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/selinux.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 * selinux 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.
50 * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
51 * event. Each audit_watch holds a reference to its associated parent.
53 * audit_watch: if added to lists, lifetime is from audit_init_watch() to
54 * audit_remove_watch(). Additionally, an audit_watch may exist
55 * temporarily to assist in searching existing filter data. Each
56 * audit_krule holds a reference to its associated watch.
60 struct list_head ilist; /* entry in inotify registration list */
61 struct list_head watches; /* associated watches */
62 struct inotify_watch wdata; /* inotify watch data */
63 unsigned flags; /* status flags */
67 * audit_parent status flags:
69 * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
70 * a filesystem event to ensure we're adding audit watches to a valid parent.
71 * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
72 * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
73 * we can receive while holding nameidata.
75 #define AUDIT_PARENT_INVALID 0x001
77 /* Audit filter lists, defined in <linux/audit.h> */
78 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
79 LIST_HEAD_INIT(audit_filter_list[0]),
80 LIST_HEAD_INIT(audit_filter_list[1]),
81 LIST_HEAD_INIT(audit_filter_list[2]),
82 LIST_HEAD_INIT(audit_filter_list[3]),
83 LIST_HEAD_INIT(audit_filter_list[4]),
84 LIST_HEAD_INIT(audit_filter_list[5]),
85 #if AUDIT_NR_FILTERS != 6
86 #error Fix audit_filter_list initialiser
90 static DEFINE_MUTEX(audit_filter_mutex);
93 extern struct inotify_handle *audit_ih;
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
98 void audit_free_parent(struct inotify_watch *i_watch)
100 struct audit_parent *parent;
102 parent = container_of(i_watch, struct audit_parent, wdata);
103 WARN_ON(!list_empty(&parent->watches));
107 static inline void audit_get_watch(struct audit_watch *watch)
109 atomic_inc(&watch->count);
112 static void audit_put_watch(struct audit_watch *watch)
114 if (atomic_dec_and_test(&watch->count)) {
115 WARN_ON(watch->parent);
116 WARN_ON(!list_empty(&watch->rules));
122 static void audit_remove_watch(struct audit_watch *watch)
124 list_del(&watch->wlist);
125 put_inotify_watch(&watch->parent->wdata);
126 watch->parent = NULL;
127 audit_put_watch(watch); /* match initial get */
130 static inline void audit_free_rule(struct audit_entry *e)
134 /* some rules don't have associated watches */
136 audit_put_watch(e->rule.watch);
138 for (i = 0; i < e->rule.field_count; i++) {
139 struct audit_field *f = &e->rule.fields[i];
141 selinux_audit_rule_free(f->se_rule);
143 kfree(e->rule.fields);
144 kfree(e->rule.filterkey);
148 static inline void audit_free_rule_rcu(struct rcu_head *head)
150 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
154 /* Initialize a parent watch entry. */
155 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
157 struct audit_parent *parent;
160 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
161 if (unlikely(!parent))
162 return ERR_PTR(-ENOMEM);
164 INIT_LIST_HEAD(&parent->watches);
167 inotify_init_watch(&parent->wdata);
168 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
169 get_inotify_watch(&parent->wdata);
170 wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
173 audit_free_parent(&parent->wdata);
180 /* Initialize a watch entry. */
181 static struct audit_watch *audit_init_watch(char *path)
183 struct audit_watch *watch;
185 watch = kzalloc(sizeof(*watch), GFP_KERNEL);
186 if (unlikely(!watch))
187 return ERR_PTR(-ENOMEM);
189 INIT_LIST_HEAD(&watch->rules);
190 atomic_set(&watch->count, 1);
192 watch->dev = (dev_t)-1;
193 watch->ino = (unsigned long)-1;
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry *audit_init_entry(u32 field_count)
201 struct audit_entry *entry;
202 struct audit_field *fields;
204 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
205 if (unlikely(!entry))
208 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
209 if (unlikely(!fields)) {
213 entry->rule.fields = fields;
218 /* Unpack a filter field's string representation from user-space
220 static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
224 if (!*bufp || (len == 0) || (len > *remain))
225 return ERR_PTR(-EINVAL);
227 /* Of the currently implemented string fields, PATH_MAX
228 * defines the longest valid length.
