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-rw-r--r--kernel/auditfilter.c481
1 files changed, 14 insertions, 467 deletions
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index e7466dd145c..9d4c93437de 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -27,7 +27,6 @@
#include <linux/namei.h>
#include <linux/netlink.h>
#include <linux/sched.h>
-#include <linux/inotify.h>
#include <linux/security.h>
#include "audit.h"
@@ -44,36 +43,6 @@
* be written directly provided audit_filter_mutex is held.
*/
-/*
- * Reference counting:
- *
- * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
- * event. Each audit_watch holds a reference to its associated parent.
- *
- * audit_watch: if added to lists, lifetime is from audit_init_watch() to
- * audit_remove_watch(). Additionally, an audit_watch may exist
- * temporarily to assist in searching existing filter data. Each
- * audit_krule holds a reference to its associated watch.
- */
-
-struct audit_parent {
- struct list_head ilist; /* entry in inotify registration list */
- struct list_head watches; /* associated watches */
- struct inotify_watch wdata; /* inotify watch data */
- unsigned flags; /* status flags */
-};
-
-/*
- * audit_parent status flags:
- *
- * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
- * a filesystem event to ensure we're adding audit watches to a valid parent.
- * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
- * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
- * we can receive while holding nameidata.
- */
-#define AUDIT_PARENT_INVALID 0x001
-
/* Audit filter lists, defined in <linux/audit.h> */
struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
LIST_HEAD_INIT(audit_filter_list[0]),
@@ -97,41 +66,6 @@ static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
DEFINE_MUTEX(audit_filter_mutex);
-/* Inotify events we care about. */
-#define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
-
-void audit_free_parent(struct inotify_watch *i_watch)
-{
- struct audit_parent *parent;
-
- parent = container_of(i_watch, struct audit_parent, wdata);
- WARN_ON(!list_empty(&parent->watches));
- kfree(parent);
-}
-
-static inline void audit_get_watch(struct audit_watch *watch)
-{
- atomic_inc(&watch->count);
-}
-
-static void audit_put_watch(struct audit_watch *watch)
-{
- if (atomic_dec_and_test(&watch->count)) {
- WARN_ON(watch->parent);
- WARN_ON(!list_empty(&watch->rules));
- kfree(watch->path);
- kfree(watch);
- }
-}
-
-static void audit_remove_watch(struct audit_watch *watch)
-{
- list_del(&watch->wlist);
- put_inotify_watch(&watch->parent->wdata);
- watch->parent = NULL;
- audit_put_watch(watch); /* match initial get */
-}
-
static inline void audit_free_rule(struct audit_entry *e)
{
int i;
@@ -156,50 +90,6 @@ void audit_free_rule_rcu(struct rcu_head *head)
audit_free_rule(e);
}
-/* Initialize a parent watch entry. */
-static struct audit_parent *audit_init_parent(struct nameidata *ndp)
-{
- struct audit_parent *parent;
- s32 wd;
-
- parent = kzalloc(sizeof(*parent), GFP_KERNEL);
- if (unlikely(!parent))
- return ERR_PTR(-ENOMEM);
-
- INIT_LIST_HEAD(&parent->watches);
- parent->flags = 0;
-
- inotify_init_watch(&parent->wdata);
- /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
- get_inotify_watch(&parent->wdata);
- wd = inotify_add_watch(audit_ih, &parent->wdata,
- ndp->path.dentry->d_inode, AUDIT_IN_WATCH);
- if (wd < 0) {
- audit_free_parent(&parent->wdata);
- return ERR_PTR(wd);
- }
-
- return parent;
-}
-
-/* Initialize a watch entry. */
-static struct audit_watch *audit_init_watch(char *path)
-{
- struct audit_watch *watch;
-
- watch = kzalloc(sizeof(*watch), GFP_KERNEL);
- if (unlikely(!watch))
- return ERR_PTR(-ENOMEM);
-
- INIT_LIST_HEAD(&watch->rules);
- atomic_set(&watch->count, 1);
- watch->path = path;
- watch->dev = (dev_t)-1;
- watch->ino = (unsigned long)-1;
-
- return watch;
-}
-
/* Initialize an audit filterlist entry. */
static inline struct audit_entry *audit_init_entry(u32 field_count)
{
@@ -260,31 +150,6 @@ static inline int audit_to_inode(struct audit_krule *krule,
return 0;
}
-/* Translate a watch string to kernel respresentation. */
-static int audit_to_watch(struct audit_krule *krule, char *path, int len,
- u32 op)
-{
- struct audit_watch *watch;
-
- if (!audit_ih)
- return -EOPNOTSUPP;
-
- if (path[0] != '/' || path[len-1] == '/' ||
- krule->listnr != AUDIT_FILTER_EXIT ||
- op != Audit_equal ||
- krule->inode_f || krule->watch || krule->tree)
- return -EINVAL;
-
- watch = audit_init_watch(path);
- if (IS_ERR(watch))
- return PTR_ERR(watch);
-
- audit_get_watch(watch);
- krule->watch = watch;
-
- return 0;
-}
-
static __u32 *classes[AUDIT_SYSCALL_CLASSES];
int __init audit_register_class(int class, unsigned *list)
@@ -766,7 +631,8 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
break;
case AUDIT_WATCH:
data->buflen += data->values[i] =
- audit_pack_string(&bufp, krule->watch->path);
+ audit_pack_string(&bufp,
+ audit_watch_path(krule->watch));
break;
case AUDIT_DIR:
data->buflen += data->values[i] =
@@ -818,7 +684,8 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
return 1;
break;
case AUDIT_WATCH:
- if (strcmp(a->watch->path, b->watch->path))
+ if (strcmp(audit_watch_path(a->watch),
+ audit_watch_path(b->watch)))
return 1;
break;
case AUDIT_DIR:
@@ -844,32 +711,6 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
return 0;
}
-/* Duplicate the given audit watch. The new watch's rules list is initialized
- * to an empty list and wlist is undefined. */
-static struct audit_watch *audit_dupe_watch(struct audit_watch *old)
-{
- char *path;
- struct audit_watch *new;
-
- path = kstrdup(old->path, GFP_KERNEL);
- if (unlikely(!path))
- return ERR_PTR(-ENOMEM);
-
- new = audit_init_watch(path);
- if (IS_ERR(new)) {
- kfree(path);
- goto out;
- }
-
- new->dev = old->dev;
- new->ino = old->ino;
- get_inotify_watch(&old->parent->wdata);
- new->parent = old->parent;
-
-out:
- return new;
-}
-
/* Duplicate LSM field information. The lsm_rule is opaque, so must be
* re-initialized. */
static inline int audit_dupe_lsm_field(struct audit_field *df,
@@ -904,8 +745,8 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
* rule with the new rule in the filterlist, then free the old rule.
