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/inotify.h>
31 #include <linux/security.h>
32 #include <linux/selinux.h>
39 * Synchronizes writes and blocking reads of audit's filterlist
40 * data. Rcu is used to traverse the filterlist and access
41 * contents of structs audit_entry, audit_watch and opaque
42 * selinux rules during filtering. If modified, these structures
43 * must be copied and replace their counterparts in the filterlist.
44 * An audit_parent struct is not accessed during filtering, so may
45 * be written directly provided audit_filter_mutex is held.
51 * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
52 * event. Each audit_watch holds a reference to its associated parent.
54 * audit_watch: if added to lists, lifetime is from audit_init_watch() to
55 * audit_remove_watch(). Additionally, an audit_watch may exist
56 * temporarily to assist in searching existing filter data. Each
57 * audit_krule holds a reference to its associated watch.
61 struct list_head ilist; /* entry in inotify registration list */
62 struct list_head watches; /* associated watches */
63 struct inotify_watch wdata; /* inotify watch data */
64 unsigned flags; /* status flags */
68 * audit_parent status flags:
70 * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
71 * a filesystem event to ensure we're adding audit watches to a valid parent.
72 * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
73 * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
74 * we can receive while holding nameidata.
76 #define AUDIT_PARENT_INVALID 0x001
78 /* Audit filter lists, defined in <linux/audit.h> */
79 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
80 LIST_HEAD_INIT(audit_filter_list[0]),
81 LIST_HEAD_INIT(audit_filter_list[1]),
82 LIST_HEAD_INIT(audit_filter_list[2]),
83 LIST_HEAD_INIT(audit_filter_list[3]),
84 LIST_HEAD_INIT(audit_filter_list[4]),
85 LIST_HEAD_INIT(audit_filter_list[5]),
86 #if AUDIT_NR_FILTERS != 6
87 #error Fix audit_filter_list initialiser
91 DEFINE_MUTEX(audit_filter_mutex);
94 extern struct inotify_handle *audit_ih;
96 /* Inotify events we care about. */
97 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
99 extern int audit_enabled;
101 void audit_free_parent(struct inotify_watch *i_watch)
103 struct audit_parent *parent;
105 parent = container_of(i_watch, struct audit_parent, wdata);
106 WARN_ON(!list_empty(&parent->watches));
110 static inline void audit_get_watch(struct audit_watch *watch)
112 atomic_inc(&watch->count);
115 static void audit_put_watch(struct audit_watch *watch)
117 if (atomic_dec_and_test(&watch->count)) {
118 WARN_ON(watch->parent);
119 WARN_ON(!list_empty(&watch->rules));
125 static void audit_remove_watch(struct audit_watch *watch)
127 list_del(&watch->wlist);
128 put_inotify_watch(&watch->parent->wdata);
129 watch->parent = NULL;
130 audit_put_watch(watch); /* match initial get */
133 static inline void audit_free_rule(struct audit_entry *e)
137 /* some rules don't have associated watches */
139 audit_put_watch(e->rule.watch);
141 for (i = 0; i < e->rule.field_count; i++) {
142 struct audit_field *f = &e->rule.fields[i];
144 selinux_audit_rule_free(f->se_rule);
146 kfree(e->rule.fields);
147 kfree(e->rule.filterkey);
151 void audit_free_rule_rcu(struct rcu_head *head)
153 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
157 /* Initialize a parent watch entry. */
158 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
160 struct audit_parent *parent;
163 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
164 if (unlikely(!parent))
165 return ERR_PTR(-ENOMEM);
167 INIT_LIST_HEAD(&parent->watches);
170 inotify_init_watch(&parent->wdata);
171 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
172 get_inotify_watch(&parent->wdata);
173 wd = inotify_add_watch(audit_ih, &parent->wdata,
174 ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
176 audit_free_parent(&parent->wdata);
183 /* Initialize a watch entry. */
184 static struct audit_watch *audit_init_watch(char *path)
186 struct audit_watch *watch;
188 watch = kzalloc(sizeof(*watch), GFP_KERNEL);
189 if (unlikely(!watch))
190 return ERR_PTR(-ENOMEM);
192 INIT_LIST_HEAD(&watch->rules);
193 atomic_set(&watch->count, 1);
195 watch->dev = (dev_t)-1;
196 watch->ino = (unsigned long)-1;
201 /* Initialize an audit filterlist entry. */
202 static inline struct audit_entry *audit_init_entry(u32 field_count)
204 struct audit_entry *entry;
205 struct audit_field *fields;
207 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
208 if (unlikely(!entry))
211 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
212 if (unlikely(!fields)) {
216 entry->rule.fields = fields;
221 /* Unpack a filter field's string representation from user-space
223 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
227 if (!*bufp || (len == 0) || (len > *remain))
228 return ERR_PTR(-EINVAL);
230 /* Of the currently implemented string fields, PATH_MAX
231 * defines the longest valid length.
