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];
351 if (f->type & AUDIT_UNUSED_BITS)
363 err = audit_to_inode(&entry->rule, f);
369 entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1;
371 /* Support for legacy operators where
372 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
373 if (f->op & AUDIT_NEGATE)
374 f->op = AUDIT_NOT_EQUAL;
377 else if (f->op == AUDIT_OPERATORS) {
383 f = entry->rule.inode_f;
386 case AUDIT_NOT_EQUAL:
387 entry->rule.inode_f = NULL;
399 audit_free_rule(entry);
403 /* Translate struct audit_rule_data to kernel's rule respresentation. */
404 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
408 struct audit_entry *entry;
409 struct audit_field *f;
411 size_t remain = datasz - sizeof(struct audit_rule_data);
415 entry = audit_to_entry_common((struct audit_rule *)data);
420 entry->rule.vers_ops = 2;
421 for (i = 0; i < data->field_count; i++) {
422 struct audit_field *f = &entry->rule.fields[i];
425 if (!(data->fieldflags[i] & AUDIT_OPERATORS) ||
426 data->fieldflags[i] & ~AUDIT_OPERATORS)
429 f->op = data->fieldflags[i] & AUDIT_OPERATORS;
430 f->type = data->fields[i];
431 f->val = data->values[i];
440 str = audit_unpack_string(&bufp, &remain, f->val);
443 entry->rule.buflen += f->val;
445 err = selinux_audit_rule_init(f->type, f->op, str,
447 /* Keep currently invalid fields around in case they
448 * become valid after a policy reload. */
449 if (err == -EINVAL) {
450 printk(KERN_WARNING "audit rule for selinux "
451 "\'%s\' is invalid\n", str);
461 str = audit_unpack_string(&bufp, &remain, f->val);
464 entry->rule.buflen += f->val;
466 err = audit_to_watch(&entry->rule, str, f->val, f->op);
473 err = audit_to_inode(&entry->rule, f);
480 f = entry->rule.inode_f;
483 case AUDIT_NOT_EQUAL:
484 entry->rule.inode_f = NULL;
496 audit_free_rule(entry);
500 /* Pack a filter field's string representation into data block. */
501 static inline size_t audit_pack_string(void **bufp, char *str)
503 size_t len = strlen(str);
505 memcpy(*bufp, str, len);
511 /* Translate kernel rule respresentation to struct audit_rule.
512 * Exists for backward compatibility with userspace. */
513 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
515 struct audit_rule *rule;
518 rule = kmalloc(sizeof(*rule), GFP_KERNEL);
521 memset(rule, 0, sizeof(*rule));
523 rule->flags = krule->flags | krule->listnr;
524 rule->action = krule->action;
525 rule->field_count = krule->field_count;
526 for (i = 0; i < rule->field_count; i++) {
527 rule->values[i] = krule->fields[i].val;
528 rule->fields[i] = krule->fields[i].type;
530 if (krule->vers_ops == 1) {
531 if (krule->fields[i].op & AUDIT_NOT_EQUAL)
532 rule->fields[i] |= AUDIT_NEGATE;
534 rule->fields[i] |= krule->fields[i].op;
537 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
542 /* Translate kernel rule respresentation to struct audit_rule_data. */
543 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
545 struct audit_rule_data *data;
549 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
552 memset(data, 0, sizeof(*data));
554 data->flags = krule->flags | krule->listnr;
555 data->action = krule->action;
556 data->field_count = krule->field_count;
558 for (i = 0; i < data->field_count; i++) {
559 struct audit_field *f = &krule->fields[i];
561 data->fields[i] = f->type;
562 data->fieldflags[i] = f->op;
569 data->buflen += data->values[i] =
570 audit_pack_string(&bufp, f->se_str);
573 data->buflen += data->values[i] =
574 audit_pack_string(&bufp, krule->watch->path);
577 data->values[i] = f->val;
580 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
585 /* Compare two rules in kernel format. Considered success if rules
587 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
591 if (a->flags != b->flags ||
592 a->listnr != b->listnr ||
593 a->action != b->action ||
594 a->field_count != b->field_count)
597 for (i = 0; i < a->field_count; i++) {
598 if (a->fields[i].type != b->fields[i].type ||
599 a->fields[i].op != b->fields[i].op)
602 switch(a->fields[i].type) {
608 if (strcmp(a->fields[i].se_str, b->fields[i].se_str))
612 if (strcmp(a->watch->path, b->watch->path))
616 if (a->fields[i].val != b->fields[i].val)
621 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
622 if (a->mask[i] != b->mask[i])
628 /* Duplicate the given audit watch. The new watch's rules list is initialized
629 * to an empty list and wlist is undefined. */
630 static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
633 struct audit_watch *new;
635 path = kstrdup(old->path, GFP_KERNEL);
637 return ERR_PTR(-ENOMEM);
639 new = audit_init_watch(path);
640 if (unlikely(IS_ERR(new))) {
647 get_inotify_watch(&old->parent->wdata);
648 new->parent = old->parent;
