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++)
313 /* check if a field is valid for a given list */
314 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
318 if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
319 entry->rule.listnr != AUDIT_FILTER_USER)
326 /* Translate struct audit_rule to kernel's rule respresentation.
327 * Exists for backward compatibility with userspace. */
328 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
330 struct audit_entry *entry;
334 entry = audit_to_entry_common(rule);
338 for (i = 0; i < rule->field_count; i++) {
339 struct audit_field *f = &entry->rule.fields[i];
342 n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
344 /* Support for legacy operators where
345 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
346 if (n & AUDIT_NEGATE)
347 f->op = Audit_not_equal;
351 f->op = audit_to_op(n);
353 entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1;
355 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
356 f->val = rule->values[i];
357 f->uid = INVALID_UID;
358 f->gid = INVALID_GID;
361 if (f->op == Audit_bad)
372 /* bit ops not implemented for uid comparisons */
373 if (f->op == Audit_bitmask || f->op == Audit_bittest)
376 f->uid = make_kuid(current_user_ns(), f->val);
377 if (!uid_valid(f->uid))
384 /* bit ops not implemented for gid comparisons */
385 if (f->op == Audit_bitmask || f->op == Audit_bittest)
388 f->gid = make_kgid(current_user_ns(), f->val);
389 if (!gid_valid(f->gid))
400 /* bit ops are only useful on syscall args */
401 if (f->op == Audit_bitmask || f->op == Audit_bittest)
409 /* arch is only allowed to be = or != */
411 if (f->op != Audit_not_equal && f->op != Audit_equal)
413 entry->rule.arch_f = f;
420 if (f->val & ~S_IFMT)
424 err = audit_to_inode(&entry->rule, f);
431 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
432 entry->rule.inode_f = NULL;
438 audit_free_rule(entry);
442 /* Translate struct audit_rule_data to kernel's rule respresentation. */
443 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
447 struct audit_entry *entry;
449 size_t remain = datasz - sizeof(struct audit_rule_data);
453 entry = audit_to_entry_common((struct audit_rule *)data);
458 entry->rule.vers_ops = 2;
459 for (i = 0; i < data->field_count; i++) {
460 struct audit_field *f = &entry->rule.fields[i];
464 f->op = audit_to_op(data->fieldflags[i]);
465 if (f->op == Audit_bad)
468 f->type = data->fields[i];
469 f->val = data->values[i];
470 f->uid = INVALID_UID;
471 f->gid = INVALID_GID;
475 err = audit_field_valid(entry, f);
488 /* bit ops not implemented for uid comparisons */
489 if (f->op == Audit_bitmask || f->op == Audit_bittest)
492 f->uid = make_kuid(current_user_ns(), f->val);
493 if (!uid_valid(f->uid))
501 /* bit ops not implemented for gid comparisons */
502 if (f->op == Audit_bitmask || f->op == Audit_bittest)
505 f->gid = make_kgid(current_user_ns(), f->val);
506 if (!gid_valid(f->gid))
523 entry->rule.arch_f = f;
525 case AUDIT_SUBJ_USER:
526 case AUDIT_SUBJ_ROLE:
527 case AUDIT_SUBJ_TYPE:
533 case AUDIT_OBJ_LEV_LOW:
534 case AUDIT_OBJ_LEV_HIGH:
535 str = audit_unpack_string(&bufp, &remain, f->val);
538 entry->rule.buflen += f->val;
540 err = security_audit_rule_init(f->type, f->op, str,
541 (void **)&f->lsm_rule);
542 /* Keep currently invalid fields around in case they
543 * become valid after a policy reload. */
544 if (err == -EINVAL) {
545 printk(KERN_WARNING "audit rule for LSM "
546 "\'%s\' is invalid\n", str);
556 str = audit_unpack_string(&bufp, &remain, f->val);
559 entry->rule.buflen += f->val;
561 err = audit_to_watch(&entry->rule, str, f->val, f->op);
568 str = audit_unpack_string(&bufp, &remain, f->val);
571 entry->rule.buflen += f->val;
573 err = audit_make_tree(&entry->rule, str, f->op);
579 err = audit_to_inode(&entry->rule, f);
583 case AUDIT_FILTERKEY:
584 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
586 str = audit_unpack_string(&bufp, &remain, f->val);
589 entry->rule.buflen += f->val;
590 entry->rule.filterkey = str;
597 if (f->val & ~S_IFMT)
600 case AUDIT_FIELD_COMPARE:
601 if (f->val > AUDIT_MAX_FIELD_COMPARE)
609 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
610 entry->rule.inode_f = NULL;
616 audit_free_rule(entry);
620 /* Pack a filter field's string representation into data block. */
621 static inline size_t audit_pack_string(void **bufp, const char *str)
623 size_t len = strlen(str);
625 memcpy(*bufp, str, len);
631 /* Translate kernel rule respresentation to struct audit_rule.
