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);
147 static inline void audit_free_rule_rcu(struct rcu_head *head)
149 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
153 /* Initialize a parent watch entry. */
154 static struct audit_parent *audit_init_parent(struct nameidata *ndp)
156 struct audit_parent *parent;
159 parent = kzalloc(sizeof(*parent), GFP_KERNEL);
160 if (unlikely(!parent))
161 return ERR_PTR(-ENOMEM);
163 INIT_LIST_HEAD(&parent->watches);
166 inotify_init_watch(&parent->wdata);
167 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
168 get_inotify_watch(&parent->wdata);
169 wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode,
172 audit_free_parent(&parent->wdata);
179 /* Initialize a watch entry. */
180 static struct audit_watch *audit_init_watch(char *path)
182 struct audit_watch *watch;
184 watch = kzalloc(sizeof(*watch), GFP_KERNEL);
185 if (unlikely(!watch))
186 return ERR_PTR(-ENOMEM);
188 INIT_LIST_HEAD(&watch->rules);
189 atomic_set(&watch->count, 1);
191 watch->dev = (dev_t)-1;
192 watch->ino = (unsigned long)-1;
197 /* Initialize an audit filterlist entry. */
198 static inline struct audit_entry *audit_init_entry(u32 field_count)
200 struct audit_entry *entry;
201 struct audit_field *fields;
203 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
204 if (unlikely(!entry))
207 fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
208 if (unlikely(!fields)) {
212 entry->rule.fields = fields;
217 /* Unpack a filter field's string representation from user-space
219 static char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
223 if (!*bufp || (len == 0) || (len > *remain))
224 return ERR_PTR(-EINVAL);
226 /* Of the currently implemented string fields, PATH_MAX
227 * defines the longest valid length.
230 return ERR_PTR(-ENAMETOOLONG);
232 str = kmalloc(len + 1, GFP_KERNEL);
234 return ERR_PTR(-ENOMEM);
236 memcpy(str, *bufp, len);
244 /* Translate an inode field to kernel respresentation. */
245 static inline int audit_to_inode(struct audit_krule *krule,
246 struct audit_field *f)
248 if (krule->listnr != AUDIT_FILTER_EXIT ||
249 krule->watch || krule->inode_f)
256 /* Translate a watch string to kernel respresentation. */
257 static int audit_to_watch(struct audit_krule *krule, char *path, int len,
260 struct audit_watch *watch;
265 if (path[0] != '/' || path[len-1] == '/' ||
266 krule->listnr != AUDIT_FILTER_EXIT ||
268 krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */
271 watch = audit_init_watch(path);
272 if (unlikely(IS_ERR(watch)))
273 return PTR_ERR(watch);
275 audit_get_watch(watch);
276 krule->watch = watch;
281 /* Common user-space to kernel rule translation. */
282 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
285 struct audit_entry *entry;
289 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
293 case AUDIT_FILTER_USER:
294 case AUDIT_FILTER_TYPE:
295 #ifdef CONFIG_AUDITSYSCALL
296 case AUDIT_FILTER_ENTRY:
297 case AUDIT_FILTER_EXIT:
298 case AUDIT_FILTER_TASK:
302 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
303 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
306 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
308 if (rule->field_count > AUDIT_MAX_FIELDS)
312 entry = audit_init_entry(rule->field_count);
316 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
317 entry->rule.listnr = listnr;
318 entry->rule.action = rule->action;
319 entry->rule.field_count = rule->field_count;
321 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
322 entry->rule.mask[i] = rule->mask[i];
330 /* Translate struct audit_rule to kernel's rule respresentation.