231 return ERR_PTR(-ENAMETOOLONG);
233 str = kmalloc(len + 1, GFP_KERNEL);
235 return ERR_PTR(-ENOMEM);
237 memcpy(str, *bufp, len);
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule *krule,
247 struct audit_field *f)
249 if (krule->listnr != AUDIT_FILTER_EXIT ||
250 krule->watch || krule->inode_f)
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
261 struct audit_watch *watch;
266 if (path[0] != '/' || path[len-1] == '/' ||
267 krule->listnr != AUDIT_FILTER_EXIT ||
269 krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
272 watch = audit_init_watch(path);
273 if (unlikely(IS_ERR(watch)))
274 return PTR_ERR(watch);
276 audit_get_watch(watch);
277 krule->watch = watch;
282 /* Common user-space to kernel rule translation. */
283 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
286 struct audit_entry *entry;
290 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
294 case AUDIT_FILTER_USER:
295 case AUDIT_FILTER_TYPE:
296 #ifdef CONFIG_AUDITSYSCALL
297 case AUDIT_FILTER_ENTRY:
298 case AUDIT_FILTER_EXIT:
299 case AUDIT_FILTER_TASK:
303 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
304 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
307 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
309 if (rule->field_count > AUDIT_MAX_FIELDS)
313 entry = audit_init_entry(rule->field_count);
317 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
318 entry->rule.listnr = listnr;
319 entry->rule.action = rule->action;
320 entry->rule.field_count = rule->field_count;
322 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
323 entry->rule.mask[i] = rule->mask[i];
331 /* Translate struct audit_rule to kernel's rule respresentation.
332 * Exists for backward compatibility with userspace. */
333 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
335 struct audit_entry *entry;
336 struct audit_field *f;
340 entry = audit_to_entry_common(rule);
344 for (i = 0; i < rule->field_count; i++) {
345 struct audit_field *f = &entry->rule.fields[i];
347 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
348 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
349 f->val = rule->values[i];
378 err = audit_to_inode(&entry->rule, f);
384 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
386 /* Support for legacy operators where
387 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
388 if (f->op & AUDIT_NEGATE)
389 f->op = AUDIT_NOT_EQUAL;
392 else if (f->op == AUDIT_OPERATORS) {
398 f = entry->rule.inode_f;
401 case AUDIT_NOT_EQUAL:
402 entry->rule.inode_f = NULL;
414 audit_free_rule(entry);
418 /* Translate struct audit_rule_data to kernel's rule respresentation. */
419 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
423 struct audit_entry *entry;
424 struct audit_field *f;
426 size_t remain = datasz - sizeof(struct audit_rule_data);
430 entry = audit_to_entry_common((struct audit_rule *)data);
435 entry->rule.vers_ops = 2;
436 for (i = 0; i < data->field_count; i++) {
437 struct audit_field *f = &entry->rule.fields[i];
440 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
441 data->fieldflags[i] & ~AUDIT_OPERATORS)
444 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
445 f->type = data->fields[i];
446 f->val = data->values[i];
473 case AUDIT_SUBJ_USER:
474 case AUDIT_SUBJ_ROLE:
475 case AUDIT_SUBJ_TYPE:
481 case AUDIT_OBJ_LEV_LOW:
482 case AUDIT_OBJ_LEV_HIGH:
483 str = audit_unpack_string(&bufp, &remain, f->val);
486 entry->rule.buflen += f->val;
488 err = selinux_audit_rule_init(f->type, f->op, str,
490 /* Keep currently invalid fields around in case they
491 * become valid after a policy reload. */
492 if (err == -EINVAL) {
493 printk(KERN_WARNING "audit rule for selinux "
494 "\'%s\' is invalid\n", str);
504 str = audit_unpack_string(&bufp, &remain, f->val);
507 entry->rule.buflen += f->val;
509 err = audit_to_watch(&entry->rule, str, f->val, f->op);
516 err = audit_to_inode(&entry->rule, f);
520 case AUDIT_FILTERKEY:
522 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
524 str = audit_unpack_string(&bufp, &remain, f->val);
527 entry->rule.buflen += f->val;
528 entry->rule.filterkey = str;
535 f = entry->rule.inode_f;
538 case AUDIT_NOT_EQUAL:
539 entry->rule.inode_f = NULL;
551 audit_free_rule(entry);
555 /* Pack a filter field's string representation into data block. */
556 static inline size_t audit_pack_string(void **bufp, char *str)
558 size_t len = strlen(str);
560 memcpy(*bufp, str, len);
566 /* Translate kernel rule respresentation to struct audit_rule.