632 * Exists for backward compatibility with userspace. */
633 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
635 struct audit_rule *rule;
638 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
642 rule->flags = krule->flags | krule->listnr;
643 rule->action = krule->action;
644 rule->field_count = krule->field_count;
645 for (i = 0; i < rule->field_count; i++) {
646 rule->values[i] = krule->fields[i].val;
647 rule->fields[i] = krule->fields[i].type;
649 if (krule->vers_ops == 1) {
650 if (krule->fields[i].op == Audit_not_equal)
651 rule->fields[i] |= AUDIT_NEGATE;
653 rule->fields[i] |= audit_ops[krule->fields[i].op];
656 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
661 /* Translate kernel rule respresentation to struct audit_rule_data. */
662 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
664 struct audit_rule_data *data;
668 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
671 memset(data, 0, sizeof(*data));
673 data->flags = krule->flags | krule->listnr;
674 data->action = krule->action;
675 data->field_count = krule->field_count;
677 for (i = 0; i < data->field_count; i++) {
678 struct audit_field *f = &krule->fields[i];
680 data->fields[i] = f->type;
681 data->fieldflags[i] = audit_ops[f->op];
683 case AUDIT_SUBJ_USER:
684 case AUDIT_SUBJ_ROLE:
685 case AUDIT_SUBJ_TYPE:
691 case AUDIT_OBJ_LEV_LOW:
692 case AUDIT_OBJ_LEV_HIGH:
693 data->buflen += data->values[i] =
694 audit_pack_string(&bufp, f->lsm_str);
697 data->buflen += data->values[i] =
698 audit_pack_string(&bufp,
699 audit_watch_path(krule->watch));
702 data->buflen += data->values[i] =
703 audit_pack_string(&bufp,
704 audit_tree_path(krule->tree));
706 case AUDIT_FILTERKEY:
707 data->buflen += data->values[i] =
708 audit_pack_string(&bufp, krule->filterkey);
711 data->values[i] = f->val;
714 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
719 /* Compare two rules in kernel format. Considered success if rules
721 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
725 if (a->flags != b->flags ||
726 a->listnr != b->listnr ||
727 a->action != b->action ||
728 a->field_count != b->field_count)
731 for (i = 0; i < a->field_count; i++) {
732 if (a->fields[i].type != b->fields[i].type ||
733 a->fields[i].op != b->fields[i].op)
736 switch(a->fields[i].type) {
737 case AUDIT_SUBJ_USER:
738 case AUDIT_SUBJ_ROLE:
739 case AUDIT_SUBJ_TYPE:
745 case AUDIT_OBJ_LEV_LOW:
746 case AUDIT_OBJ_LEV_HIGH:
747 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
751 if (strcmp(audit_watch_path(a->watch),
752 audit_watch_path(b->watch)))
756 if (strcmp(audit_tree_path(a->tree),
757 audit_tree_path(b->tree)))
760 case AUDIT_FILTERKEY:
761 /* both filterkeys exist based on above type compare */
762 if (strcmp(a->filterkey, b->filterkey))
771 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
779 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
783 if (a->fields[i].val != b->fields[i].val)
788 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
789 if (a->mask[i] != b->mask[i])
795 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
797 static inline int audit_dupe_lsm_field(struct audit_field *df,
798 struct audit_field *sf)
803 /* our own copy of lsm_str */
804 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
805 if (unlikely(!lsm_str))
807 df->lsm_str = lsm_str;
809 /* our own (refreshed) copy of lsm_rule */
810 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
811 (void **)&df->lsm_rule);
812 /* Keep currently invalid fields around in case they
813 * become valid after a policy reload. */
814 if (ret == -EINVAL) {
815 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
816 "invalid\n", df->lsm_str);
823 /* Duplicate an audit rule. This will be a deep copy with the exception
824 * of the watch - that pointer is carried over. The LSM specific fields
825 * will be updated in the copy. The point is to be able to replace the old
826 * rule with the new rule in the filterlist, then free the old rule.