331 * Exists for backward compatibility with userspace. */
332 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
334 struct audit_entry *entry;
335 struct audit_field *f;
339 entry = audit_to_entry_common(rule);
343 for (i = 0; i < rule->field_count; i++) {
344 struct audit_field *f = &entry->rule.fields[i];
346 f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
347 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
348 f->val = rule->values[i];
377 err = audit_to_inode(&entry->rule, f);
383 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
385 /* Support for legacy operators where
386 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
387 if (f->op & AUDIT_NEGATE)
388 f->op = AUDIT_NOT_EQUAL;
391 else if (f->op == AUDIT_OPERATORS) {
397 f = entry->rule.inode_f;
400 case AUDIT_NOT_EQUAL:
401 entry->rule.inode_f = NULL;
413 audit_free_rule(entry);
417 /* Translate struct audit_rule_data to kernel's rule respresentation. */
418 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
422 struct audit_entry *entry;
423 struct audit_field *f;
425 size_t remain = datasz - sizeof(struct audit_rule_data);
429 entry = audit_to_entry_common((struct audit_rule *)data);
434 entry->rule.vers_ops = 2;
435 for (i = 0; i < data->field_count; i++) {
436 struct audit_field *f = &entry->rule.fields[i];
439 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
440 data->fieldflags[i] & ~AUDIT_OPERATORS)
443 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
444 f->type = data->fields[i];
445 f->val = data->values[i];
477 str = audit_unpack_string(&bufp, &remain, f->val);
480 entry->rule.buflen += f->val;
482 err = selinux_audit_rule_init(f->type, f->op, str,
484 /* Keep currently invalid fields around in case they
485 * become valid after a policy reload. */
486 if (err == -EINVAL) {
487 printk(KERN_WARNING "audit rule for selinux "
488 "\'%s\' is invalid\n", str);
498 str = audit_unpack_string(&bufp, &remain, f->val);
501 entry->rule.buflen += f->val;
503 err = audit_to_watch(&entry->rule, str, f->val, f->op);
510 err = audit_to_inode(&entry->rule, f);
519 f = entry->rule.inode_f;
522 case AUDIT_NOT_EQUAL:
523 entry->rule.inode_f = NULL;
535 audit_free_rule(entry);
539 /* Pack a filter field's string representation into data block. */
540 static inline size_t audit_pack_string(void **bufp, char *str)
542 size_t len = strlen(str);
544 memcpy(*bufp, str, len);
550 /* Translate kernel rule respresentation to struct audit_rule.
551 * Exists for backward compatibility with userspace. */
552 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
554 struct audit_rule *rule;
557 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
560 memset(rule, 0, sizeof(*rule));
562 rule->flags = krule->flags | krule->listnr;
563 rule->action = krule->action;
564 rule->field_count = krule->field_count;
565 for (i = 0; i < rule->field_count; i++) {
566 rule->values[i] = krule->fields[i].val;
567 rule->fields[i] = krule->fields[i].type;
569 if (krule->vers_ops == 1) {
570 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
571 rule->fields[i] |= AUDIT_NEGATE;
573 rule->fields[i] |= krule->fields[i].op;
576 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
581 /* Translate kernel rule respresentation to struct audit_rule_data. */
582 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
584 struct audit_rule_data *data;
588 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
591 memset(data, 0, sizeof(*data));
593 data->flags = krule->flags | krule->listnr;
594 data->action = krule->action;
595 data->field_count = krule->field_count;
597 for (i = 0; i < data->field_count; i++) {
598 struct audit_field *f = &krule->fields[i];
600 data->fields[i] = f->type;
601 data->fieldflags[i] = f->op;
608 data->buflen += data->values[i] =
609 audit_pack_string(&bufp, f->se_str);
612 data->buflen += data->values[i] =
613 audit_pack_string(&bufp, krule->watch->path);
616 data->values[i] = f->val;
619 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
624 /* Compare two rules in kernel format. Considered success if rules
626 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
630 if (a->flags != b->flags ||
631 a->listnr != b->listnr ||
632 a->action != b->action ||
633 a->field_count != b->field_count)
636 for (i = 0; i < a->field_count; i++) {
637 if (a->fields[i].type != b->fields[i].type ||
638 a->fields[i].op != b->fields[i].op)
641 switch(a->fields[i].type) {
647 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
651 if (strcmp(a->watch->path, b->watch->path))
655 if (a->fields[i].val != b->fields[i].val)
660 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
661 if (a->mask[i] != b->mask[i])
667 /* Duplicate the given audit watch. The new watch's rules list is initialized
668 * to an empty list and wlist is undefined. */
669 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
672 struct audit_watch *new;
674 path = kstrdup(old->path, GFP_KERNEL);
676 return ERR_PTR(-ENOMEM);
678 new = audit_init_watch(path);
679 if (unlikely(IS_ERR(new))) {
686 get_inotify_watch(&old->parent->wdata);
687 new->parent = old->parent;
693 /* Duplicate selinux field information. The se_rule is opaque, so must be
695 static inline int audit_dupe_selinux_field(struct audit_field *df,
696 struct audit_field *sf)
701 /* our own copy of se_str */
702 se_str = kstrdup(sf->se_str, GFP_KERNEL);
703 if (unlikely(IS_ERR(se_str)))
707 /* our own (refreshed) copy of se_rule */
708 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
710 /* Keep currently invalid fields around in case they
711 * become valid after a policy reload. */
712 if (ret == -EINVAL) {
713 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
714 "invalid\n", df->se_str);
721 /* Duplicate an audit rule. This will be a deep copy with the exception
722 * of the watch - that pointer is carried over. The selinux specific fields
723 * will be updated in the copy. The point is to be able to replace the old
724 * rule with the new rule in the filterlist, then free the old rule.