654 /* Duplicate selinux field information. The se_rule is opaque, so must be
656 static inline int audit_dupe_selinux_field(struct audit_field *df,
657 struct audit_field *sf)
662 /* our own copy of se_str */
663 se_str = kstrdup(sf->se_str, GFP_KERNEL);
664 if (unlikely(IS_ERR(se_str)))
668 /* our own (refreshed) copy of se_rule */
669 ret = selinux_audit_rule_init(df->type, df->op, df->se_str,
671 /* Keep currently invalid fields around in case they
672 * become valid after a policy reload. */
673 if (ret == -EINVAL) {
674 printk(KERN_WARNING "audit rule for selinux \'%s\' is "
675 "invalid\n", df->se_str);
682 /* Duplicate an audit rule. This will be a deep copy with the exception
683 * of the watch - that pointer is carried over. The selinux specific fields
684 * will be updated in the copy. The point is to be able to replace the old
685 * rule with the new rule in the filterlist, then free the old rule.
686 * The rlist element is undefined; list manipulations are handled apart from
687 * the initial copy. */
688 static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
689 struct audit_watch *watch)
691 u32 fcount = old->field_count;
692 struct audit_entry *entry;
693 struct audit_krule *new;
696 entry = audit_init_entry(fcount);
697 if (unlikely(!entry))
698 return ERR_PTR(-ENOMEM);
701 new->vers_ops = old->vers_ops;
702 new->flags = old->flags;
703 new->listnr = old->listnr;
704 new->action = old->action;
705 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
706 new->mask[i] = old->mask[i];
707 new->buflen = old->buflen;
708 new->inode_f = old->inode_f;
710 new->field_count = old->field_count;
711 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
713 /* deep copy this information, updating the se_rule fields, because
714 * the originals will all be freed when the old rule is freed. */
715 for (i = 0; i < fcount; i++) {
716 switch (new->fields[i].type) {
722 err = audit_dupe_selinux_field(&new->fields[i],
726 audit_free_rule(entry);
732 audit_get_watch(watch);
739 /* Update inode info in audit rules based on filesystem event. */
740 static void audit_update_watch(struct audit_parent *parent,
741 const char *dname, dev_t dev,
742 unsigned long ino, unsigned invalidating)
744 struct audit_watch *owatch, *nwatch, *nextw;
745 struct audit_krule *r, *nextr;
746 struct audit_entry *oentry, *nentry;
747 struct audit_buffer *ab;
749 mutex_lock(&audit_filter_mutex);
750 list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
751 if (audit_compare_dname_path(dname, owatch->path))
754 /* If the update involves invalidating rules, do the inode-based
755 * filtering now, so we don't omit records. */
757 audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT)
758 audit_set_auditable(current->audit_context);
760 nwatch = audit_dupe_watch(owatch);
761 if (unlikely(IS_ERR(nwatch))) {
762 mutex_unlock(&audit_filter_mutex);
763 audit_panic("error updating watch, skipping");
769 list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
771 oentry = container_of(r, struct audit_entry, rule);
772 list_del(&oentry->rule.rlist);
773 list_del_rcu(&oentry->list);
775 nentry = audit_dupe_rule(&oentry->rule, nwatch);
776 if (unlikely(IS_ERR(nentry)))
777 audit_panic("error updating watch, removing");
779 int h = audit_hash_ino((u32)ino);
780 list_add(&nentry->rule.rlist, &nwatch->rules);
781 list_add_rcu(&nentry->list, &audit_inode_hash[h]);
784 call_rcu(&oentry->rcu, audit_free_rule_rcu);
787 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
788 audit_log_format(ab, "audit updated rules specifying watch=");
789 audit_log_untrustedstring(ab, owatch->path);
790 audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino);
793 audit_remove_watch(owatch);
794 goto add_watch_to_parent; /* event applies to a single watch */
796 mutex_unlock(&audit_filter_mutex);
800 list_add(&nwatch->wlist, &parent->watches);
801 mutex_unlock(&audit_filter_mutex);
805 /* Remove all watches & rules associated with a parent that is going away. */
806 static void audit_remove_parent_watches(struct audit_parent *parent)
808 struct audit_watch *w, *nextw;
809 struct audit_krule *r, *nextr;
810 struct audit_entry *e;
812 mutex_lock(&audit_filter_mutex);
813 parent->flags |= AUDIT_PARENT_INVALID;
814 list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
815 list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
816 e = container_of(r, struct audit_entry, rule);
818 list_del_rcu(&e->list);
819 call_rcu(&e->rcu, audit_free_rule_rcu);
821 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
822 "audit implicitly removed rule from list=%d\n",
825 audit_remove_watch(w);
827 mutex_unlock(&audit_filter_mutex);
830 /* Unregister inotify watches for parents on in_list.
