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 /* bit ops are only useful on syscall args */
367 if (f->op == Audit_bitmask || f->op == Audit_bittest)
374 case AUDIT_SUBJ_USER:
375 case AUDIT_SUBJ_ROLE:
376 case AUDIT_SUBJ_TYPE:
382 case AUDIT_OBJ_LEV_LOW:
383 case AUDIT_OBJ_LEV_HIGH:
386 case AUDIT_FILTERKEY:
388 case AUDIT_LOGINUID_SET:
389 if ((f->val != 0) && (f->val != 1))
393 if (f->op != Audit_not_equal && f->op != Audit_equal)
401 if (f->val & ~S_IFMT)
404 case AUDIT_FIELD_COMPARE:
405 if (f->val > AUDIT_MAX_FIELD_COMPARE)
409 if (f->op != Audit_equal)
411 if (entry->rule.listnr != AUDIT_FILTER_EXIT)
418 /* Translate struct audit_rule_data to kernel's rule representation. */
419 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
423 struct audit_entry *entry;
425 size_t remain = datasz - sizeof(struct audit_rule_data);
428 struct audit_fsnotify_mark *audit_mark;
430 entry = audit_to_entry_common(data);
435 for (i = 0; i < data->field_count; i++) {
436 struct audit_field *f = &entry->rule.fields[i];
440 f->op = audit_to_op(data->fieldflags[i]);
441 if (f->op == Audit_bad)
444 f->type = data->fields[i];
445 f->val = data->values[i];
447 /* Support legacy tests for a valid loginuid */
448 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
449 f->type = AUDIT_LOGINUID_SET;
451 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
454 err = audit_field_valid(entry, f);
466 f->uid = make_kuid(current_user_ns(), f->val);
467 if (!uid_valid(f->uid))
475 f->gid = make_kgid(current_user_ns(), f->val);
476 if (!gid_valid(f->gid))
480 entry->rule.arch_f = f;
482 case AUDIT_SUBJ_USER:
483 case AUDIT_SUBJ_ROLE:
484 case AUDIT_SUBJ_TYPE:
490 case AUDIT_OBJ_LEV_LOW:
491 case AUDIT_OBJ_LEV_HIGH:
492 str = audit_unpack_string(&bufp, &remain, f->val);
495 entry->rule.buflen += f->val;
497 err = security_audit_rule_init(f->type, f->op, str,
498 (void **)&f->lsm_rule);
499 /* Keep currently invalid fields around in case they
500 * become valid after a policy reload. */
501 if (err == -EINVAL) {
502 pr_warn("audit rule for LSM \'%s\' is invalid\n",
513 str = audit_unpack_string(&bufp, &remain, f->val);
516 entry->rule.buflen += f->val;
518 err = audit_to_watch(&entry->rule, str, f->val, f->op);
525 str = audit_unpack_string(&bufp, &remain, f->val);
528 entry->rule.buflen += f->val;
530 err = audit_make_tree(&entry->rule, str, f->op);
536 err = audit_to_inode(&entry->rule, f);
540 case AUDIT_FILTERKEY:
541 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
543 str = audit_unpack_string(&bufp, &remain, f->val);
546 entry->rule.buflen += f->val;
547 entry->rule.filterkey = str;
550 if (entry->rule.exe || f->val > PATH_MAX)
552 str = audit_unpack_string(&bufp, &remain, f->val);
557 entry->rule.buflen += f->val;
559 audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
560 if (IS_ERR(audit_mark)) {
562 err = PTR_ERR(audit_mark);
565 entry->rule.exe = audit_mark;
570 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
571 entry->rule.inode_f = NULL;
577 if (entry->rule.tree)
578 audit_put_tree(entry->rule.tree); /* that's the temporary one */
580 audit_remove_mark(entry->rule.exe); /* that's the template one */
581 audit_free_rule(entry);
585 /* Pack a filter field's string representation into data block. */
586 static inline size_t audit_pack_string(void **bufp, const char *str)
588 size_t len = strlen(str);
590 memcpy(*bufp, str, len);
596 /* Translate kernel rule representation to struct audit_rule_data. */
597 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
599 struct audit_rule_data *data;
603 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
606 memset(data, 0, sizeof(*data));
608 data->flags = krule->flags | krule->listnr;
609 data->action = krule->action;
610 data->field_count = krule->field_count;
612 for (i = 0; i < data->field_count; i++) {
613 struct audit_field *f = &krule->fields[i];
615 data->fields[i] = f->type;
616 data->fieldflags[i] = audit_ops[f->op];
618 case AUDIT_SUBJ_USER:
619 case AUDIT_SUBJ_ROLE:
620 case AUDIT_SUBJ_TYPE:
626 case AUDIT_OBJ_LEV_LOW:
