must walk entire hash */
883 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
884 list = &audit_inode_hash[h];
885 list_for_each_entry(e, list, list)
886 if (!audit_compare_rule(&entry->rule, &e->rule)) {
893 *p = list = &audit_filter_list[entry->rule.listnr];
896 list_for_each_entry(e, list, list)
897 if (!audit_compare_rule(&entry->rule, &e->rule)) {
906 static u64 prio_low = ~0ULL/2;
907 static u64 prio_high = ~0ULL/2 - 1;
909 /* Add rule to given filterlist if not a duplicate. */
910 static inline int audit_add_rule(struct audit_entry *entry)
912 struct audit_entry *e;
913 struct audit_watch *watch = entry->rule.watch;
914 struct audit_tree *tree = entry->rule.tree;
915 struct list_head *list;
917 #ifdef CONFIG_AUDITSYSCALL
920 /* If either of these, don't count towards total */
921 if (entry->rule.listnr == AUDIT_FILTER_USER ||
922 entry->rule.listnr == AUDIT_FILTER_TYPE)
926 mutex_lock(&audit_filter_mutex);
927 e = audit_find_rule(entry, &list);
929 mutex_unlock(&audit_filter_mutex);
931 /* normally audit_add_tree_rule() will free it on failure */
933 audit_put_tree(tree);
938 /* audit_filter_mutex is dropped and re-taken during this call */
939 err = audit_add_watch(&entry->rule, &list);
941 mutex_unlock(&audit_filter_mutex);
943 * normally audit_add_tree_rule() will free it
947 audit_put_tree(tree);
952 err = audit_add_tree_rule(&entry->rule);
954 mutex_unlock(&audit_filter_mutex);
959 entry->rule.prio = ~0ULL;
960 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
961 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
962 entry->rule.prio = ++prio_high;
964 entry->rule.prio = --prio_low;
967 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
968 list_add(&entry->rule.list,
969 &audit_rules_list[entry->rule.listnr]);
970 list_add_rcu(&entry->list, list);
971 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
973 list_add_tail(&entry->rule.list,
974 &audit_rules_list[entry->rule.listnr]);
975 list_add_tail_rcu(&entry->list, list);
977 #ifdef CONFIG_AUDITSYSCALL
981 if (!audit_match_signal(entry))
984 mutex_unlock(&audit_filter_mutex);
989 /* Remove an existing rule from filterlist. */
990 int audit_del_rule(struct audit_entry *entry)
992 struct audit_entry *e;
993 struct audit_tree *tree = entry->rule.tree;
994 struct list_head *list;
996 #ifdef CONFIG_AUDITSYSCALL
999 /* If either of these, don't count towards total */
1000 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1001 entry->rule.listnr == AUDIT_FILTER_TYPE)
1005 mutex_lock(&audit_filter_mutex);
1006 e = audit_find_rule(entry, &list);
1013 audit_remove_watch_rule(&e->rule);
1016 audit_remove_tree_rule(&e->rule);
1019 audit_remove_mark_rule(&e->rule);
1021 #ifdef CONFIG_AUDITSYSCALL
1025 if (!audit_match_signal(entry))
1029 list_del_rcu(&e->list);
1030 list_del(&e->rule.list);
1031 call_rcu(&e->rcu, audit_free_rule_rcu);
1034 mutex_unlock(&audit_filter_mutex);
1037 audit_put_tree(tree); /* that's the temporary one */
1042 /* List rules using struct audit_rule_data. */
1043 static void audit_list_rules(int seq, struct sk_buff_head *q)
1045 struct sk_buff *skb;
1046 struct audit_krule *r;
1049 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1050 * iterator to sync with list writers. */
1051 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1052 list_for_each_entry(r, &audit_rules_list[i], list) {
1053 struct audit_rule_data *data;
1055 data = audit_krule_to_data(r);
1056 if (unlikely(!data))
1058 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1060 sizeof(*data) + data->buflen);
1062 skb_queue_tail(q, skb);
1066 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1068 skb_queue_tail(q, skb);
1071 /* Log rule additions and removals */
1072 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1074 struct audit_buffer *ab;
1075 uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1076 unsigned int sessionid = audit_get_sessionid(current);
1081 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1084 audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid);
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 struct task_struct *tsk;
1141 struct audit_netlink_list *dest;
1143 /* We can't just spew out the rules here because we might fill