827 * The rlist element is undefined; list manipulations are handled apart from
828 * the initial copy. */
829 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
831 u32 fcount = old->field_count;
832 struct audit_entry *entry;
833 struct audit_krule *new;
837 entry = audit_init_entry(fcount);
838 if (unlikely(!entry))
839 return ERR_PTR(-ENOMEM);
842 new->vers_ops = old->vers_ops;
843 new->flags = old->flags;
844 new->listnr = old->listnr;
845 new->action = old->action;
846 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
847 new->mask[i] = old->mask[i];
848 new->prio = old->prio;
849 new->buflen = old->buflen;
850 new->inode_f = old->inode_f;
851 new->field_count = old->field_count;
854 * note that we are OK with not refcounting here; audit_match_tree()
855 * never dereferences tree and we can't get false positives there
856 * since we'd have to have rule gone from the list *and* removed
857 * before the chunks found by lookup had been allocated, i.e. before
858 * the beginning of list scan.
860 new->tree = old->tree;
861 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
863 /* deep copy this information, updating the lsm_rule fields, because
864 * the originals will all be freed when the old rule is freed. */
865 for (i = 0; i < fcount; i++) {
866 switch (new->fields[i].type) {
867 case AUDIT_SUBJ_USER:
868 case AUDIT_SUBJ_ROLE:
869 case AUDIT_SUBJ_TYPE:
875 case AUDIT_OBJ_LEV_LOW:
876 case AUDIT_OBJ_LEV_HIGH:
877 err = audit_dupe_lsm_field(&new->fields[i],
880 case AUDIT_FILTERKEY:
881 fk = kstrdup(old->filterkey, GFP_KERNEL);
888 audit_free_rule(entry);
894 audit_get_watch(old->watch);
895 new->watch = old->watch;
901 /* Find an existing audit rule.