234 return ERR_PTR(-ENAMETOOLONG);
236 str = kmalloc(len + 1, GFP_KERNEL);
238 return ERR_PTR(-ENOMEM);
240 memcpy(str, *bufp, len);
248 /* Translate an inode field to kernel respresentation. */
249 static inline int audit_to_inode(struct audit_krule *krule,
250 struct audit_field *f)
252 if (krule->listnr != AUDIT_FILTER_EXIT ||
253 krule->watch || krule->inode_f || krule->tree)
260 /* Translate a watch string to kernel respresentation. */
261 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
264 struct audit_watch *watch;
269 if (path[0] != '/' || path[len-1] == '/' ||
270 krule->listnr != AUDIT_FILTER_EXIT ||
272 krule->inode_f || krule->watch || krule->tree)
275 watch = audit_init_watch(path);
276 if (unlikely(IS_ERR(watch)))
277 return PTR_ERR(watch);
279 audit_get_watch(watch);
280 krule->watch = watch;
285 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
287 int __init audit_register_class(int class, unsigned *list)
289 __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
292 while (*list != ~0U) {
293 unsigned n = *list++;
294 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
298 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
300 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
308 int audit_match_class(int class, unsigned syscall)
310 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
312 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
314 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
317 #ifdef CONFIG_AUDITSYSCALL
318 static inline int audit_match_class_bits(int class, u32 *mask)
322 if (classes[class]) {
323 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
324 if (mask[i] & classes[class][i])
330 static int audit_match_signal(struct audit_entry *entry)
332 struct audit_field *arch = entry->rule.arch_f;
335 /* When arch is unspecified, we must check both masks on biarch
336 * as syscall number alone is ambiguous. */
337 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
339 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
343 switch(audit_classify_arch(arch->val)) {
345 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
347 case 1: /* 32bit on biarch */
348 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
356 /* Common user-space to kernel rule translation. */
357 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
360 struct audit_entry *entry;
364 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
368 case AUDIT_FILTER_USER:
369 case AUDIT_FILTER_TYPE:
370 #ifdef CONFIG_AUDITSYSCALL
371 case AUDIT_FILTER_ENTRY:
372 case AUDIT_FILTER_EXIT:
373 case AUDIT_FILTER_TASK:
377 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
378 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
381 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
383 if (rule->field_count > AUDIT_MAX_FIELDS)
387 entry = audit_init_entry(rule->field_count);
391 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
392 entry->rule.listnr = listnr;
393 entry->rule.action = rule->action;
394 entry->rule.field_count = rule->field_count;
396 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
397 entry->rule.mask[i] = rule->mask[i];
399 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
400 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
401 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
404 if (!(*p & AUDIT_BIT(bit)))
406 *p &= ~AUDIT_BIT(bit);
410 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
411 entry->rule.mask[j] |= class[j];
421 /* Translate struct audit_rule to kernel's rule respresentation.
422 * Exists for backward compatibility with userspace. */
423 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
425 struct audit_entry *entry;
426 struct audit_field *f;
430 entry = audit_to_entry_common(rule);
434 for (i = 0; i < rule->field_count; i++) {
435 struct audit_field *f = &entry->rule.fields[i];
437 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
438 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
439 f->val = rule->values[i];
462 /* bit ops are only useful on syscall args */
463 if (f->op == AUDIT_BIT_MASK ||
464 f->op == AUDIT_BIT_TEST) {
474 /* arch is only allowed to be = or != */
476 if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL)
477 && (f->op != AUDIT_NEGATE) && (f->op)) {
481 entry->rule.arch_f = f;
488 err = audit_to_inode(&entry->rule, f);
494 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
496 /* Support for legacy operators where
497 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
498 if (f->op & AUDIT_NEGATE)
499 f->op = AUDIT_NOT_EQUAL;
502 else if (f->op == AUDIT_OPERATORS) {
508 f = entry->rule.inode_f;
511 case AUDIT_NOT_EQUAL:
512 entry->rule.inode_f = NULL;
525 audit_free_rule(entry);
529 /* Translate struct audit_rule_data to kernel's rule respresentation. */
530 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
534 struct audit_entry *entry;
535 struct audit_field *f;
537 size_t remain = datasz - sizeof(struct audit_rule_data);
541 entry = audit_to_entry_common((struct audit_rule *)data);
546 entry->rule.vers_ops = 2;
547 for (i = 0; i < data->field_count; i++) {
548 struct audit_field *f = &entry->rule.fields[i];
551 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
552 data->fieldflags[i] & ~AUDIT_OPERATORS)
555 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
556 f->type = data->fields[i];
557 f->val = data->values[i];
584 entry->rule.arch_f = f;
586 case AUDIT_SUBJ_USER:
587 case AUDIT_SUBJ_ROLE:
588 case AUDIT_SUBJ_TYPE:
594 case AUDIT_OBJ_LEV_LOW:
595 case AUDIT_OBJ_LEV_HIGH:
596 str = audit_unpack_string(&bufp, &remain, f->val);
599 entry->rule.buflen += f->val;
601 err = selinux_audit_rule_init(f->type, f->op, str,
603 /* Keep currently invalid fields around in case they
604 * become valid after a policy reload. */
605 if (err == -EINVAL) {
606 printk(KERN_WARNING "audit rule for selinux "
607 "\'%s\' is invalid\n", str);
617 str = audit_unpack_string(&bufp, &remain, f->val);
620 entry->rule.buflen += f->val;
622 err = audit_to_watch(&entry->rule, str, f->val, f->op);
629 str = audit_unpack_string(&bufp, &remain, f->val);
632 entry->rule.buflen += f->val;
634 err = audit_make_tree(&entry->rule, str, f->op);
640 err = audit_to_inode(&entry->rule, f);
644 case AUDIT_FILTERKEY:
646 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
648 str = audit_unpack_string(&bufp, &remain, f->val);
651 entry->rule.buflen += f->val;
652 entry->rule.filterkey = str;
663 f = entry->rule.inode_f;
666 case AUDIT_NOT_EQUAL:
667 entry->rule.inode_f = NULL;
680 audit_free_rule(entry);
684 /* Pack a filter field's string representation into data block. */
685 static inline size_t audit_pack_string(void **bufp, const char *str)
687 size_t len = strlen(str);
689 memcpy(*bufp, str, len);
695 /* Translate kernel rule respresentation to struct audit_rule.
696 * Exists for backward compatibility with userspace. */
697 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
699 struct audit_rule *rule;
702 rule = kzalloc(sizeof(*rule), GFP_KERNEL);
706 rule->flags = krule->flags | krule->listnr;
707 rule->action = krule->action;
708 rule->field_count = krule->field_count;
709 for (i = 0; i < rule->field_count; i++) {
710 rule->values[i] = krule->fields[i].val;
711 rule->fields[i] = krule->fields[i].type;
713 if (krule->vers_ops == 1) {
714 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
715 rule->fields[i] |= AUDIT_NEGATE;
717 rule->fields[i] |= krule->fields[i].op;
720 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
725 /* Translate kernel rule respresentation to struct audit_rule_data. */
726 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
728 struct audit_rule_data *data;
732 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
735 memset(data, 0, sizeof(*data));
737 data->flags = krule->flags | krule->listnr;
738 data->action = krule->action;
739 data->field_count = krule->field_count;
741 for (i = 0; i < data->field_count; i++) {
742 struct audit_field *f = &krule->fields[i];
744 data->fields[i] = f->type;
745 data->fieldflags[i] = f->op;
747 case AUDIT_SUBJ_USER:
748 case AUDIT_SUBJ_ROLE:
749 case AUDIT_SUBJ_TYPE:
755 case AUDIT_OBJ_LEV_LOW:
756 case AUDIT_OBJ_LEV_HIGH:
757 data->buflen += data->values[i] =
758 audit_pack_string(&bufp, f->se_str);
761 data->buflen += data->values[i] =
762 audit_pack_string(&bufp, krule->watch->path);
765 data->buflen += data->values[i] =
766 audit_pack_string(&bufp,
767 audit_tree_path(krule->tree));
769 case AUDIT_FILTERKEY:
770 data->buflen += data->values[i] =
771 audit_pack_string(&bufp, krule->filterkey);
774 data->values[i] = f->val;
777 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
782 /* Compare two rules in kernel format. Considered success if rules
784 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
788 if (a->flags != b->flags ||
789 a->listnr != b->listnr ||
790 a->action != b->action ||
791 a->field_count != b->field_count)
794 for (i = 0; i < a->field_count; i++) {
795 if (a->fields[i].type != b->fields[i].type ||
796 a->fields[i].op != b->fields[i].op)
799 switch(a->fields[i].type) {
800 case AUDIT_SUBJ_USER:
801 case AUDIT_SUBJ_ROLE:
802 case AUDIT_SUBJ_TYPE:
808 case AUDIT_OBJ_LEV_LOW:
809 case AUDIT_OBJ_LEV_HIGH:
810 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
814 if (strcmp(a->watch->path, b->watch->path))
818 if (strcmp(audit_tree_path(a->tree),
819 audit_tree_path(b->tree)))
822 case AUDIT_FILTERKEY:
823 /* both filterkeys exist based on above type compare */
824 if (strcmp(a->filterkey, b->filterkey))
828 if (a->fields[i].val != b->fields[i].val)
833 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
834 if (a->mask[i] != b->mask[i])
840 /* Duplicate the given audit watch. The new watch's rules list is initialized
841 * to an empty list and wlist is undefined. */
842 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
845 struct audit_watch *new;
847 path = kstrdup(old->path, GFP_KERNEL);
849 return ERR_PTR(-ENOMEM);
851 new = audit_init_watch(path);
852 if (unlikely(IS_ERR(new))) {
859 get_inotify_watch(&old->parent->wdata);
860 new->parent = old->parent;
866 /* Duplicate selinux field information. The se_rule is opaque, so must be
868 static inline int audit_dupe_selinux_field(struct audit_field *df,
869 struct audit_field *sf)
874 /* our own copy of se_str */
875 se_str = kstrdup(sf->se_str, GFP_KERNEL);
876 if (unlikely(!se_str))
880 /* our own (refreshed) copy of se_rule */
881 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
883 /* Keep currently invalid fields around in case they
884 * become valid after a policy reload. */
885 if (ret == -EINVAL) {
886 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
887 "invalid\n", df->se_str);
894 /* Duplicate an audit rule. This will be a deep copy with the exception
895 * of the watch - that pointer is carried over. The selinux specific fields
896 * will be updated in the copy. The point is to be able to replace the old
897 * rule with the new rule in the filterlist, then free the old rule.