627 case AUDIT_OBJ_LEV_HIGH:
628 data->buflen += data->values[i] =
629 audit_pack_string(&bufp, f->lsm_str);
632 data->buflen += data->values[i] =
633 audit_pack_string(&bufp,
634 audit_watch_path(krule->watch));
637 data->buflen += data->values[i] =
638 audit_pack_string(&bufp,
639 audit_tree_path(krule->tree));
641 case AUDIT_FILTERKEY:
642 data->buflen += data->values[i] =
643 audit_pack_string(&bufp, krule->filterkey);
646 data->buflen += data->values[i] =
647 audit_pack_string(&bufp, audit_mark_path(krule->exe));
649 case AUDIT_LOGINUID_SET:
650 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
651 data->fields[i] = AUDIT_LOGINUID;
652 data->values[i] = AUDIT_UID_UNSET;
655 /* fallthrough if set */
657 data->values[i] = f->val;
660 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
665 /* Compare two rules in kernel format. Considered success if rules
667 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
671 if (a->flags != b->flags ||
672 a->pflags != b->pflags ||
673 a->listnr != b->listnr ||
674 a->action != b->action ||
675 a->field_count != b->field_count)
678 for (i = 0; i < a->field_count; i++) {
679 if (a->fields[i].type != b->fields[i].type ||
680 a->fields[i].op != b->fields[i].op)
683 switch(a->fields[i].type) {
684 case AUDIT_SUBJ_USER:
685 case AUDIT_SUBJ_ROLE:
686 case AUDIT_SUBJ_TYPE:
692 case AUDIT_OBJ_LEV_LOW:
693 case AUDIT_OBJ_LEV_HIGH:
694 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
698 if (strcmp(audit_watch_path(a->watch),
699 audit_watch_path(b->watch)))
703 if (strcmp(audit_tree_path(a->tree),
704 audit_tree_path(b->tree)))
707 case AUDIT_FILTERKEY:
708 /* both filterkeys exist based on above type compare */
709 if (strcmp(a->filterkey, b->filterkey))
713 /* both paths exist based on above type compare */
714 if (strcmp(audit_mark_path(a->exe),
715 audit_mark_path(b->exe)))
724 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
732 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
736 if (a->fields[i].val != b->fields[i].val)
741 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
742 if (a->mask[i] != b->mask[i])
748 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
750 static inline int audit_dupe_lsm_field(struct audit_field *df,
751 struct audit_field *sf)
756 /* our own copy of lsm_str */
757 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
758 if (unlikely(!lsm_str))
760 df->lsm_str = lsm_str;
762 /* our own (refreshed) copy of lsm_rule */
763 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
764 (void **)&df->lsm_rule);
765 /* Keep currently invalid fields around in case they
766 * become valid after a policy reload. */
767 if (ret == -EINVAL) {
768 pr_warn("audit rule for LSM \'%s\' is invalid\n",
776 /* Duplicate an audit rule. This will be a deep copy with the exception
777 * of the watch - that pointer is carried over. The LSM specific fields
778 * will be updated in the copy. The point is to be able to replace the old
779 * rule with the new rule in the filterlist, then free the old rule.
780 * The rlist element is undefined; list manipulations are handled apart from
781 * the initial copy. */
782 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
784 u32 fcount = old->field_count;
785 struct audit_entry *entry;
786 struct audit_krule *new;
790 entry = audit_init_entry(fcount);
791 if (unlikely(!entry))
792 return ERR_PTR(-ENOMEM);
795 new->flags = old->flags;
796 new->pflags = old->pflags;
797 new->listnr = old->listnr;
798 new->action = old->action;
799 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
800 new->mask[i] = old->mask[i];
801 new->prio = old->prio;
802 new->buflen = old->buflen;
803 new->inode_f = old->inode_f;
804 new->field_count = old->field_count;
807 * note that we are OK with not refcounting here; audit_match_tree()
808 * never dereferences tree and we can't get false positives there
809 * since we'd have to have rule gone from the list *and* removed
810 * before the chunks found by lookup had been allocated, i.e. before
811 * the beginning of list scan.