831 * Generates an IN_IGNORED event. */
832 static void audit_inotify_unregister(struct list_head *in_list)
834 struct audit_parent *p, *n;
836 list_for_each_entry_safe(p, n, in_list, ilist) {
838 inotify_rm_watch(audit_ih, &p->wdata);
839 /* the put matching the get in audit_do_del_rule() */
840 put_inotify_watch(&p->wdata);
844 /* Find an existing audit rule.
845 * Caller must hold audit_filter_mutex to prevent stale rule data. */
846 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
847 struct list_head *list)
849 struct audit_entry *e, *found = NULL;
852 if (entry->rule.watch) {
853 /* we don't know the inode number, so must walk entire hash */
854 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
855 list = &audit_inode_hash[h];
856 list_for_each_entry(e, list, list)
857 if (!audit_compare_rule(&entry->rule, &e->rule)) {
865 list_for_each_entry(e, list, list)
866 if (!audit_compare_rule(&entry->rule, &e->rule)) {
875 /* Get path information necessary for adding watches. */
876 static int audit_get_nd(char *path, struct nameidata **ndp,
877 struct nameidata **ndw)
879 struct nameidata *ndparent, *ndwatch;
882 ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
883 if (unlikely(!ndparent))
886 ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
887 if (unlikely(!ndwatch)) {
892 err = path_lookup(path, LOOKUP_PARENT, ndparent);
899 err = path_lookup(path, 0, ndwatch);
911 /* Release resources used for watch path information. */
912 static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
924 /* Associate the given rule with an existing parent inotify_watch.
925 * Caller must hold audit_filter_mutex. */
926 static void audit_add_to_parent(struct audit_krule *krule,
927 struct audit_parent *parent)
929 struct audit_watch *w, *watch = krule->watch;
932 list_for_each_entry(w, &parent->watches, wlist) {
933 if (strcmp(watch->path, w->path))
938 /* put krule's and initial refs to temporary watch */
939 audit_put_watch(watch);
940 audit_put_watch(watch);
943 krule->watch = watch = w;
948 get_inotify_watch(&parent->wdata);
949 watch->parent = parent;
951 list_add(&watch->wlist, &parent->watches);
953 list_add(&krule->rlist, &watch->rules);
956 /* Find a matching watch entry, or add this one.