898 * The rlist element is undefined; list manipulations are handled apart from
899 * the initial copy. */
900 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
901 struct audit_watch *watch)
903 u32 fcount = old->field_count;
904 struct audit_entry *entry;
905 struct audit_krule *new;
909 entry = audit_init_entry(fcount);
910 if (unlikely(!entry))
911 return ERR_PTR(-ENOMEM);
914 new->vers_ops = old->vers_ops;
915 new->flags = old->flags;
916 new->listnr = old->listnr;
917 new->action = old->action;
918 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
919 new->mask[i] = old->mask[i];
920 new->buflen = old->buflen;
921 new->inode_f = old->inode_f;
923 new->field_count = old->field_count;
925 * note that we are OK with not refcounting here; audit_match_tree()
926 * never dereferences tree and we can't get false positives there
927 * since we'd have to have rule gone from the list *and* removed
928 * before the chunks found by lookup had been allocated, i.e. before
929 * the beginning of list scan.
931 new->tree = old->tree;
932 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
934 /* deep copy this information, updating the se_rule fields, because
935 * the originals will all be freed when the old rule is freed. */
936 for (i = 0; i < fcount; i++) {
937 switch (new->fields[i].type) {
938 case AUDIT_SUBJ_USER:
939 case AUDIT_SUBJ_ROLE:
940 case AUDIT_SUBJ_TYPE:
946 case AUDIT_OBJ_LEV_LOW:
947 case AUDIT_OBJ_LEV_HIGH:
948 err = audit_dupe_selinux_field(&new->fields[i],
951 case AUDIT_FILTERKEY:
952 fk = kstrdup(old->filterkey, GFP_KERNEL);
959 audit_free_rule(entry);
965 audit_get_watch(watch);
972 /* Update inode info in audit rules based on filesystem event. */
973 static void audit_update_watch(struct audit_parent *parent,
974 const char *dname, dev_t dev,
975 unsigned long ino, unsigned invalidating)
977 struct audit_watch *owatch, *nwatch, *nextw;
978 struct audit_krule *r, *nextr;
979 struct audit_entry *oentry, *nentry;
981 mutex_lock(&audit_filter_mutex);
982 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
983 if (audit_compare_dname_path(dname, owatch->path, NULL))
986 /* If the update involves invalidating rules, do the inode-based
987 * filtering now, so we don't omit records. */
988 if (invalidating && current->audit_context &&
989 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
990 audit_set_auditable(current->audit_context);
992 nwatch = audit_dupe_watch(owatch);
993 if (unlikely(IS_ERR(nwatch))) {
994 mutex_unlock(&audit_filter_mutex);
995 audit_panic("error updating watch, skipping");
1001 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
1003 oentry = container_of(r, struct audit_entry, rule);
1004 list_del(&oentry->rule.rlist);
1005 list_del_rcu(&oentry->list);
1007 nentry = audit_dupe_rule(&oentry->rule, nwatch);
1008 if (unlikely(IS_ERR(nentry)))
1009 audit_panic("error updating watch, removing");
1011 int h = audit_hash_ino((u32)ino);
1012 list_add(&nentry->rule.rlist, &nwatch->rules);
1013 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
1016 call_rcu(&oentry->rcu, audit_free_rule_rcu);
1019 if (audit_enabled) {
1020 struct audit_buffer *ab;
1021 ab = audit_log_start(NULL, GFP_KERNEL,
1022 AUDIT_CONFIG_CHANGE);
1023 audit_log_format(ab,
1024 "op=updated rules specifying path=");
1025 audit_log_untrustedstring(ab, owatch->path);
1026 audit_log_format(ab, " with dev=%u ino=%lu\n",
1028 audit_log_format(ab, " list=%d res=1", r->listnr);
1031 audit_remove_watch(owatch);
1032 goto add_watch_to_parent; /* event applies to a single watch */
1034 mutex_unlock(&audit_filter_mutex);
1037 add_watch_to_parent:
1038 list_add(&nwatch->wlist, &parent->watches);
1039 mutex_unlock(&audit_filter_mutex);
1043 /* Remove all watches & rules associated with a parent that is going away. */
1044 static void audit_remove_parent_watches(struct audit_parent *parent)
1046 struct audit_watch *w, *nextw;
1047 struct audit_krule *r, *nextr;
1048 struct audit_entry *e;
1050 mutex_lock(&audit_filter_mutex);
1051 parent->flags |= AUDIT_PARENT_INVALID;
1052 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
1053 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
1054 e = container_of(r, struct audit_entry, rule);
1055 if (audit_enabled) {
1056 struct audit_buffer *ab;
1057 ab = audit_log_start(NULL, GFP_KERNEL,
1058 AUDIT_CONFIG_CHANGE);
1059 audit_log_format(ab, "op=remove rule path=");
1060 audit_log_untrustedstring(ab, w->path);
1062 audit_log_format(ab, " key=");
1063 audit_log_untrustedstring(ab,
1066 audit_log_format(ab, " key=(null)");
1067 audit_log_format(ab, " list=%d res=1",
1071 list_del(&r->rlist);
1072 list_del_rcu(&e->list);
1073 call_rcu(&e->rcu, audit_free_rule_rcu);
1075 audit_remove_watch(w);
1077 mutex_unlock(&audit_filter_mutex);
1080 /* Unregister inotify watches for parents on in_list.
1081 * Generates an IN_IGNORED event. */
1082 static void audit_inotify_unregister(struct list_head *in_list)
1084 struct audit_parent *p, *n;
1086 list_for_each_entry_safe(p, n, in_list, ilist) {
1087 list_del(&p->ilist);
1088 inotify_rm_watch(audit_ih, &p->wdata);
1089 /* the put matching the get in audit_do_del_rule() */
1090 put_inotify_watch(&p->wdata);
1094 /* Find an existing audit rule.
1095 * Caller must hold audit_filter_mutex to prevent stale rule data. */
1096 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
1097 struct list_head *list)
1099 struct audit_entry *e, *found = NULL;
1102 if (entry->rule.watch) {
1103 /* we don't know the inode number, so must walk entire hash */
1104 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
1105 list = &audit_inode_hash[h];
1106 list_for_each_entry(e, list, list)
1107 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1115 list_for_each_entry(e, list, list)
1116 if (!audit_compare_rule(&entry->rule, &e->rule)) {
1125 /* Get path information necessary for adding watches. */
1126 static int audit_get_nd(char *path, struct nameidata **ndp,
1127 struct nameidata **ndw)
1129 struct nameidata *ndparent, *ndwatch;
1132 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
1133 if (unlikely(!ndparent))
1136 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
1137 if (unlikely(!ndwatch)) {
1142 err = path_lookup(path, LOOKUP_PARENT, ndparent);
1149 err = path_lookup(path, 0, ndwatch);
1161 /* Release resources used for watch path information. */
1162 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1165 path_put(&ndp->path);
1169 path_put(&ndw->path);
1174 /* Associate the given rule with an existing parent inotify_watch.
1175 * Caller must hold audit_filter_mutex. */
1176 static void audit_add_to_parent(struct audit_krule *krule,
1177 struct audit_parent *parent)
1179 struct audit_watch *w, *watch = krule->watch;
1180 int watch_found = 0;
1182 list_for_each_entry(w, &parent->watches, wlist) {
1183 if (strcmp(watch->path, w->path))
1188 /* put krule's and initial refs to temporary watch */
1189 audit_put_watch(watch);
1190 audit_put_watch(watch);
1193 krule->watch = watch = w;
1198 get_inotify_watch(&parent->wdata);
1199 watch->parent = parent;
1201 list_add(&watch->wlist, &parent->watches);
1203 list_add(&krule->rlist, &watch->rules);
1206 /* Find a matching watch entry, or add this one.