567 * Exists for backward compatibility with userspace. */
568 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
570 struct audit_rule *rule;
573 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
576 memset(rule, 0, sizeof(*rule));
578 rule->flags = krule->flags | krule->listnr;
579 rule->action = krule->action;
580 rule->field_count = krule->field_count;
581 for (i = 0; i < rule->field_count; i++) {
582 rule->values[i] = krule->fields[i].val;
583 rule->fields[i] = krule->fields[i].type;
585 if (krule->vers_ops == 1) {
586 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
587 rule->fields[i] |= AUDIT_NEGATE;
589 rule->fields[i] |= krule->fields[i].op;
592 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
597 /* Translate kernel rule respresentation to struct audit_rule_data. */
598 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
600 struct audit_rule_data *data;
604 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
607 memset(data, 0, sizeof(*data));
609 data->flags = krule->flags | krule->listnr;
610 data->action = krule->action;
611 data->field_count = krule->field_count;
613 for (i = 0; i < data->field_count; i++) {
614 struct audit_field *f = &krule->fields[i];
616 data->fields[i] = f->type;
617 data->fieldflags[i] = f->op;
619 case AUDIT_SUBJ_USER:
620 case AUDIT_SUBJ_ROLE:
621 case AUDIT_SUBJ_TYPE:
627 case AUDIT_OBJ_LEV_LOW:
628 case AUDIT_OBJ_LEV_HIGH:
629 data->buflen += data->values[i] =
630 audit_pack_string(&bufp, f->se_str);
633 data->buflen += data->values[i] =
634 audit_pack_string(&bufp, krule->watch->path);
636 case AUDIT_FILTERKEY:
637 data->buflen += data->values[i] =
638 audit_pack_string(&bufp, krule->filterkey);
641 data->values[i] = f->val;
644 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
649 /* Compare two rules in kernel format. Considered success if rules
651 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
655 if (a->flags != b->flags ||
656 a->listnr != b->listnr ||
657 a->action != b->action ||
658 a->field_count != b->field_count)
661 for (i = 0; i < a->field_count; i++) {
662 if (a->fields[i].type != b->fields[i].type ||
663 a->fields[i].op != b->fields[i].op)
666 switch(a->fields[i].type) {
667 case AUDIT_SUBJ_USER:
668 case AUDIT_SUBJ_ROLE:
669 case AUDIT_SUBJ_TYPE:
675 case AUDIT_OBJ_LEV_LOW:
676 case AUDIT_OBJ_LEV_HIGH:
677 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
681 if (strcmp(a->watch->path, b->watch->path))
684 case AUDIT_FILTERKEY:
685 /* both filterkeys exist based on above type compare */
686 if (strcmp(a->filterkey, b->filterkey))
690 if (a->fields[i].val != b->fields[i].val)
695 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
696 if (a->mask[i] != b->mask[i])
702 /* Duplicate the given audit watch. The new watch's rules list is initialized
703 * to an empty list and wlist is undefined. */
704 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
707 struct audit_watch *new;
709 path = kstrdup(old->path, GFP_KERNEL);
711 return ERR_PTR(-ENOMEM);
713 new = audit_init_watch(path);
714 if (unlikely(IS_ERR(new))) {
721 get_inotify_watch(&old->parent->wdata);
722 new->parent = old->parent;
728 /* Duplicate selinux field information. The se_rule is opaque, so must be
730 static inline int audit_dupe_selinux_field(struct audit_field *df,
731 struct audit_field *sf)
736 /* our own copy of se_str */
737 se_str = kstrdup(sf->se_str, GFP_KERNEL);
738 if (unlikely(IS_ERR(se_str)))
742 /* our own (refreshed) copy of se_rule */
743 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
745 /* Keep currently invalid fields around in case they
746 * become valid after a policy reload. */
747 if (ret == -EINVAL) {
748 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
749 "invalid\n", df->se_str);
756 /* Duplicate an audit rule. This will be a deep copy with the exception
757 * of the watch - that pointer is carried over. The selinux specific fields
758 * will be updated in the copy. The point is to be able to replace the old
759 * rule with the new rule in the filterlist, then free the old rule.