957 * Caller must hold audit_filter_mutex. */
958 static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
959 struct nameidata *ndw)
961 struct audit_watch *watch = krule->watch;
962 struct inotify_watch *i_watch;
963 struct audit_parent *parent;
966 /* update watch filter fields */
968 watch->dev = ndw->dentry->d_inode->i_sb->s_dev;
969 watch->ino = ndw->dentry->d_inode->i_ino;
972 /* The audit_filter_mutex must not be held during inotify calls because
973 * we hold it during inotify event callback processing. If an existing
974 * inotify watch is found, inotify_find_watch() grabs a reference before
977 mutex_unlock(&audit_filter_mutex);
979 if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) {
980 parent = audit_init_parent(ndp);
981 if (IS_ERR(parent)) {
982 /* caller expects mutex locked */
983 mutex_lock(&audit_filter_mutex);
984 return PTR_ERR(parent);
987 parent = container_of(i_watch, struct audit_parent, wdata);
989 mutex_lock(&audit_filter_mutex);
991 /* parent was moved before we took audit_filter_mutex */
992 if (parent->flags & AUDIT_PARENT_INVALID)
995 audit_add_to_parent(krule, parent);
997 /* match get in audit_init_parent or inotify_find_watch */
998 put_inotify_watch(&parent->wdata);
1002 /* Add rule to given filterlist if not a duplicate. */
1003 static inline int audit_add_rule(struct audit_entry *entry,
1004 struct list_head *list)
1006 struct audit_entry *e;
1007 struct audit_field *inode_f = entry->rule.inode_f;
1008 struct audit_watch *watch = entry->rule.watch;
1009 struct nameidata *ndp, *ndw;
1010 int h, err, putnd_needed = 0;
1013 h = audit_hash_ino(inode_f->val);
1014 list = &audit_inode_hash[h];
1017 mutex_lock(&audit_filter_mutex);
1018 e = audit_find_rule(entry, list);
1019 mutex_unlock(&audit_filter_mutex);
1025 /* Avoid calling path_lookup under audit_filter_mutex. */
1027 err = audit_get_nd(watch->path, &ndp, &ndw);
1033 mutex_lock(&audit_filter_mutex);
1035 /* audit_filter_mutex is dropped and re-taken during this call */
1036 err = audit_add_watch(&entry->rule, ndp, ndw);
1038 mutex_unlock(&audit_filter_mutex);
1041 h = audit_hash_ino((u32)watch->ino);
1042 list = &audit_inode_hash[h];
1045 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1046 list_add_rcu(&entry->list, list);
1048 list_add_tail_rcu(&entry->list, list);
1050 mutex_unlock(&audit_filter_mutex);
1053 audit_put_nd(ndp, ndw);
1059 audit_put_nd(ndp, ndw);
1061 audit_put_watch(watch); /* tmp watch, matches initial get */
1065 /* Remove an existing rule from filterlist. */
1066 static inline int audit_del_rule(struct audit_entry *entry,
1067 struct list_head *list)
1069 struct audit_entry *e;
1070 struct audit_field *inode_f = entry->rule.inode_f;
1071 struct audit_watch *watch, *tmp_watch = entry->rule.watch;
1072 LIST_HEAD(inotify_list);
1076 h = audit_hash_ino(inode_f->val);
1077 list = &audit_inode_hash[h];
1080 mutex_lock(&audit_filter_mutex);
1081 e = audit_find_rule(entry, list);
1083 mutex_unlock(&audit_filter_mutex);
1088 watch = e->rule.watch;
1090 struct audit_parent *parent = watch->parent;
1092 list_del(&e->rule.rlist);
1094 if (list_empty(&watch->rules)) {
1095 audit_remove_watch(watch);
1097 if (list_empty(&parent->watches)) {
1098 /* Put parent on the inotify un-registration
1099 * list. Grab a reference before releasing
1100 * audit_filter_mutex, to be released in
1101 * audit_inotify_unregister(). */
1102 list_add(&parent->ilist, &inotify_list);
1103 get_inotify_watch(&parent->wdata);
1108 list_del_rcu(&e->list);
1109 call_rcu(&e->rcu, audit_free_rule_rcu);
1111 mutex_unlock(&audit_filter_mutex);
1113 if (!list_empty(&inotify_list))
1114 audit_inotify_unregister(&inotify_list);
1118 audit_put_watch(tmp_watch); /* match initial get */
1123 /* List rules using struct audit_rule. Exists for backward
1124 * compatibility with userspace. */
1125 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1127 struct sk_buff *skb;
1128 struct audit_entry *entry;
1131 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1132 * iterator to sync with list writers. */
1133 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1134 list_for_each_entry(entry, &audit_filter_list[i], list) {
1135 struct audit_rule *rule;
1137 rule = audit_krule_to_rule(&entry->rule);
1138 if (unlikely(!rule))
1140 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1141 rule, sizeof(*rule));
1143 skb_queue_tail(q, skb);
1147 for (i = 0; i < AUDIT_INODE_BUCKETS; i++) {
1148 list_for_each_entry(entry, &audit_inode_hash[i], list) {
1149 struct audit_rule *rule;