1207 * Caller must hold audit_filter_mutex. */
1208 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1209 struct nameidata *ndw)
1211 struct audit_watch *watch = krule->watch;
1212 struct inotify_watch *i_watch;
1213 struct audit_parent *parent;
1216 /* update watch filter fields */
1218 watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
1219 watch->ino = ndw->path.dentry->d_inode->i_ino;
1222 /* The audit_filter_mutex must not be held during inotify calls because
1223 * we hold it during inotify event callback processing. If an existing
1224 * inotify watch is found, inotify_find_watch() grabs a reference before
1227 mutex_unlock(&audit_filter_mutex);
1229 if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
1231 parent = audit_init_parent(ndp);
1232 if (IS_ERR(parent)) {
1233 /* caller expects mutex locked */
1234 mutex_lock(&audit_filter_mutex);
1235 return PTR_ERR(parent);
1238 parent = container_of(i_watch, struct audit_parent, wdata);
1240 mutex_lock(&audit_filter_mutex);
1242 /* parent was moved before we took audit_filter_mutex */
1243 if (parent->flags & AUDIT_PARENT_INVALID)
1246 audit_add_to_parent(krule, parent);
1248 /* match get in audit_init_parent or inotify_find_watch */
1249 put_inotify_watch(&parent->wdata);
1253 /* Add rule to given filterlist if not a duplicate. */
1254 static inline int audit_add_rule(struct audit_entry *entry,
1255 struct list_head *list)
1257 struct audit_entry *e;
1258 struct audit_field *inode_f = entry->rule.inode_f;
1259 struct audit_watch *watch = entry->rule.watch;
1260 struct audit_tree *tree = entry->rule.tree;
1261 struct nameidata *ndp = NULL, *ndw = NULL;
1263 #ifdef CONFIG_AUDITSYSCALL
1266 /* If either of these, don't count towards total */
1267 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1268 entry->rule.listnr == AUDIT_FILTER_TYPE)
1273 h = audit_hash_ino(inode_f->val);
1274 list = &audit_inode_hash[h];
1277 mutex_lock(&audit_filter_mutex);
1278 e = audit_find_rule(entry, list);
1279 mutex_unlock(&audit_filter_mutex);
1282 /* normally audit_add_tree_rule() will free it on failure */
1284 audit_put_tree(tree);
1288 /* Avoid calling path_lookup under audit_filter_mutex. */
1290 err = audit_get_nd(watch->path, &ndp, &ndw);
1295 mutex_lock(&audit_filter_mutex);
1297 /* audit_filter_mutex is dropped and re-taken during this call */
1298 err = audit_add_watch(&entry->rule, ndp, ndw);
1300 mutex_unlock(&audit_filter_mutex);
1303 h = audit_hash_ino((u32)watch->ino);
1304 list = &audit_inode_hash[h];
1307 err = audit_add_tree_rule(&entry->rule);
1309 mutex_unlock(&audit_filter_mutex);
1314 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1315 list_add_rcu(&entry->list, list);
1316 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1318 list_add_tail_rcu(&entry->list, list);
1320 #ifdef CONFIG_AUDITSYSCALL
1324 if (!audit_match_signal(entry))
1327 mutex_unlock(&audit_filter_mutex);
1329 audit_put_nd(ndp, ndw); /* NULL args OK */
1333 audit_put_nd(ndp, ndw); /* NULL args OK */
1335 audit_put_watch(watch); /* tmp watch, matches initial get */
1339 /* Remove an existing rule from filterlist. */
1340 static inline int audit_del_rule(struct audit_entry *entry,
1341 struct list_head *list)
1343 struct audit_entry *e;
1344 struct audit_field *inode_f = entry->rule.inode_f;
1345 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1346 struct audit_tree *tree = entry->rule.tree;
1347 LIST_HEAD(inotify_list);
1349 #ifdef CONFIG_AUDITSYSCALL
1352 /* If either of these, don't count towards total */
1353 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1354 entry->rule.listnr == AUDIT_FILTER_TYPE)
1359 h = audit_hash_ino(inode_f->val);
1360 list = &audit_inode_hash[h];
1363 mutex_lock(&audit_filter_mutex);
1364 e = audit_find_rule(entry, list);
1366 mutex_unlock(&audit_filter_mutex);
1371 watch = e->rule.watch;
1373 struct audit_parent *parent = watch->parent;
1375 list_del(&e->rule.rlist);
1377 if (list_empty(&watch->rules)) {
1378 audit_remove_watch(watch);
1380 if (list_empty(&parent->watches)) {
1381 /* Put parent on the inotify un-registration
1382 * list. Grab a reference before releasing
1383 * audit_filter_mutex, to be released in
1384 * audit_inotify_unregister(). */
1385 list_add(&parent->ilist, &inotify_list);
1386 get_inotify_watch(&parent->wdata);
1392 audit_remove_tree_rule(&e->rule);
1394 list_del_rcu(&e->list);
1395 call_rcu(&e->rcu, audit_free_rule_rcu);
1397 #ifdef CONFIG_AUDITSYSCALL
1401 if (!audit_match_signal(entry))
1404 mutex_unlock(&audit_filter_mutex);
1406 if (!list_empty(&inotify_list))
1407 audit_inotify_unregister(&inotify_list);
1411 audit_put_watch(tmp_watch); /* match initial get */
1413 audit_put_tree(tree); /* that's the temporary one */
1418 /* List rules using struct audit_rule. Exists for backward
1419 * compatibility with userspace. */
1420 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1422 struct sk_buff *skb;
1423 struct audit_entry *entry;