760 * The rlist element is undefined; list manipulations are handled apart from
761 * the initial copy. */
762 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
763 struct audit_watch *watch)
765 u32 fcount = old->field_count;
766 struct audit_entry *entry;
767 struct audit_krule *new;
771 entry = audit_init_entry(fcount);
772 if (unlikely(!entry))
773 return ERR_PTR(-ENOMEM);
776 new->vers_ops = old->vers_ops;
777 new->flags = old->flags;
778 new->listnr = old->listnr;
779 new->action = old->action;
780 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
781 new->mask[i] = old->mask[i];
782 new->buflen = old->buflen;
783 new->inode_f = old->inode_f;
785 new->field_count = old->field_count;
786 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
788 /* deep copy this information, updating the se_rule fields, because
789 * the originals will all be freed when the old rule is freed. */
790 for (i = 0; i < fcount; i++) {
791 switch (new->fields[i].type) {
792 case AUDIT_SUBJ_USER:
793 case AUDIT_SUBJ_ROLE:
794 case AUDIT_SUBJ_TYPE:
800 case AUDIT_OBJ_LEV_LOW:
801 case AUDIT_OBJ_LEV_HIGH:
802 err = audit_dupe_selinux_field(&new->fields[i],
805 case AUDIT_FILTERKEY:
806 fk = kstrdup(old->filterkey, GFP_KERNEL);
813 audit_free_rule(entry);
819 audit_get_watch(watch);
826 /* Update inode info in audit rules based on filesystem event. */
827 static void audit_update_watch(struct audit_parent *parent,
828 const char *dname, dev_t dev,
829 unsigned long ino, unsigned invalidating)
831 struct audit_watch *owatch, *nwatch, *nextw;
832 struct audit_krule *r, *nextr;
833 struct audit_entry *oentry, *nentry;
834 struct audit_buffer *ab;
836 mutex_lock(&audit_filter_mutex);
837 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
838 if (audit_compare_dname_path(dname, owatch->path, NULL))
841 /* If the update involves invalidating rules, do the inode-based
842 * filtering now, so we don't omit records. */
844 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
845 audit_set_auditable(current->audit_context);
847 nwatch = audit_dupe_watch(owatch);
848 if (unlikely(IS_ERR(nwatch))) {
849 mutex_unlock(&audit_filter_mutex);
850 audit_panic("error updating watch, skipping");
856 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
858 oentry = container_of(r, struct audit_entry, rule);
859 list_del(&oentry->rule.rlist);
860 list_del_rcu(&oentry->list);
862 nentry = audit_dupe_rule(&oentry->rule, nwatch);
863 if (unlikely(IS_ERR(nentry)))
864 audit_panic("error updating watch, removing");
866 int h = audit_hash_ino((u32)ino);
867 list_add(&nentry->rule.rlist, &nwatch->rules);
868 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
871 call_rcu(&oentry->rcu, audit_free_rule_rcu);
874 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
875 audit_log_format(ab, "audit updated rules specifying watch=");
876 audit_log_untrustedstring(ab, owatch->path);
877 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
880 audit_remove_watch(owatch);
881 goto add_watch_to_parent; /* event applies to a single watch */
883 mutex_unlock(&audit_filter_mutex);
887 list_add(&nwatch->wlist, &parent->watches);
888 mutex_unlock(&audit_filter_mutex);
892 /* Remove all watches & rules associated with a parent that is going away. */
893 static void audit_remove_parent_watches(struct audit_parent *parent)
895 struct audit_watch *w, *nextw;
896 struct audit_krule *r, *nextr;
897 struct audit_entry *e;
899 mutex_lock(&audit_filter_mutex);
900 parent->flags |= AUDIT_PARENT_INVALID;
901 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
902 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
903 e = container_of(r, struct audit_entry, rule);
905 list_del_rcu(&e->list);
906 call_rcu(&e->rcu, audit_free_rule_rcu);
908 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
909 "audit implicitly removed rule from list=%d\n",
912 audit_remove_watch(w);
914 mutex_unlock(&audit_filter_mutex);
917 /* Unregister inotify watches for parents on in_list.