1151 rule = audit_krule_to_rule(&entry->rule);
1152 if (unlikely(!rule))
1154 skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1155 rule, sizeof(*rule));
1157 skb_queue_tail(q, skb);
1161 skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1163 skb_queue_tail(q, skb);
1166 /* List rules using struct audit_rule_data. */
1167 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1169 struct sk_buff *skb;
1170 struct audit_entry *e;
1173 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1174 * iterator to sync with list writers. */
1175 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1176 list_for_each_entry(e, &audit_filter_list[i], list) {
1177 struct audit_rule_data *data;
1179 data = audit_krule_to_data(&e->rule);
1180 if (unlikely(!data))
1182 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1183 data, sizeof(*data) + data->buflen);
1185 skb_queue_tail(q, skb);
1189 for (i=0; i< AUDIT_INODE_BUCKETS; i++) {
1190 list_for_each_entry(e, &audit_inode_hash[i], list) {
1191 struct audit_rule_data *data;
1193 data = audit_krule_to_data(&e->rule);
1194 if (unlikely(!data))
1196 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1197 data, sizeof(*data) + data->buflen);
1199 skb_queue_tail(q, skb);
1203 skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1205 skb_queue_tail(q, skb);
1209 * audit_receive_filter - apply all rules to the specified message type
1210 * @type: audit message type
1211 * @pid: target pid for netlink audit messages
1212 * @uid: target uid for netlink audit messages
1213 * @seq: netlink audit message sequence (serial) number
1214 * @data: payload data
1215 * @datasz: size of payload data
1216 * @loginuid: loginuid of sender
1217 * @sid: SE Linux Security ID of sender
1219 int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
1220 size_t datasz, uid_t loginuid, u32 sid)
1222 struct task_struct *tsk;
1223 struct audit_netlink_list *dest;
1225 struct audit_entry *entry;
1229 case AUDIT_LIST_RULES:
1230 /* We can't just spew out the rules here because we might fill
1231 * the available socket buffer space and deadlock waiting for
1232 * auditctl to read from it... which isn't ever going to
1233 * happen if we're actually running in the context of auditctl
1234 * trying to _send_ the stuff */
1236 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1240 skb_queue_head_init(&dest->q);
1242 mutex_lock(&audit_filter_mutex);
1243 if (type == AUDIT_LIST)
1244 audit_list(pid, seq, &dest->q);
1246 audit_list_rules(pid, seq, &dest->q);
1247 mutex_unlock(&audit_filter_mutex);
1249 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1251 skb_queue_purge(&dest->q);
1257 case AUDIT_ADD_RULE:
1258 if (type == AUDIT_ADD)
1259 entry = audit_rule_to_entry(data);
1261 entry = audit_data_to_entry(data, datasz);
1263 return PTR_ERR(entry);
1265 err = audit_add_rule(entry,
1266 &audit_filter_list[entry->rule.listnr]);
1271 if (selinux_ctxid_to_string(sid, &ctx, &len)) {
1272 /* Maybe call audit_panic? */
1273 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1274 "auid=%u ssid=%u add rule to list=%d res=%d",
1275 loginuid, sid, entry->rule.listnr, !err);
1277 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1278 "auid=%u subj=%s add rule to list=%d res=%d",
1279 loginuid, ctx, entry->rule.listnr, !err);
1282 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1283 "auid=%u add rule to list=%d res=%d",
1284 loginuid, entry->rule.listnr, !err);
1287 audit_free_rule(entry);
1290 case AUDIT_DEL_RULE:
1291 if (type == AUDIT_DEL)
1292 entry = audit_rule_to_entry(data);
1294 entry = audit_data_to_entry(data, datasz);
1296 return PTR_ERR(entry);
1298 err = audit_del_rule(entry,
1299 &audit_filter_list[entry->rule.listnr]);
1304 if (selinux_ctxid_to_string(sid, &ctx, &len)) {
1305 /* Maybe call audit_panic? */
1306 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1307 "auid=%u ssid=%u remove rule from list=%d res=%d",
1308 loginuid, sid, entry->rule.listnr, !err);
1310 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1311 "auid=%u subj=%s remove rule from list=%d res=%d",
1312 loginuid, ctx, entry->rule.listnr, !err);
1315 audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
1316 "auid=%u remove rule from list=%d res=%d",
1317 loginuid, entry->rule.listnr, !err);
1319 audit_free_rule(entry);
1328 int audit_comparator(const u32 left, const u32 op, const u32 right)
1332 return (left == right);
1333 case AUDIT_NOT_EQUAL:
1334 return (left != right);
1335 case AUDIT_LESS_THAN:
1336 return (left < right);