813 new->tree = old->tree;
814 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
816 /* deep copy this information, updating the lsm_rule fields, because
817 * the originals will all be freed when the old rule is freed. */
818 for (i = 0; i < fcount; i++) {
819 switch (new->fields[i].type) {
820 case AUDIT_SUBJ_USER:
821 case AUDIT_SUBJ_ROLE:
822 case AUDIT_SUBJ_TYPE:
828 case AUDIT_OBJ_LEV_LOW:
829 case AUDIT_OBJ_LEV_HIGH:
830 err = audit_dupe_lsm_field(&new->fields[i],
833 case AUDIT_FILTERKEY:
834 fk = kstrdup(old->filterkey, GFP_KERNEL);
841 err = audit_dupe_exe(new, old);
846 audit_remove_mark(new->exe);
847 audit_free_rule(entry);
853 audit_get_watch(old->watch);
854 new->watch = old->watch;
860 /* Find an existing audit rule.
861 * Caller must hold audit_filter_mutex to prevent stale rule data. */
862 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
863 struct list_head **p)
865 struct audit_entry *e, *found = NULL;
866 struct list_head *list;
869 if (entry->rule.inode_f) {
870 h = audit_hash_ino(entry->rule.inode_f->val);
871 *p = list = &audit_inode_hash[h];
872 } else if (entry->rule.watch) {
873 /* we don't know the inode number, so must walk entire hash */
874 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
875 list = &audit_inode_hash[h];
876 list_for_each_entry(e, list, list)
877 if (!audit_compare_rule(&entry->rule, &e->rule)) {
884 *p = list = &audit_filter_list[entry->rule.listnr];
887 list_for_each_entry(e, list, list)
888 if (!audit_compare_rule(&entry->rule, &e->rule)) {
897 static u64 prio_low = ~0ULL/2;
898 static u64 prio_high = ~0ULL/2 - 1;
900 /* Add rule to given filterlist if not a duplicate. */
901 static inline int audit_add_rule(struct audit_entry *entry)
903 struct audit_entry *e;
904 struct audit_watch *watch = entry->rule.watch;
905 struct audit_tree *tree = entry->rule.tree;
906 struct list_head *list;
908 #ifdef CONFIG_AUDITSYSCALL
911 /* If either of these, don't count towards total */
912 if (entry->rule.listnr == AUDIT_FILTER_USER ||
913 entry->rule.listnr == AUDIT_FILTER_TYPE)
917 mutex_lock(&audit_filter_mutex);
918 e = audit_find_rule(entry, &list);
920 mutex_unlock(&audit_filter_mutex);
922 /* normally audit_add_tree_rule() will free it on failure */
924 audit_put_tree(tree);
929 /* audit_filter_mutex is dropped and re-taken during this call */
930 err = audit_add_watch(&entry->rule, &list);
932 mutex_unlock(&audit_filter_mutex);
934 * normally audit_add_tree_rule() will free it
938 audit_put_tree(tree);
943 err = audit_add_tree_rule(&entry->rule);
945 mutex_unlock(&audit_filter_mutex);
950 entry->rule.prio = ~0ULL;
951 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
952 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
953 entry->rule.prio = ++prio_high;
955 entry->rule.prio = --prio_low;
958 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
959 list_add(&entry->rule.list,
960 &audit_rules_list[entry->rule.listnr]);
961 list_add_rcu(&entry->list, list);
962 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
964 list_add_tail(&entry->rule.list,
965 &audit_rules_list[entry->rule.listnr]);
966 list_add_tail_rcu(&entry->list, list);
968 #ifdef CONFIG_AUDITSYSCALL
972 if (!audit_match_signal(entry))
975 mutex_unlock(&audit_filter_mutex);
980 /* Remove an existing rule from filterlist. */
981 int audit_del_rule(struct audit_entry *entry)
983 struct audit_entry *e;
984 struct audit_tree *tree = entry->rule.tree;
985 struct list_head *list;
987 #ifdef CONFIG_AUDITSYSCALL
990 /* If either of these, don't count towards total */
991 if (entry->rule.listnr == AUDIT_FILTER_USER ||
992 entry->rule.listnr == AUDIT_FILTER_TYPE)
996 mutex_lock(&audit_filter_mutex);
997 e = audit_find_rule(entry, &list);
1004 audit_remove_watch_rule(&e->rule);
1007 audit_remove_tree_rule(&e->rule);
1010 audit_remove_mark_rule(&e->rule);
1012 #ifdef CONFIG_AUDITSYSCALL
1016 if (!audit_match_signal(entry))
1020 list_del_rcu(&e->list);
1021 list_del(&e->rule.list);
1022 call_rcu(&e->rcu, audit_free_rule_rcu);
1025 mutex_unlock(&audit_filter_mutex);
1028 audit_put_tree(tree); /* that's the temporary one */
1033 /* List rules using struct audit_rule_data. */
1034 static void audit_list_rules(__u32 portid, int seq, struct sk_buff_head *q)
1036 struct sk_buff *skb;
1037 struct audit_krule *r;
1040 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1041 * iterator to sync with list writers. */