918 * Generates an IN_IGNORED event. */
919 static void audit_inotify_unregister(struct list_head *in_list)
921 struct audit_parent *p, *n;
923 list_for_each_entry_safe(p, n, in_list, ilist) {
925 inotify_rm_watch(audit_ih, &p->wdata);
926 /* the put matching the get in audit_do_del_rule() */
927 put_inotify_watch(&p->wdata);
931 /* Find an existing audit rule.
932 * Caller must hold audit_filter_mutex to prevent stale rule data. */
933 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
934 struct list_head *list)
936 struct audit_entry *e, *found = NULL;
939 if (entry->rule.watch) {
940 /* we don't know the inode number, so must walk entire hash */
941 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
942 list = &audit_inode_hash[h];
943 list_for_each_entry(e, list, list)
944 if (!audit_compare_rule(&entry->rule, &e->rule)) {
952 list_for_each_entry(e, list, list)
953 if (!audit_compare_rule(&entry->rule, &e->rule)) {
962 /* Get path information necessary for adding watches. */
963 static int audit_get_nd(char *path, struct nameidata **ndp,
964 struct nameidata **ndw)
966 struct nameidata *ndparent, *ndwatch;
969 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
970 if (unlikely(!ndparent))
973 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
974 if (unlikely(!ndwatch)) {
979 err = path_lookup(path, LOOKUP_PARENT, ndparent);
986 err = path_lookup(path, 0, ndwatch);
998 /* Release resources used for watch path information. */
999 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
1011 /* Associate the given rule with an existing parent inotify_watch.
1012 * Caller must hold audit_filter_mutex. */
1013 static void audit_add_to_parent(struct audit_krule *krule,
1014 struct audit_parent *parent)
1016 struct audit_watch *w, *watch = krule->watch;
1017 int watch_found = 0;
1019 list_for_each_entry(w, &parent->watches, wlist) {
1020 if (strcmp(watch->path, w->path))
1025 /* put krule's and initial refs to temporary watch */
1026 audit_put_watch(watch);
1027 audit_put_watch(watch);
1030 krule->watch = watch = w;
1035 get_inotify_watch(&parent->wdata);
1036 watch->parent = parent;
1038 list_add(&watch->wlist, &parent->watches);
1040 list_add(&krule->rlist, &watch->rules);
1043 /* Find a matching watch entry, or add this one.
1044 * Caller must hold audit_filter_mutex. */
1045 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
1046 struct nameidata *ndw)
1048 struct audit_watch *watch = krule->watch;
1049 struct inotify_watch *i_watch;
1050 struct audit_parent *parent;
1053 /* update watch filter fields */
1055 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1056 watch->ino = ndw->dentry->d_inode->i_ino;
1059 /* The audit_filter_mutex must not be held during inotify calls because
1060 * we hold it during inotify event callback processing. If an existing
1061 * inotify watch is found, inotify_find_watch() grabs a reference before
1064 mutex_unlock(&audit_filter_mutex);
1066 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1067 parent = audit_init_parent(ndp);
1068 if (IS_ERR(parent)) {
1069 /* caller expects mutex locked */
1070 mutex_lock(&audit_filter_mutex);
1071 return PTR_ERR(parent);
1074 parent = container_of(i_watch, struct audit_parent, wdata);
1076 mutex_lock(&audit_filter_mutex);
1078 /* parent was moved before we took audit_filter_mutex */
1079 if (parent->flags & AUDIT_PARENT_INVALID)
1082 audit_add_to_parent(krule, parent);
1084 /* match get in audit_init_parent or inotify_find_watch */
1085 put_inotify_watch(&parent->wdata);
1089 /* Add rule to given filterlist if not a duplicate. */
1090 static inline int audit_add_rule(struct audit_entry *entry,
1091 struct list_head *list)
1093 struct audit_entry *e;
1094 struct audit_field *inode_f = entry->rule.inode_f;
1095 struct audit_watch *watch = entry->rule.watch;
1096 struct nameidata *ndp, *ndw;
1097 int h, err, putnd_needed = 0;
1100 h = audit_hash_ino(inode_f->val);
1101 list = &audit_inode_hash[h];