1337 case AUDIT_LESS_THAN_OR_EQUAL:
1338 return (left <= right);
1339 case AUDIT_GREATER_THAN:
1340 return (left > right);
1341 case AUDIT_GREATER_THAN_OR_EQUAL:
1342 return (left >= right);
1348 /* Compare given dentry name with last component in given path,
1349 * return of 0 indicates a match. */
1350 int audit_compare_dname_path(const char *dname, const char *path)
1355 if (!dname || !path)
1358 dlen = strlen(dname);
1359 plen = strlen(path);
1363 /* disregard trailing slashes */
1364 p = path + plen - 1;
1365 while ((*p == '/') && (p > path))
1368 /* find last path component */
1372 else if (p > path) {
1379 return strncmp(p, dname, dlen);
1382 static int audit_filter_user_rules(struct netlink_skb_parms *cb,
1383 struct audit_krule *rule,
1384 enum audit_state *state)
1388 for (i = 0; i < rule->field_count; i++) {
1389 struct audit_field *f = &rule->fields[i];
1394 result = audit_comparator(cb->creds.pid, f->op, f->val);
1397 result = audit_comparator(cb->creds.uid, f->op, f->val);
1400 result = audit_comparator(cb->creds.gid, f->op, f->val);
1402 case AUDIT_LOGINUID:
1403 result = audit_comparator(cb->loginuid, f->op, f->val);
1410 switch (rule->action) {
1411 case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
1412 case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
1417 int audit_filter_user(struct netlink_skb_parms *cb, int type)
1419 struct audit_entry *e;
1420 enum audit_state state;
1424 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1425 if (audit_filter_user_rules(cb, &e->rule, &state)) {
1426 if (state == AUDIT_DISABLED)
1433 return ret; /* Audit by default */
1436 int audit_filter_type(int type)
1438 struct audit_entry *e;
1442 if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1443 goto unlock_and_return;
1445 list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1448 for (i = 0; i < e->rule.field_count; i++) {
1449 struct audit_field *f = &e->rule.fields[i];
1450 if (f->type == AUDIT_MSGTYPE) {
1451 result = audit_comparator(type, f->op, f->val);
1457 goto unlock_and_return;
1464 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1465 are selinux fields specified in the rule, 0 otherwise. */
1466 static inline int audit_rule_has_selinux(struct audit_krule *rule)
1470 for (i = 0; i < rule->field_count; i++) {
1471 struct audit_field *f = &rule->fields[i];
1485 /* This function will re-initialize the se_rule field of all applicable rules.
1486 * It will traverse the filter lists serarching for rules that contain selinux
1487 * specific filter fields. When such a rule is found, it is copied, the
1488 * selinux field is re-initialized, and the old rule is replaced with the
1490 int selinux_audit_rule_update(void)
1492 struct audit_entry *entry, *n, *nentry;
1493 struct audit_watch *watch;
1496 /* audit_filter_mutex synchronizes the writers */
1497 mutex_lock(&audit_filter_mutex);
1499 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1500 list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) {
1501 if (!audit_rule_has_selinux(&entry->rule))
1504 watch = entry->rule.watch;
1505 nentry = audit_dupe_rule(&entry->rule, watch);
1506 if (unlikely(IS_ERR(nentry))) {
1507 /* save the first error encountered for the
1510 err = PTR_ERR(nentry);
1511 audit_panic("error updating selinux filters");
1513 list_del(&entry->rule.rlist);
1514 list_del_rcu(&entry->list);
1517 list_add(&nentry->rule.rlist,
1519 list_del(&entry->rule.rlist);
1521 list_replace_rcu(&entry->list, &nentry->list);
1523 call_rcu(&entry->rcu, audit_free_rule_rcu);
1527 mutex_unlock(&audit_filter_mutex);
1532 /* Update watch data in audit rules based on inotify events. */
1533 void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
1534 u32 cookie, const char *dname, struct inode *inode)
1536 struct audit_parent *parent;
1538 parent = container_of(i_watch, struct audit_parent, wdata);
1540 if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
1541 audit_update_watch(parent, dname, inode->i_sb->s_dev,
1543 else if (mask & (IN_DELETE|IN_MOVED_FROM))
1544 audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
1545 /* inotify automatically removes the watch and sends IN_IGNORED */
1546 else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
1547 audit_remove_parent_watches(parent);
1548 /* inotify does not remove the watch, so remove it manually */
1549 else if(mask & IN_MOVE_SELF) {
1550 audit_remove_parent_watches(parent);
1551 inotify_remove_watch_locked(audit_ih, i_watch);
1552 } else if (mask & IN_IGNORED)
1553 put_inotify_watch(i_watch);