725 * The rlist element is undefined; list manipulations are handled apart from
726 * the initial copy. */
727 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
728 struct audit_watch *watch)
730 u32 fcount = old->field_count;
731 struct audit_entry *entry;
732 struct audit_krule *new;
735 entry = audit_init_entry(fcount);
736 if (unlikely(!entry))
737 return ERR_PTR(-ENOMEM);
740 new->vers_ops = old->vers_ops;
741 new->flags = old->flags;
742 new->listnr = old->listnr;
743 new->action = old->action;
744 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
745 new->mask[i] = old->mask[i];
746 new->buflen = old->buflen;
747 new->inode_f = old->inode_f;
749 new->field_count = old->field_count;
750 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
752 /* deep copy this information, updating the se_rule fields, because
753 * the originals will all be freed when the old rule is freed. */
754 for (i = 0; i < fcount; i++) {
755 switch (new->fields[i].type) {
761 err = audit_dupe_selinux_field(&new->fields[i],
765 audit_free_rule(entry);
771 audit_get_watch(watch);
778 /* Update inode info in audit rules based on filesystem event. */
779 static void audit_update_watch(struct audit_parent *parent,
780 const char *dname, dev_t dev,
781 unsigned long ino, unsigned invalidating)
783 struct audit_watch *owatch, *nwatch, *nextw;
784 struct audit_krule *r, *nextr;
785 struct audit_entry *oentry, *nentry;
786 struct audit_buffer *ab;
788 mutex_lock(&audit_filter_mutex);
789 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
790 if (audit_compare_dname_path(dname, owatch->path))
793 /* If the update involves invalidating rules, do the inode-based
794 * filtering now, so we don't omit records. */
796 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
797 audit_set_auditable(current->audit_context);
799 nwatch = audit_dupe_watch(owatch);
800 if (unlikely(IS_ERR(nwatch))) {
801 mutex_unlock(&audit_filter_mutex);
802 audit_panic("error updating watch, skipping");
808 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
810 oentry = container_of(r, struct audit_entry, rule);
811 list_del(&oentry->rule.rlist);
812 list_del_rcu(&oentry->list);
814 nentry = audit_dupe_rule(&oentry->rule, nwatch);
815 if (unlikely(IS_ERR(nentry)))
816 audit_panic("error updating watch, removing");
818 int h = audit_hash_ino((u32)ino);
819 list_add(&nentry->rule.rlist, &nwatch->rules);
820 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
823 call_rcu(&oentry->rcu, audit_free_rule_rcu);
826 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
827 audit_log_format(ab, "audit updated rules specifying watch=");
828 audit_log_untrustedstring(ab, owatch->path);
829 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
832 audit_remove_watch(owatch);
833 goto add_watch_to_parent; /* event applies to a single watch */
835 mutex_unlock(&audit_filter_mutex);
839 list_add(&nwatch->wlist, &parent->watches);
840 mutex_unlock(&audit_filter_mutex);
844 /* Remove all watches & rules associated with a parent that is going away. */
845 static void audit_remove_parent_watches(struct audit_parent *parent)
847 struct audit_watch *w, *nextw;
848 struct audit_krule *r, *nextr;
849 struct audit_entry *e;
851 mutex_lock(&audit_filter_mutex);
852 parent->flags |= AUDIT_PARENT_INVALID;
853 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
854 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
855 e = container_of(r, struct audit_entry, rule);
857 list_del_rcu(&e->list);
858 call_rcu(&e->rcu, audit_free_rule_rcu);
860 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
861 "audit implicitly removed rule from list=%d\n",
864 audit_remove_watch(w);
866 mutex_unlock(&audit_filter_mutex);
869 /* Unregister inotify watches for parents on in_list.