1104 mutex_lock(&audit_filter_mutex);
1105 e = audit_find_rule(entry, list);
1106 mutex_unlock(&audit_filter_mutex);
1112 /* Avoid calling path_lookup under audit_filter_mutex. */
1114 err = audit_get_nd(watch->path, &ndp, &ndw);
1120 mutex_lock(&audit_filter_mutex);
1122 /* audit_filter_mutex is dropped and re-taken during this call */
1123 err = audit_add_watch(&entry->rule, ndp, ndw);
1125 mutex_unlock(&audit_filter_mutex);
1128 h = audit_hash_ino((u32)watch->ino);
1129 list = &audit_inode_hash[h];
1132 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1133 list_add_rcu(&entry->list, list);
1134 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1136 list_add_tail_rcu(&entry->list, list);
1138 mutex_unlock(&audit_filter_mutex);
1141 audit_put_nd(ndp, ndw);
1147 audit_put_nd(ndp, ndw);
1149 audit_put_watch(watch); /* tmp watch, matches initial get */
1153 /* Remove an existing rule from filterlist. */
1154 static inline int audit_del_rule(struct audit_entry *entry,
1155 struct list_head *list)
1157 struct audit_entry *e;
1158 struct audit_field *inode_f = entry->rule.inode_f;
1159 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1160 LIST_HEAD(inotify_list);
1164 h = audit_hash_ino(inode_f->val);
1165 list = &audit_inode_hash[h];
1168 mutex_lock(&audit_filter_mutex);
1169 e = audit_find_rule(entry, list);
1171 mutex_unlock(&audit_filter_mutex);
1176 watch = e->rule.watch;
1178 struct audit_parent *parent = watch->parent;
1180 list_del(&e->rule.rlist);
1182 if (list_empty(&watch->rules)) {
1183 audit_remove_watch(watch);
1185 if (list_empty(&parent->watches)) {
1186 /* Put parent on the inotify un-registration
1187 * list. Grab a reference before releasing
1188 * audit_filter_mutex, to be released in
1189 * audit_inotify_unregister(). */
1190 list_add(&parent->ilist, &inotify_list);
1191 get_inotify_watch(&parent->wdata);
1196 list_del_rcu(&e->list);
1197 call_rcu(&e->rcu, audit_free_rule_rcu);
1199 mutex_unlock(&audit_filter_mutex);
1201 if (!list_empty(&inotify_list))
1202 audit_inotify_unregister(&inotify_list);
1206 audit_put_watch(tmp_watch); /* match initial get */
1211 /* List rules using struct audit_rule. Exists for backward
1212 * compatibility with userspace. */
1213 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1215 struct sk_buff *skb;
1216 struct audit_entry *entry;
1219 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1220 * iterator to sync with list writers. */
1221 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1222 list_for_each_entry(entry, &audit_filter_list[i], list) {
1223 struct audit_rule *rule;
1225 rule = audit_krule_to_rule(&entry->rule);
1226 if (unlikely(!rule))
1228 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1229 rule, sizeof(*rule));
1231 skb_queue_tail(q, skb);
1235 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1236 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1237 struct audit_rule *rule;
1239 rule = audit_krule_to_rule(&entry->rule);
1240 if (unlikely(!rule))
1242 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1243 rule, sizeof(*rule));
1245 skb_queue_tail(q, skb);
1249 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1251 skb_queue_tail(q, skb);
1254 /* List rules using struct audit_rule_data. */
1255 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1257 struct sk_buff *skb;
1258 struct audit_entry *e;
1261 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1262 * iterator to sync with list writers. */
1263 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1264 list_for_each_entry(e, &audit_filter_list[i], list) {
1265 struct audit_rule_data *data;
1267 data = audit_krule_to_data(&e->rule);
1268 if (unlikely(!data))
1270 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1271 data, sizeof(*data) + data->buflen);
1273 skb_queue_tail(q, skb);
1277 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1278 list_for_each_entry(e, &audit_inode_hash[i], list) {
1279 struct audit_rule_data *data;