902 * Caller must hold audit_filter_mutex to prevent stale rule data. */
903 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
904 struct list_head **p)
906 struct audit_entry *e, *found = NULL;
907 struct list_head *list;
910 if (entry->rule.inode_f) {
911 h = audit_hash_ino(entry->rule.inode_f->val);
912 *p = list = &audit_inode_hash[h];
913 } else if (entry->rule.watch) {
914 /* we don't know the inode number, so must walk entire hash */
915 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
916 list = &audit_inode_hash[h];
917 list_for_each_entry(e, list, list)
918 if (!audit_compare_rule(&entry->rule, &e->rule)) {
925 *p = list = &audit_filter_list[entry->rule.listnr];
928 list_for_each_entry(e, list, list)
929 if (!audit_compare_rule(&entry->rule, &e->rule)) {
938 static u64 prio_low = ~0ULL/2;
939 static u64 prio_high = ~0ULL/2 - 1;
941 /* Add rule to given filterlist if not a duplicate. */
942 static inline int audit_add_rule(struct audit_entry *entry)
944 struct audit_entry *e;
945 struct audit_watch *watch = entry->rule.watch;
946 struct audit_tree *tree = entry->rule.tree;
947 struct list_head *list;
949 #ifdef CONFIG_AUDITSYSCALL
952 /* If either of these, don't count towards total */
953 if (entry->rule.listnr == AUDIT_FILTER_USER ||
954 entry->rule.listnr == AUDIT_FILTER_TYPE)
958 mutex_lock(&audit_filter_mutex);
959 e = audit_find_rule(entry, &list);
961 mutex_unlock(&audit_filter_mutex);
963 /* normally audit_add_tree_rule() will free it on failure */
965 audit_put_tree(tree);
970 /* audit_filter_mutex is dropped and re-taken during this call */
971 err = audit_add_watch(&entry->rule, &list);
973 mutex_unlock(&audit_filter_mutex);
978 err = audit_add_tree_rule(&entry->rule);
980 mutex_unlock(&audit_filter_mutex);
985 entry->rule.prio = ~0ULL;
986 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
987 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
988 entry->rule.prio = ++prio_high;
990 entry->rule.prio = --prio_low;
993 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
994 list_add(&entry->rule.list,
995 &audit_rules_list[entry->rule.listnr]);
996 list_add_rcu(&entry->list, list);
997 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
999 list_add_tail(&entry->rule.list,
1000 &audit_rules_list[entry->rule.listnr]);
1001 list_add_tail_rcu(&entry->list, list);
1003 #ifdef CONFIG_AUDITSYSCALL
1007 if (!audit_match_signal(entry))
1010 mutex_unlock(&audit_filter_mutex);
1016 audit_put_watch(watch); /* tmp watch, matches initial get */
1020 /* Remove an existing rule from filterlist. */
1021 static inline int audit_del_rule(struct audit_entry *entry)
1023 struct audit_entry *e;
1024 struct audit_watch *watch = entry->rule.watch;
1025 struct audit_tree *tree = entry->rule.tree;
1026 struct list_head *list;
1028 #ifdef CONFIG_AUDITSYSCALL
1031 /* If either of these, don't count towards total */
1032 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1033 entry->rule.listnr == AUDIT_FILTER_TYPE)
1037 mutex_lock(&audit_filter_mutex);
1038 e = audit_find_rule(entry, &list);
1040 mutex_unlock(&audit_filter_mutex);
1046 audit_remove_watch_rule(&e->rule);
1049 audit_remove_tree_rule(&e->rule);
1051 list_del_rcu(&e->list);
1052 list_del(&e->rule.list);
1053 call_rcu(&e->rcu, audit_free_rule_rcu);
1055 #ifdef CONFIG_AUDITSYSCALL
1059 if (!audit_match_signal(entry))
1062 mutex_unlock(&audit_filter_mutex);
1066 audit_put_watch(watch); /* match initial get */
1068 audit_put_tree(tree); /* that's the temporary one */
1073 /* List rules using struct audit_rule. Exists for backward
1074 * compatibility with userspace. */
1075 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1077 struct sk_buff *skb;
1078 struct audit_krule *r;
1081 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1082 * iterator to sync with list writers. */
1083 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1084 list_for_each_entry(r, &audit_rules_list[i], list) {
1085 struct audit_rule *rule;
1087 rule = audit_krule_to_rule(r);
1088 if (unlikely(!rule))
1090 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1091 rule, sizeof(*rule));
1093 skb_queue_tail(q, skb);
1097 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1099 skb_queue_tail(q, skb);
1102 /* List rules using struct audit_rule_data. */
1103 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1105 struct sk_buff *skb;
1106 struct audit_krule *r;
1109 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1110 * iterator to sync with list writers. */