870 * Generates an IN_IGNORED event. */
871 static void audit_inotify_unregister(struct list_head *in_list)
873 struct audit_parent *p, *n;
875 list_for_each_entry_safe(p, n, in_list, ilist) {
877 inotify_rm_watch(audit_ih, &p->wdata);
878 /* the put matching the get in audit_do_del_rule() */
879 put_inotify_watch(&p->wdata);
883 /* Find an existing audit rule.
884 * Caller must hold audit_filter_mutex to prevent stale rule data. */
885 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
886 struct list_head *list)
888 struct audit_entry *e, *found = NULL;
891 if (entry->rule.watch) {
892 /* we don't know the inode number, so must walk entire hash */
893 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
894 list = &audit_inode_hash[h];
895 list_for_each_entry(e, list, list)
896 if (!audit_compare_rule(&entry->rule, &e->rule)) {
904 list_for_each_entry(e, list, list)
905 if (!audit_compare_rule(&entry->rule, &e->rule)) {
914 /* Get path information necessary for adding watches. */
915 static int audit_get_nd(char *path, struct nameidata **ndp,
916 struct nameidata **ndw)
918 struct nameidata *ndparent, *ndwatch;
921 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
922 if (unlikely(!ndparent))
925 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
926 if (unlikely(!ndwatch)) {
931 err = path_lookup(path, LOOKUP_PARENT, ndparent);
938 err = path_lookup(path, 0, ndwatch);
950 /* Release resources used for watch path information. */
951 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
963 /* Associate the given rule with an existing parent inotify_watch.
964 * Caller must hold audit_filter_mutex. */
965 static void audit_add_to_parent(struct audit_krule *krule,
966 struct audit_parent *parent)
968 struct audit_watch *w, *watch = krule->watch;
971 list_for_each_entry(w, &parent->watches, wlist) {
972 if (strcmp(watch->path, w->path))
977 /* put krule's and initial refs to temporary watch */
978 audit_put_watch(watch);
979 audit_put_watch(watch);
982 krule->watch = watch = w;
987 get_inotify_watch(&parent->wdata);
988 watch->parent = parent;
990 list_add(&watch->wlist, &parent->watches);
992 list_add(&krule->rlist, &watch->rules);
995 /* Find a matching watch entry, or add this one.