1281 data = audit_krule_to_data(&e->rule);
1282 if (unlikely(!data))
1284 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1285 data, sizeof(*data) + data->buflen);
1287 skb_queue_tail(q, skb);
1291 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1293 skb_queue_tail(q, skb);
1296 /* Log rule additions and removals */
1297 static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action,
1298 struct audit_krule *rule, int res)
1300 struct audit_buffer *ab;
1302 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1305 audit_log_format(ab, "auid=%u", loginuid);
1309 if (selinux_ctxid_to_string(sid, &ctx, &len))
1310 audit_log_format(ab, " ssid=%u", sid);
1312 audit_log_format(ab, " subj=%s", ctx);
1315 audit_log_format(ab, " %s rule key=", action);
1316 if (rule->filterkey)
1317 audit_log_untrustedstring(ab, rule->filterkey);
1319 audit_log_format(ab, "(null)");
1320 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1325 * audit_receive_filter - apply all rules to the specified message type
1326 * @type: audit message type
1327 * @pid: target pid for netlink audit messages
1328 * @uid: target uid for netlink audit messages
1329 * @seq: netlink audit message sequence (serial) number
1330 * @data: payload data
1331 * @datasz: size of payload data
1332 * @loginuid: loginuid of sender
1333 * @sid: SE Linux Security ID of sender
1335 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1336 size_t datasz, uid_t loginuid, u32 sid)
1338 struct task_struct *tsk;
1339 struct audit_netlink_list *dest;
1341 struct audit_entry *entry;
1345 case AUDIT_LIST_RULES:
1346 /* We can't just spew out the rules here because we might fill
1347 * the available socket buffer space and deadlock waiting for
1348 * auditctl to read from it... which isn't ever going to
1349 * happen if we're actually running in the context of auditctl
1350 * trying to _send_ the stuff */
1352 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1356 skb_queue_head_init(&dest->q);
1358 mutex_lock(&audit_filter_mutex);
1359 if (type == AUDIT_LIST)
1360 audit_list(pid, seq, &dest->q);
1362 audit_list_rules(pid, seq, &dest->q);
1363 mutex_unlock(&audit_filter_mutex);
1365 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1367 skb_queue_purge(&dest->q);
1373 case AUDIT_ADD_RULE:
1374 if (type == AUDIT_ADD)
1375 entry = audit_rule_to_entry(data);
1377 entry = audit_data_to_entry(data, datasz);
1379 return PTR_ERR(entry);
1381 err = audit_add_rule(entry,
1382 &audit_filter_list[entry->rule.listnr]);
1383 audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err);
1386 audit_free_rule(entry);
1389 case AUDIT_DEL_RULE:
1390 if (type == AUDIT_DEL)
1391 entry = audit_rule_to_entry(data);
1393 entry = audit_data_to_entry(data, datasz);
1395 return PTR_ERR(entry);
1397 err = audit_del_rule(entry,
1398 &audit_filter_list[entry->rule.listnr]);
1399 audit_log_rule_change(loginuid, sid, "remove", &entry->rule,
1402 audit_free_rule(entry);
1411 int audit_comparator(const u32 left, const u32 op, const u32 right)
1415 return (left == right);
1416 case AUDIT_NOT_EQUAL:
1417 return (left != right);
1418 case AUDIT_LESS_THAN:
1419 return (left < right);
1420 case AUDIT_LESS_THAN_OR_EQUAL:
1421 return (left <= right);
1422 case AUDIT_GREATER_THAN:
1423 return (left > right);
1424 case AUDIT_GREATER_THAN_OR_EQUAL:
1425 return (left >= right);
1431 /* Compare given dentry name with last component in given path,
1432 * return of 0 indicates a match. */
1433 int audit_compare_dname_path(const char *dname, const char *path,
1439 if (!dname || !path)
1442 dlen = strlen(dname);
1443 plen = strlen(path);
1447 /* disregard trailing slashes */
1448 p = path + plen - 1;
1449 while ((*p == '/') && (p > path))
1452 /* find last path component */
1456 else if (p > path) {
1463 /* return length of path's directory component */
1466 return strncmp(p, dname, dlen);
1469 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1470 struct audit_krule *rule,
1471 enum audit_state *state)