1426 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1427 * iterator to sync with list writers. */
1428 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1429 list_for_each_entry(entry, &audit_filter_list[i], list) {
1430 struct audit_rule *rule;
1432 rule = audit_krule_to_rule(&entry->rule);
1433 if (unlikely(!rule))
1435 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1436 rule, sizeof(*rule));
1438 skb_queue_tail(q, skb);
1442 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1443 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1444 struct audit_rule *rule;
1446 rule = audit_krule_to_rule(&entry->rule);
1447 if (unlikely(!rule))
1449 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1450 rule, sizeof(*rule));
1452 skb_queue_tail(q, skb);
1456 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1458 skb_queue_tail(q, skb);
1461 /* List rules using struct audit_rule_data. */
1462 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1464 struct sk_buff *skb;
1465 struct audit_entry *e;
1468 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1469 * iterator to sync with list writers. */
1470 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1471 list_for_each_entry(e, &audit_filter_list[i], list) {
1472 struct audit_rule_data *data;
1474 data = audit_krule_to_data(&e->rule);
1475 if (unlikely(!data))
1477 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1478 data, sizeof(*data) + data->buflen);
1480 skb_queue_tail(q, skb);
1484 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1485 list_for_each_entry(e, &audit_inode_hash[i], list) {
1486 struct audit_rule_data *data;
1488 data = audit_krule_to_data(&e->rule);
1489 if (unlikely(!data))
1491 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1492 data, sizeof(*data) + data->buflen);
1494 skb_queue_tail(q, skb);
1498 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1500 skb_queue_tail(q, skb);
1503 /* Log rule additions and removals */
1504 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1505 struct audit_krule *rule, int res)
1507 struct audit_buffer *ab;
1512 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1515 audit_log_format(ab, "auid=%u", loginuid);
1519 if (security_secid_to_secctx(sid, &ctx, &len))
1520 audit_log_format(ab, " ssid=%u", sid);
1522 audit_log_format(ab, " subj=%s", ctx);
1523 security_release_secctx(ctx, len);
1526 audit_log_format(ab, " op=%s rule key=", action);
1527 if (rule->filterkey)
1528 audit_log_untrustedstring(ab, rule->filterkey);
1530 audit_log_format(ab, "(null)");
1531 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1536 * audit_receive_filter - apply all rules to the specified message type
1537 * @type: audit message type
1538 * @pid: target pid for netlink audit messages
1539 * @uid: target uid for netlink audit messages
1540 * @seq: netlink audit message sequence (serial) number
1541 * @data: payload data
1542 * @datasz: size of payload data
1543 * @loginuid: loginuid of sender
1544 * @sid: SE Linux Security ID of sender
1546 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1547 size_t datasz, uid_t loginuid, u32 sid)
1549 struct task_struct *tsk;
1550 struct audit_netlink_list *dest;
1552 struct audit_entry *entry;
1556 case AUDIT_LIST_RULES:
1557 /* We can't just spew out the rules here because we might fill
1558 * the available socket buffer space and deadlock waiting for
1559 * auditctl to read from it... which isn't ever going to
1560 * happen if we're actually running in the context of auditctl
1561 * trying to _send_ the stuff */
1563 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1567 skb_queue_head_init(&dest->q);
1569 mutex_lock(&audit_filter_mutex);
1570 if (type == AUDIT_LIST)
1571 audit_list(pid, seq, &dest->q);
1573 audit_list_rules(pid, seq, &dest->q);
1574 mutex_unlock(&audit_filter_mutex);
1576 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1578 skb_queue_purge(&dest->q);
1584 case AUDIT_ADD_RULE:
1585 if (type == AUDIT_ADD)
1586 entry = audit_rule_to_entry(data);
1588 entry = audit_data_to_entry(data, datasz);
1590 return PTR_ERR(entry);
1592 err = audit_add_rule(entry,
1593 &audit_filter_list[entry->rule.listnr]);
1594 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1597 audit_free_rule(entry);
1600 case AUDIT_DEL_RULE:
1601 if (type == AUDIT_DEL)
1602 entry = audit_rule_to_entry(data);
1604 entry = audit_data_to_entry(data, datasz);
1606 return PTR_ERR(entry);
1608 err = audit_del_rule(entry,
1609 &audit_filter_list[entry->rule.listnr]);
1610 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1613 audit_free_rule(entry);
1622 int audit_comparator(const u32 left, const u32 op, const u32 right)
1626 return (left == right);
1627 case AUDIT_NOT_EQUAL:
1628 return (left != right);
1629 case AUDIT_LESS_THAN:
1630 return (left < right);
1631 case AUDIT_LESS_THAN_OR_EQUAL:
1632 return (left <= right);
1633 case AUDIT_GREATER_THAN:
1634 return (left > right);