1042 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1043 list_for_each_entry(r, &audit_rules_list[i], list) {
1044 struct audit_rule_data *data;
1046 data = audit_krule_to_data(r);
1047 if (unlikely(!data))
1049 skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES,
1051 sizeof(*data) + data->buflen);
1053 skb_queue_tail(q, skb);
1057 skb = audit_make_reply(portid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1059 skb_queue_tail(q, skb);
1062 /* Log rule additions and removals */
1063 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1065 struct audit_buffer *ab;
1066 uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1067 unsigned int sessionid = audit_get_sessionid(current);
1072 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1075 audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid);
1076 audit_log_task_context(ab);
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_rule_change - apply all rules to the specified message type
1086 * @type: audit message type
1087 * @portid: target port id for netlink audit messages
1088 * @seq: netlink audit message sequence (serial) number
1089 * @data: payload data
1090 * @datasz: size of payload data
1092 int audit_rule_change(int type, __u32 portid, int seq, void *data,
1096 struct audit_entry *entry;
1098 entry = audit_data_to_entry(data, datasz);
1100 return PTR_ERR(entry);
1103 case AUDIT_ADD_RULE:
1104 err = audit_add_rule(entry);
1105 audit_log_rule_change("add_rule", &entry->rule, !err);
1107 case AUDIT_DEL_RULE:
1108 err = audit_del_rule(entry);
1109 audit_log_rule_change("remove_rule", &entry->rule, !err);
1116 if (err || type == AUDIT_DEL_RULE) {
1117 if (entry->rule.exe)
1118 audit_remove_mark(entry->rule.exe);
1119 audit_free_rule(entry);
1126 * audit_list_rules_send - list the audit rules
1127 * @request_skb: skb of request we are replying to (used to target the reply)
1128 * @seq: netlink audit message sequence (serial) number
1130 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1132 u32 portid = NETLINK_CB(request_skb).portid;
1133 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1134 struct task_struct *tsk;
1135 struct audit_netlink_list *dest;
1138 /* We can't just spew out the rules here because we might fill
1139 * the available socket buffer space and deadlock waiting for
1140 * auditctl to read from it... which isn't ever going to
1141 * happen if we're actually running in the context of auditctl
1142 * trying to _send_ the stuff */
1144 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1147 dest->net = get_net(net);
1148 dest->portid = portid;
1149 skb_queue_head_init(&dest->q);
1151 mutex_lock(&audit_filter_mutex);
1152 audit_list_rules(portid, seq, &dest->q);
1153 mutex_unlock(&audit_filter_mutex);
1155 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1157 skb_queue_purge(&dest->q);
1165 int audit_comparator(u32 left, u32 op, u32 right)
1169 return (left == right);
1170 case Audit_not_equal:
1171 return (left != right);
1173 return (left < right);
1175 return (left <= right);
1177 return (left > right);
1179 return (left >= right);
1181 return (left & right);
1183 return ((left & right) == right);
1190 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1194 return uid_eq(left, right);
1195 case Audit_not_equal:
1196 return !uid_eq(left, right);
1198 return uid_lt(left, right);
1200 return uid_lte(left, right);
1202 return uid_gt(left, right);
1204 return uid_gte(left, right);
1213 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1217 return gid_eq(left, right);
1218 case Audit_not_equal:
1219 return !gid_eq(left, right);
1221 return gid_lt(left, right);
1223 return gid_lte(left, right);
1225 return gid_gt(left, right);
1227 return gid_gte(left, right);
1237 * parent_len - find the length of the parent portion of a pathname
1238 * @path: pathname of which to determine length
1240 int parent_len(const char *path)
1245 plen = strlen(path);
1250 /* disregard trailing slashes */
1251 p = path + plen - 1;
1252 while ((*p == '/') && (p > path))
1255 /* walk backward until we find the next slash or hit beginning */
1256 while ((*p != '/') && (p > path))
1259 /* did we find a slash? Then increment to include it in path */
1267 * audit_compare_dname_path - compare given dentry name with last component in
1268 * given path. Return of 0 indicates a match.