1144 * the available socket buffer space and deadlock waiting for
1145 * auditctl to read from it... which isn't ever going to
1146 * happen if we're actually running in the context of auditctl
1147 * trying to _send_ the stuff */
1149 dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1152 dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1153 dest->portid = NETLINK_CB(request_skb).portid;
1154 skb_queue_head_init(&dest->q);
1156 mutex_lock(&audit_filter_mutex);
1157 audit_list_rules(seq, &dest->q);
1158 mutex_unlock(&audit_filter_mutex);
1160 tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1162 skb_queue_purge(&dest->q);
1165 return PTR_ERR(tsk);
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 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1200 return uid_eq(left, right);
1201 case Audit_not_equal:
1202 return !uid_eq(left, right);
1204 return uid_lt(left, right);
1206 return uid_lte(left, right);
1208 return uid_gt(left, right);
1210 return uid_gte(left, right);
1219 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1223 return gid_eq(left, right);
1224 case Audit_not_equal:
1225 return !gid_eq(left, right);
1227 return gid_lt(left, right);
1229 return gid_lte(left, right);
1231 return gid_gt(left, right);
1233 return gid_gte(left, right);
1243 * parent_len - find the length of the parent portion of a pathname
1244 * @path: pathname of which to determine length
1246 int parent_len(const char *path)
1251 plen = strlen(path);
1256 /* disregard trailing slashes */
1257 p = path + plen - 1;
1258 while ((*p == '/') && (p > path))
1261 /* walk backward until we find the next slash or hit beginning */
1262 while ((*p != '/') && (p > path))
1265 /* did we find a slash? Then increment to include it in path */
1273 * audit_compare_dname_path - compare given dentry name with last component in
1274 * given path. Return of 0 indicates a match.
1275 * @dname: dentry name that we're comparing
1276 * @path: full pathname that we're comparing
1277 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1278 * here indicates that we must compute this value.
1280 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1285 dlen = strlen(dname);
1286 pathlen = strlen(path);
1290 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1291 if (pathlen - parentlen != dlen)
1294 p = path + parentlen;
1296 return strncmp(p, dname, dlen);
1299 int audit_filter(int msgtype, unsigned int listtype)
1301 struct audit_entry *e;
1302 int ret = 1; /* Audit by default */
1305 if (list_empty(&audit_filter_list[listtype]))
1306 goto unlock_and_return;
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, NULL);
1349 goto unlock_and_return;
1351 if (result < 0) /* error */
1352 goto unlock_and_return;
1357 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_TYPE)
1367 static int update_lsm_rule(struct audit_krule *r)
1369 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1370 struct audit_entry *nentry;
1373 if (!security_audit_rule_known(r))
1376 nentry = audit_dupe_rule(r);
1377 if (entry->rule.exe)
1378 audit_remove_mark(entry->rule.exe);
1379 if (IS_ERR(nentry)) {
1380 /* save the first error encountered for the
1382 err = PTR_ERR(nentry);
1383 audit_panic("error updating LSM filters");
1385 list_del(&r->rlist);
1386 list_del_rcu(&entry->list);
1389 if (r->watch || r->tree)
1390 list_replace_init(&r->rlist, &nentry->rule.rlist);
1391 list_replace_rcu(&entry->list, &nentry->list);
1392 list_replace(&r->list, &nentry->rule.list);
1394 call_rcu(&entry->rcu, audit_free_rule_rcu);
1399 /* This function will re-initialize the lsm_rule field of all applicable rules.
1400 * It will traverse the filter lists serarching for rules that contain LSM
1401 * specific filter fields. When such a rule is found, it is copied, the
1402 * LSM field is re-initialized, and the old rule is replaced with the
1404 int audit_update_lsm_rules(void)
1406 struct audit_krule *r, *n;
1409 /* audit_filter_mutex synchronizes the writers */
1410 mutex_lock(&audit_filter_mutex);
1412 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1413 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1414 int res = update_lsm_rule(r);
1419 mutex_unlock(&audit_filter_mutex);