996 * Caller must hold audit_filter_mutex. */
997 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
998 struct nameidata *ndw)
1000 struct audit_watch *watch = krule->watch;
1001 struct inotify_watch *i_watch;
1002 struct audit_parent *parent;
1005 /* update watch filter fields */
1007 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
1008 watch->ino = ndw->dentry->d_inode->i_ino;
1011 /* The audit_filter_mutex must not be held during inotify calls because
1012 * we hold it during inotify event callback processing. If an existing
1013 * inotify watch is found, inotify_find_watch() grabs a reference before
1016 mutex_unlock(&audit_filter_mutex);
1018 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
1019 parent = audit_init_parent(ndp);
1020 if (IS_ERR(parent)) {
1021 /* caller expects mutex locked */
1022 mutex_lock(&audit_filter_mutex);
1023 return PTR_ERR(parent);
1026 parent = container_of(i_watch, struct audit_parent, wdata);
1028 mutex_lock(&audit_filter_mutex);
1030 /* parent was moved before we took audit_filter_mutex */
1031 if (parent->flags & AUDIT_PARENT_INVALID)
1034 audit_add_to_parent(krule, parent);
1036 /* match get in audit_init_parent or inotify_find_watch */
1037 put_inotify_watch(&parent->wdata);
1041 /* Add rule to given filterlist if not a duplicate. */
1042 static inline int audit_add_rule(struct audit_entry *entry,
1043 struct list_head *list)
1045 struct audit_entry *e;
1046 struct audit_field *inode_f = entry->rule.inode_f;
1047 struct audit_watch *watch = entry->rule.watch;
1048 struct nameidata *ndp, *ndw;
1049 int h, err, putnd_needed = 0;
1052 h = audit_hash_ino(inode_f->val);
1053 list = &audit_inode_hash[h];
1056 mutex_lock(&audit_filter_mutex);
1057 e = audit_find_rule(entry, list);
1058 mutex_unlock(&audit_filter_mutex);
1064 /* Avoid calling path_lookup under audit_filter_mutex. */
1066 err = audit_get_nd(watch->path, &ndp, &ndw);
1072 mutex_lock(&audit_filter_mutex);
1074 /* audit_filter_mutex is dropped and re-taken during this call */
1075 err = audit_add_watch(&entry->rule, ndp, ndw);
1077 mutex_unlock(&audit_filter_mutex);
1080 h = audit_hash_ino((u32)watch->ino);
1081 list = &audit_inode_hash[h];
1084 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1085 list_add_rcu(&entry->list, list);
1087 list_add_tail_rcu(&entry->list, list);
1089 mutex_unlock(&audit_filter_mutex);
1092 audit_put_nd(ndp, ndw);
1098 audit_put_nd(ndp, ndw);
1100 audit_put_watch(watch); /* tmp watch, matches initial get */
1104 /* Remove an existing rule from filterlist. */
1105 static inline int audit_del_rule(struct audit_entry *entry,
1106 struct list_head *list)
1108 struct audit_entry *e;
1109 struct audit_field *inode_f = entry->rule.inode_f;
1110 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1111 LIST_HEAD(inotify_list);
1115 h = audit_hash_ino(inode_f->val);
1116 list = &audit_inode_hash[h];
1119 mutex_lock(&audit_filter_mutex);
1120 e = audit_find_rule(entry, list);
1122 mutex_unlock(&audit_filter_mutex);
1127 watch = e->rule.watch;
1129 struct audit_parent *parent = watch->parent;
1131 list_del(&e->rule.rlist);
1133 if (list_empty(&watch->rules)) {
1134 audit_remove_watch(watch);
1136 if (list_empty(&parent->watches)) {
1137 /* Put parent on the inotify un-registration
1138 * list. Grab a reference before releasing
1139 * audit_filter_mutex, to be released in
1140 * audit_inotify_unregister(). */
1141 list_add(&parent->ilist, &inotify_list);
1142 get_inotify_watch(&parent->wdata);
1147 list_del_rcu(&e->list);
1148 call_rcu(&e->rcu, audit_free_rule_rcu);
1150 mutex_unlock(&audit_filter_mutex);
1152 if (!list_empty(&inotify_list))
1153 audit_inotify_unregister(&inotify_list);
1157 audit_put_watch(tmp_watch); /* match initial get */
1162 /* List rules using struct audit_rule. Exists for backward
1163 * compatibility with userspace. */
1164 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1166 struct sk_buff *skb;
1167 struct audit_entry *entry;
1170 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1171 * iterator to sync with list writers. */
1172 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1173 list_for_each_entry(entry, &audit_filter_list[i], list) {
1174 struct audit_rule *rule;
1176 rule = audit_krule_to_rule(&entry->rule);
1177 if (unlikely(!rule))
1179 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1180 rule, sizeof(*rule));
1182 skb_queue_tail(q, skb);
1186 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1187 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1188 struct audit_rule *rule;