1111 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1112 list_for_each_entry(r, &audit_rules_list[i], list) {
1113 struct audit_rule_data *data;
1115 data = audit_krule_to_data(r);
1116 if (unlikely(!data))
1118 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1119 data, sizeof(*data) + data->buflen);
1121 skb_queue_tail(q, skb);
1125 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1127 skb_queue_tail(q, skb);
1130 /* Log rule additions and removals */
1131 static void audit_log_rule_change(kuid_t loginuid, u32 sessionid, u32 sid,
1132 char *action, struct audit_krule *rule,
1135 struct audit_buffer *ab;
1140 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1143 audit_log_format(ab, "auid=%u ses=%u",
1144 from_kuid(&init_user_ns, loginuid), sessionid);
1148 if (security_secid_to_secctx(sid, &ctx, &len))
1149 audit_log_format(ab, " ssid=%u", sid);
1151 audit_log_format(ab, " subj=%s", ctx);
1152 security_release_secctx(ctx, len);
1155 audit_log_format(ab, " op=");
1156 audit_log_string(ab, action);
1157 audit_log_key(ab, rule->filterkey);
1158 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1163 * audit_receive_filter - apply all rules to the specified message type
1164 * @type: audit message type
1165 * @pid: target pid for netlink audit messages
1166 * @seq: netlink audit message sequence (serial) number
1167 * @data: payload data
1168 * @datasz: size of payload data
1169 * @loginuid: loginuid of sender
1170 * @sessionid: sessionid for netlink audit message
1171 * @sid: SE Linux Security ID of sender
1173 int audit_receive_filter(int type, int pid, int seq, void *data,
1174 size_t datasz, kuid_t loginuid, u32 sessionid, u32 sid)
1176 struct task_struct *tsk;
1177 struct audit_netlink_list *dest;
1179 struct audit_entry *entry;
1183 case AUDIT_LIST_RULES:
1184 /* We can't just spew out the rules here because we might fill
1185 * the available socket buffer space and deadlock waiting for
1186 * auditctl to read from it... which isn't ever going to
1187 * happen if we're actually running in the context of auditctl
1188 * trying to _send_ the stuff */
1190 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1194 skb_queue_head_init(&dest->q);
1196 mutex_lock(&audit_filter_mutex);
1197 if (type == AUDIT_LIST)
1198 audit_list(pid, seq, &dest->q);
1200 audit_list_rules(pid, seq, &dest->q);
1201 mutex_unlock(&audit_filter_mutex);
1203 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1205 skb_queue_purge(&dest->q);
1211 case AUDIT_ADD_RULE:
1212 if (type == AUDIT_ADD)
1213 entry = audit_rule_to_entry(data);
1215 entry = audit_data_to_entry(data, datasz);
1217 return PTR_ERR(entry);
1219 err = audit_add_rule(entry);
1220 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1221 &entry->rule, !err);
1224 audit_free_rule(entry);
1227 case AUDIT_DEL_RULE:
1228 if (type == AUDIT_DEL)
1229 entry = audit_rule_to_entry(data);
1231 entry = audit_data_to_entry(data, datasz);
1233 return PTR_ERR(entry);
1235 err = audit_del_rule(entry);
1236 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1237 &entry->rule, !err);
1239 audit_free_rule(entry);
1248 int audit_comparator(u32 left, u32 op, u32 right)
1252 return (left == right);
1253 case Audit_not_equal:
1254 return (left != right);
1256 return (left < right);
1258 return (left <= right);
1260 return (left > right);
1262 return (left >= right);
1264 return (left & right);
1266 return ((left & right) == right);
1273 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1277 return uid_eq(left, right);
1278 case Audit_not_equal:
1279 return !uid_eq(left, right);
1281 return uid_lt(left, right);
1283 return uid_lte(left, right);
1285 return uid_gt(left, right);
1287 return uid_gte(left, right);
1296 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1300 return gid_eq(left, right);
1301 case Audit_not_equal:
1302 return !gid_eq(left, right);
1304 return gid_lt(left, right);
1306 return gid_lte(left, right);
1308 return gid_gt(left, right);
1310 return gid_gte(left, right);
1320 * parent_len - find the length of the parent portion of a pathname
1321 * @path: pathname of which to determine length
1323 int parent_len(const char *path)
1328 plen = strlen(path);
1333 /* disregard trailing slashes */
1334 p = path + plen - 1;
1335 while ((*p == '/') && (p > path))
1338 /* walk backward until we find the next slash or hit beginning */
1339 while ((*p != '/') && (p > path))
1342 /* did we find a slash? Then increment to include it in path */
1350 * audit_compare_dname_path - compare given dentry name with last component in
1351 * given path. Return of 0 indicates a match.