1269 * @dname: dentry name that we're comparing
1270 * @path: full pathname that we're comparing
1271 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1272 * here indicates that we must compute this value.
1274 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1279 dlen = strlen(dname);
1280 pathlen = strlen(path);
1284 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1285 if (pathlen - parentlen != dlen)
1288 p = path + parentlen;
1290 return strncmp(p, dname, dlen);
1293 static int audit_filter_user_rules(struct audit_krule *rule, int type,
1294 enum audit_state *state)
1298 for (i = 0; i < rule->field_count; i++) {
1299 struct audit_field *f = &rule->fields[i];
1306 pid = task_pid_nr(current);
1307 result = audit_comparator(pid, f->op, f->val);
1310 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1313 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1315 case AUDIT_LOGINUID:
1316 result = audit_uid_comparator(audit_get_loginuid(current),
1319 case AUDIT_LOGINUID_SET:
1320 result = audit_comparator(audit_loginuid_set(current),
1324 result = audit_comparator(type, f->op, f->val);
1326 case AUDIT_SUBJ_USER:
1327 case AUDIT_SUBJ_ROLE:
1328 case AUDIT_SUBJ_TYPE:
1329 case AUDIT_SUBJ_SEN:
1330 case AUDIT_SUBJ_CLR:
1332 security_task_getsecid(current, &sid);
1333 result = security_audit_rule_match(sid,
1345 switch (rule->action) {
1346 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1347 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1352 int audit_filter_user(int type)
1354 enum audit_state state = AUDIT_DISABLED;
1355 struct audit_entry *e;
1358 ret = 1; /* Audit by default */
1361 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1362 rc = audit_filter_user_rules(&e->rule, type, &state);
1364 if (rc > 0 && state == AUDIT_DISABLED)
1374 int audit_filter_type(int type)
1376 struct audit_entry *e;
1380 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1381 goto unlock_and_return;
1383 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1386 for (i = 0; i < e->rule.field_count; i++) {
1387 struct audit_field *f = &e->rule.fields[i];
1388 if (f->type == AUDIT_MSGTYPE) {
1389 result = audit_comparator(type, f->op, f->val);
1395 goto unlock_and_return;
1402 static int update_lsm_rule(struct audit_krule *r)
1404 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1405 struct audit_entry *nentry;
1408 if (!security_audit_rule_known(r))
1411 nentry = audit_dupe_rule(r);
1412 if (entry->rule.exe)
1413 audit_remove_mark(entry->rule.exe);
1414 if (IS_ERR(nentry)) {
1415 /* save the first error encountered for the
1417 err = PTR_ERR(nentry);
1418 audit_panic("error updating LSM filters");
1420 list_del(&r->rlist);
1421 list_del_rcu(&entry->list);
1424 if (r->watch || r->tree)
1425 list_replace_init(&r->rlist, &nentry->rule.rlist);
1426 list_replace_rcu(&entry->list, &nentry->list);
1427 list_replace(&r->list, &nentry->rule.list);
1429 call_rcu(&entry->rcu, audit_free_rule_rcu);
1434 /* This function will re-initialize the lsm_rule field of all applicable rules.
1435 * It will traverse the filter lists serarching for rules that contain LSM
1436 * specific filter fields. When such a rule is found, it is copied, the
1437 * LSM field is re-initialized, and the old rule is replaced with the
1439 int audit_update_lsm_rules(void)
1441 struct audit_krule *r, *n;
1444 /* audit_filter_mutex synchronizes the writers */
1445 mutex_lock(&audit_filter_mutex);
1447 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1448 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1449 int res = update_lsm_rule(r);
1454 mutex_unlock(&audit_filter_mutex);