1190 rule = audit_krule_to_rule(&entry->rule);
1191 if (unlikely(!rule))
1193 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1194 rule, sizeof(*rule));
1196 skb_queue_tail(q, skb);
1200 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1202 skb_queue_tail(q, skb);
1205 /* List rules using struct audit_rule_data. */
1206 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1208 struct sk_buff *skb;
1209 struct audit_entry *e;
1212 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1213 * iterator to sync with list writers. */
1214 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1215 list_for_each_entry(e, &audit_filter_list[i], list) {
1216 struct audit_rule_data *data;
1218 data = audit_krule_to_data(&e->rule);
1219 if (unlikely(!data))
1221 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1222 data, sizeof(*data) + data->buflen);
1224 skb_queue_tail(q, skb);
1228 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1229 list_for_each_entry(e, &audit_inode_hash[i], list) {
1230 struct audit_rule_data *data;
1232 data = audit_krule_to_data(&e->rule);
1233 if (unlikely(!data))
1235 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1236 data, sizeof(*data) + data->buflen);
1238 skb_queue_tail(q, skb);
1242 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1244 skb_queue_tail(q, skb);
1248 * audit_receive_filter - apply all rules to the specified message type
1249 * @type: audit message type
1250 * @pid: target pid for netlink audit messages
1251 * @uid: target uid for netlink audit messages
1252 * @seq: netlink audit message sequence (serial) number
1253 * @data: payload data
1254 * @datasz: size of payload data
1255 * @loginuid: loginuid of sender
1256 * @sid: SE Linux Security ID of sender
1258 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1259 size_t datasz, uid_t loginuid, u32 sid)
1261 struct task_struct *tsk;
1262 struct audit_netlink_list *dest;
1264 struct audit_entry *entry;
1268 case AUDIT_LIST_RULES:
1269 /* We can't just spew out the rules here because we might fill
1270 * the available socket buffer space and deadlock waiting for
1271 * auditctl to read from it... which isn't ever going to
1272 * happen if we're actually running in the context of auditctl
1273 * trying to _send_ the stuff */
1275 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1279 skb_queue_head_init(&dest->q);
1281 mutex_lock(&audit_filter_mutex);
1282 if (type == AUDIT_LIST)
1283 audit_list(pid, seq, &dest->q);
1285 audit_list_rules(pid, seq, &dest->q);
1286 mutex_unlock(&audit_filter_mutex);
1288 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1290 skb_queue_purge(&dest->q);
1296 case AUDIT_ADD_RULE:
1297 if (type == AUDIT_ADD)
1298 entry = audit_rule_to_entry(data);
1300 entry = audit_data_to_entry(data, datasz);
1302 return PTR_ERR(entry);
1304 err = audit_add_rule(entry,
1305 &audit_filter_list[entry->rule.listnr]);
1310 if (selinux_ctxid_to_string(sid, &ctx, &len)) {
1311 /* Maybe call audit_panic? */
1312 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1313 "auid=%u ssid=%u add rule to list=%d res=%d",
1314 loginuid, sid, entry->rule.listnr, !err);
1316 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1317 "auid=%u subj=%s add rule to list=%d res=%d",
1318 loginuid, ctx, entry->rule.listnr, !err);
1321 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1322 "auid=%u add rule to list=%d res=%d",
1323 loginuid, entry->rule.listnr, !err);
1326 audit_free_rule(entry);
1329 case AUDIT_DEL_RULE:
1330 if (type == AUDIT_DEL)
1331 entry = audit_rule_to_entry(data);
1333 entry = audit_data_to_entry(data, datasz);
1335 return PTR_ERR(entry);
1337 err = audit_del_rule(entry,
1338 &audit_filter_list[entry->rule.listnr]);
1343 if (selinux_ctxid_to_string(sid, &ctx, &len)) {
1344 /* Maybe call audit_panic? */
1345 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1346 "auid=%u ssid=%u remove rule from list=%d res=%d",
1347 loginuid, sid, entry->rule.listnr, !err);
1349 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1350 "auid=%u subj=%s remove rule from list=%d res=%d",
1351 loginuid, ctx, entry->rule.listnr, !err);
1354 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1355 "auid=%u remove rule from list=%d res=%d",
1356 loginuid, entry->rule.listnr, !err);
1358 audit_free_rule(entry);
1367 int audit_comparator(const u32 left, const u32 op, const u32 right)
1371 return (left == right);
1372 case AUDIT_NOT_EQUAL:
1373 return (left != right);