1352 * @dname: dentry name that we're comparing
1353 * @path: full pathname that we're comparing
1354 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1355 * here indicates that we must compute this value.
1357 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1362 dlen = strlen(dname);
1363 pathlen = strlen(path);
1367 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1368 if (pathlen - parentlen != dlen)
1371 p = path + parentlen;
1373 return strncmp(p, dname, dlen);
1376 static int audit_filter_user_rules(struct audit_krule *rule, int type,
1377 enum audit_state *state)
1381 for (i = 0; i < rule->field_count; i++) {
1382 struct audit_field *f = &rule->fields[i];
1388 result = audit_comparator(task_pid_vnr(current), f->op, f->val);
1391 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1394 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1396 case AUDIT_LOGINUID:
1397 result = audit_uid_comparator(audit_get_loginuid(current),
1401 result = audit_comparator(type, f->op, f->val);
1403 case AUDIT_SUBJ_USER:
1404 case AUDIT_SUBJ_ROLE:
1405 case AUDIT_SUBJ_TYPE:
1406 case AUDIT_SUBJ_SEN:
1407 case AUDIT_SUBJ_CLR:
1409 security_task_getsecid(current, &sid);
1410 result = security_audit_rule_match(sid,
1422 switch (rule->action) {
1423 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1424 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1429 int audit_filter_user(int type)
1431 enum audit_state state = AUDIT_DISABLED;
1432 struct audit_entry *e;
1436 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1437 if (audit_filter_user_rules(&e->rule, type, &state)) {
1438 if (state == AUDIT_DISABLED)
1445 return ret; /* Audit by default */
1448 int audit_filter_type(int type)
1450 struct audit_entry *e;
1454 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1455 goto unlock_and_return;
1457 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1460 for (i = 0; i < e->rule.field_count; i++) {
1461 struct audit_field *f = &e->rule.fields[i];
1462 if (f->type == AUDIT_MSGTYPE) {
1463 result = audit_comparator(type, f->op, f->val);
1469 goto unlock_and_return;
1476 static int update_lsm_rule(struct audit_krule *r)
1478 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1479 struct audit_entry *nentry;
1482 if (!security_audit_rule_known(r))
1485 nentry = audit_dupe_rule(r);
1486 if (IS_ERR(nentry)) {
1487 /* save the first error encountered for the
1489 err = PTR_ERR(nentry);
1490 audit_panic("error updating LSM filters");
1492 list_del(&r->rlist);
1493 list_del_rcu(&entry->list);
1496 if (r->watch || r->tree)
1497 list_replace_init(&r->rlist, &nentry->rule.rlist);
1498 list_replace_rcu(&entry->list, &nentry->list);
1499 list_replace(&r->list, &nentry->rule.list);
1501 call_rcu(&entry->rcu, audit_free_rule_rcu);
1506 /* This function will re-initialize the lsm_rule field of all applicable rules.
1507 * It will traverse the filter lists serarching for rules that contain LSM
1508 * specific filter fields. When such a rule is found, it is copied, the
1509 * LSM field is re-initialized, and the old rule is replaced with the
1511 int audit_update_lsm_rules(void)
1513 struct audit_krule *r, *n;
1516 /* audit_filter_mutex synchronizes the writers */
1517 mutex_lock(&audit_filter_mutex);
1519 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1520 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1521 int res = update_lsm_rule(r);
1526 mutex_unlock(&audit_filter_mutex);