1635 case AUDIT_GREATER_THAN_OR_EQUAL:
1636 return (left >= right);
1637 case AUDIT_BIT_MASK:
1638 return (left & right);
1639 case AUDIT_BIT_TEST:
1640 return ((left & right) == right);
1646 /* Compare given dentry name with last component in given path,
1647 * return of 0 indicates a match. */
1648 int audit_compare_dname_path(const char *dname, const char *path,
1654 if (!dname || !path)
1657 dlen = strlen(dname);
1658 plen = strlen(path);
1662 /* disregard trailing slashes */
1663 p = path + plen - 1;
1664 while ((*p == '/') && (p > path))
1667 /* find last path component */
1671 else if (p > path) {
1678 /* return length of path's directory component */
1681 return strncmp(p, dname, dlen);
1684 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1685 struct audit_krule *rule,
1686 enum audit_state *state)
1690 for (i = 0; i < rule->field_count; i++) {
1691 struct audit_field *f = &rule->fields[i];
1696 result = audit_comparator(cb->creds.pid, f->op, f->val);
1699 result = audit_comparator(cb->creds.uid, f->op, f->val);
1702 result = audit_comparator(cb->creds.gid, f->op, f->val);
1704 case AUDIT_LOGINUID:
1705 result = audit_comparator(cb->loginuid, f->op, f->val);
1712 switch (rule->action) {
1713 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1714 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1719 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1721 enum audit_state state = AUDIT_DISABLED;
1722 struct audit_entry *e;
1726 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1727 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1728 if (state == AUDIT_DISABLED)
1735 return ret; /* Audit by default */
1738 int audit_filter_type(int type)
1740 struct audit_entry *e;
1744 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1745 goto unlock_and_return;
1747 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1750 for (i = 0; i < e->rule.field_count; i++) {
1751 struct audit_field *f = &e->rule.fields[i];
1752 if (f->type == AUDIT_MSGTYPE) {
1753 result = audit_comparator(type, f->op, f->val);
1759 goto unlock_and_return;
1766 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1767 are selinux fields specified in the rule, 0 otherwise. */
1768 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1772 for (i = 0; i < rule->field_count; i++) {
1773 struct audit_field *f = &rule->fields[i];
1775 case AUDIT_SUBJ_USER:
1776 case AUDIT_SUBJ_ROLE:
1777 case AUDIT_SUBJ_TYPE:
1778 case AUDIT_SUBJ_SEN:
1779 case AUDIT_SUBJ_CLR:
1780 case AUDIT_OBJ_USER:
1781 case AUDIT_OBJ_ROLE:
1782 case AUDIT_OBJ_TYPE:
1783 case AUDIT_OBJ_LEV_LOW:
1784 case AUDIT_OBJ_LEV_HIGH:
1792 /* This function will re-initialize the se_rule field of all applicable rules.
1793 * It will traverse the filter lists serarching for rules that contain selinux
1794 * specific filter fields. When such a rule is found, it is copied, the
1795 * selinux field is re-initialized, and the old rule is replaced with the
1797 int selinux_audit_rule_update(void)
1799 struct audit_entry *entry, *n, *nentry;
1800 struct audit_watch *watch;
1801 struct audit_tree *tree;
1804 /* audit_filter_mutex synchronizes the writers */
1805 mutex_lock(&audit_filter_mutex);
1807 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1808 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1809 if (!audit_rule_has_selinux(&entry->rule))
1812 watch = entry->rule.watch;
1813 tree = entry->rule.tree;
1814 nentry = audit_dupe_rule(&entry->rule, watch);
1815 if (unlikely(IS_ERR(nentry))) {
1816 /* save the first error encountered for the
1819 err = PTR_ERR(nentry);
1820 audit_panic("error updating selinux filters");
1822 list_del(&entry->rule.rlist);
1823 list_del_rcu(&entry->list);
1826 list_add(&nentry->rule.rlist,
1828 list_del(&entry->rule.rlist);
1830 list_replace_init(&entry->rule.rlist,
1831 &nentry->rule.rlist);
1832 list_replace_rcu(&entry->list, &nentry->list);
1834 call_rcu(&entry->rcu, audit_free_rule_rcu);
1838 mutex_unlock(&audit_filter_mutex);
1843 /* Update watch data in audit rules based on inotify events. */
1844 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1845 u32 cookie, const char *dname, struct inode *inode)
1847 struct audit_parent *parent;
1849 parent = container_of(i_watch, struct audit_parent, wdata);
1851 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1852 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1854 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1855 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1856 /* inotify automatically removes the watch and sends IN_IGNORED */
1857 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1858 audit_remove_parent_watches(parent);
1859 /* inotify does not remove the watch, so remove it manually */
1860 else if(mask & IN_MOVE_SELF) {
1861 audit_remove_parent_watches(parent);
1862 inotify_remove_watch_locked(audit_ih, i_watch);
1863 } else if (mask & IN_IGNORED)
1864 put_inotify_watch(i_watch);