1475 for (i = 0; i < rule->field_count; i++) {
1476 struct audit_field *f = &rule->fields[i];
1481 result = audit_comparator(cb->creds.pid, f->op, f->val);
1484 result = audit_comparator(cb->creds.uid, f->op, f->val);
1487 result = audit_comparator(cb->creds.gid, f->op, f->val);
1489 case AUDIT_LOGINUID:
1490 result = audit_comparator(cb->loginuid, f->op, f->val);
1497 switch (rule->action) {
1498 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1499 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1504 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1506 struct audit_entry *e;
1507 enum audit_state state;
1511 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1512 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1513 if (state == AUDIT_DISABLED)
1520 return ret; /* Audit by default */
1523 int audit_filter_type(int type)
1525 struct audit_entry *e;
1529 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1530 goto unlock_and_return;
1532 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1535 for (i = 0; i < e->rule.field_count; i++) {
1536 struct audit_field *f = &e->rule.fields[i];
1537 if (f->type == AUDIT_MSGTYPE) {
1538 result = audit_comparator(type, f->op, f->val);
1544 goto unlock_and_return;
1551 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1552 are selinux fields specified in the rule, 0 otherwise. */
1553 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1557 for (i = 0; i < rule->field_count; i++) {
1558 struct audit_field *f = &rule->fields[i];
1560 case AUDIT_SUBJ_USER:
1561 case AUDIT_SUBJ_ROLE:
1562 case AUDIT_SUBJ_TYPE:
1563 case AUDIT_SUBJ_SEN:
1564 case AUDIT_SUBJ_CLR:
1565 case AUDIT_OBJ_USER:
1566 case AUDIT_OBJ_ROLE:
1567 case AUDIT_OBJ_TYPE:
1568 case AUDIT_OBJ_LEV_LOW:
1569 case AUDIT_OBJ_LEV_HIGH:
1577 /* This function will re-initialize the se_rule field of all applicable rules.
1578 * It will traverse the filter lists serarching for rules that contain selinux
1579 * specific filter fields. When such a rule is found, it is copied, the
1580 * selinux field is re-initialized, and the old rule is replaced with the
1582 int selinux_audit_rule_update(void)
1584 struct audit_entry *entry, *n, *nentry;
1585 struct audit_watch *watch;
1588 /* audit_filter_mutex synchronizes the writers */
1589 mutex_lock(&audit_filter_mutex);
1591 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1592 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1593 if (!audit_rule_has_selinux(&entry->rule))
1596 watch = entry->rule.watch;
1597 nentry = audit_dupe_rule(&entry->rule, watch);
1598 if (unlikely(IS_ERR(nentry))) {
1599 /* save the first error encountered for the
1602 err = PTR_ERR(nentry);
1603 audit_panic("error updating selinux filters");
1605 list_del(&entry->rule.rlist);
1606 list_del_rcu(&entry->list);
1609 list_add(&nentry->rule.rlist,
1611 list_del(&entry->rule.rlist);
1613 list_replace_rcu(&entry->list, &nentry->list);
1615 call_rcu(&entry->rcu, audit_free_rule_rcu);
1619 mutex_unlock(&audit_filter_mutex);
1624 /* Update watch data in audit rules based on inotify events. */
1625 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1626 u32 cookie, const char *dname, struct inode *inode)
1628 struct audit_parent *parent;
1630 parent = container_of(i_watch, struct audit_parent, wdata);
1632 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1633 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1635 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1636 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1637 /* inotify automatically removes the watch and sends IN_IGNORED */
1638 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1639 audit_remove_parent_watches(parent);
1640 /* inotify does not remove the watch, so remove it manually */
1641 else if(mask & IN_MOVE_SELF) {
1642 audit_remove_parent_watches(parent);
1643 inotify_remove_watch_locked(audit_ih, i_watch);
1644 } else if (mask & IN_IGNORED)
1645 put_inotify_watch(i_watch);