1374 case AUDIT_LESS_THAN:
1375 return (left < right);
1376 case AUDIT_LESS_THAN_OR_EQUAL:
1377 return (left <= right);
1378 case AUDIT_GREATER_THAN:
1379 return (left > right);
1380 case AUDIT_GREATER_THAN_OR_EQUAL:
1381 return (left >= right);
1387 /* Compare given dentry name with last component in given path,
1388 * return of 0 indicates a match. */
1389 int audit_compare_dname_path(const char *dname, const char *path)
1394 if (!dname || !path)
1397 dlen = strlen(dname);
1398 plen = strlen(path);
1402 /* disregard trailing slashes */
1403 p = path + plen - 1;
1404 while ((*p == '/') && (p > path))
1407 /* find last path component */
1411 else if (p > path) {
1418 return strncmp(p, dname, dlen);
1421 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1422 struct audit_krule *rule,
1423 enum audit_state *state)
1427 for (i = 0; i < rule->field_count; i++) {
1428 struct audit_field *f = &rule->fields[i];
1433 result = audit_comparator(cb->creds.pid, f->op, f->val);
1436 result = audit_comparator(cb->creds.uid, f->op, f->val);
1439 result = audit_comparator(cb->creds.gid, f->op, f->val);
1441 case AUDIT_LOGINUID:
1442 result = audit_comparator(cb->loginuid, f->op, f->val);
1449 switch (rule->action) {
1450 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1451 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1456 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1458 struct audit_entry *e;
1459 enum audit_state state;
1463 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1464 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1465 if (state == AUDIT_DISABLED)
1472 return ret; /* Audit by default */
1475 int audit_filter_type(int type)
1477 struct audit_entry *e;
1481 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1482 goto unlock_and_return;
1484 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1487 for (i = 0; i < e->rule.field_count; i++) {
1488 struct audit_field *f = &e->rule.fields[i];
1489 if (f->type == AUDIT_MSGTYPE) {
1490 result = audit_comparator(type, f->op, f->val);
1496 goto unlock_and_return;
1503 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1504 are selinux fields specified in the rule, 0 otherwise. */
1505 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1509 for (i = 0; i < rule->field_count; i++) {
1510 struct audit_field *f = &rule->fields[i];
1524 /* This function will re-initialize the se_rule field of all applicable rules.
1525 * It will traverse the filter lists serarching for rules that contain selinux
1526 * specific filter fields. When such a rule is found, it is copied, the
1527 * selinux field is re-initialized, and the old rule is replaced with the
1529 int selinux_audit_rule_update(void)
1531 struct audit_entry *entry, *n, *nentry;
1532 struct audit_watch *watch;
1535 /* audit_filter_mutex synchronizes the writers */
1536 mutex_lock(&audit_filter_mutex);
1538 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1539 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1540 if (!audit_rule_has_selinux(&entry->rule))
1543 watch = entry->rule.watch;
1544 nentry = audit_dupe_rule(&entry->rule, watch);
1545 if (unlikely(IS_ERR(nentry))) {
1546 /* save the first error encountered for the
1549 err = PTR_ERR(nentry);
1550 audit_panic("error updating selinux filters");
1552 list_del(&entry->rule.rlist);
1553 list_del_rcu(&entry->list);
1556 list_add(&nentry->rule.rlist,
1558 list_del(&entry->rule.rlist);
1560 list_replace_rcu(&entry->list, &nentry->list);
1562 call_rcu(&entry->rcu, audit_free_rule_rcu);
1566 mutex_unlock(&audit_filter_mutex);
1571 /* Update watch data in audit rules based on inotify events. */
1572 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1573 u32 cookie, const char *dname, struct inode *inode)
1575 struct audit_parent *parent;
1577 parent = container_of(i_watch, struct audit_parent, wdata);
1579 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1580 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1582 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1583 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1584 /* inotify automatically removes the watch and sends IN_IGNORED */
1585 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1586 audit_remove_parent_watches(parent);
1587 /* inotify does not remove the watch, so remove it manually */
1588 else if(mask & IN_MOVE_SELF) {
1589 audit_remove_parent_watches(parent);
1590 inotify_remove_watch_locked(audit_ih, i_watch);
1591 } else if (mask & IN_IGNORED)
1592 put_inotify_watch(i_watch);