* The rlist element is undefined; list manipulations are handled apart from
* the initial copy. */
-static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
- struct audit_watch *watch)
+struct audit_entry *audit_dupe_rule(struct audit_krule *old,
+ struct audit_watch *watch)
{
u32 fcount = old->field_count;
struct audit_entry *entry;
@@ -977,127 +818,6 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old,
return entry;
}
-static void audit_watch_log_rule_change(struct audit_krule *r, struct audit_watch *w, char *op)
-{
- if (audit_enabled) {
- struct audit_buffer *ab;
- ab = audit_log_start(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
- audit_log_format(ab, "auid=%u ses=%u op=",
- audit_get_loginuid(current),
- audit_get_sessionid(current));
- audit_log_string(ab, op);
- audit_log_format(ab, " path=");
- audit_log_untrustedstring(ab, w->path);
- if (r->filterkey) {
- audit_log_format(ab, " key=");
- audit_log_untrustedstring(ab, r->filterkey);
- } else
- audit_log_format(ab, " key=(null)");
- audit_log_format(ab, " list=%d res=1", r->listnr);
- audit_log_end(ab);
- }
-}
-
-/* Update inode info in audit rules based on filesystem event. */
-static void audit_update_watch(struct audit_parent *parent,
- const char *dname, dev_t dev,
- unsigned long ino, unsigned invalidating)
-{
- struct audit_watch *owatch, *nwatch, *nextw;
- struct audit_krule *r, *nextr;
- struct audit_entry *oentry, *nentry;
-
- mutex_lock(&audit_filter_mutex);
- list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) {
- if (audit_compare_dname_path(dname, owatch->path, NULL))
- continue;
-
- /* If the update involves invalidating rules, do the inode-based
- * filtering now, so we don't omit records. */
- if (invalidating && current->audit_context)
- audit_filter_inodes(current, current->audit_context);
-
- nwatch = audit_dupe_watch(owatch);
- if (IS_ERR(nwatch)) {
- mutex_unlock(&audit_filter_mutex);
- audit_panic("error updating watch, skipping");
- return;
- }
- nwatch->dev = dev;
- nwatch->ino = ino;
-
- list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) {
-
- oentry = container_of(r, struct audit_entry, rule);
- list_del(&oentry->rule.rlist);
- list_del_rcu(&oentry->list);
-
- nentry = audit_dupe_rule(&oentry->rule, nwatch);
- if (IS_ERR(nentry)) {
- list_del(&oentry->rule.list);
- audit_panic("error updating watch, removing");
- } else {
- int h = audit_hash_ino((u32)ino);
- list_add(&nentry->rule.rlist, &nwatch->rules);
- list_add_rcu(&nentry->list, &audit_inode_hash[h]);
- list_replace(&oentry->rule.list,
- &nentry->rule.list);
- }
-
- audit_watch_log_rule_change(r, owatch, "updated rules");
-
- call_rcu(&oentry->rcu, audit_free_rule_rcu);
- }
-
- audit_remove_watch(owatch);
- goto add_watch_to_parent; /* event applies to a single watch */
- }
- mutex_unlock(&audit_filter_mutex);
- return;
-
-add_watch_to_parent:
- list_add(&nwatch->wlist, &parent->watches);
- mutex_unlock(&audit_filter_mutex);
- return;
-}
-
-/* Remove all watches & rules associated with a parent that is going away. */
-static void audit_remove_parent_watches(struct audit_parent *parent)
-{
- struct audit_watch *w, *nextw;
- struct audit_krule *r, *nextr;
- struct audit_entry *e;
-
- mutex_lock(&audit_filter_mutex);
- parent->flags |= AUDIT_PARENT_INVALID;
- list_for_each_entry_safe(w, nextw, &parent->watches, wlist) {
- list_for_each_entry_safe(r, nextr, &w->rules, rlist) {
- e = container_of(r, struct audit_entry, rule);
- audit_watch_log_rule_change(r, w, "remove rule");
- list_del(&r->rlist);
- list_del(&r->list);
- list_del_rcu(&e->list);
- call_rcu(&e->rcu, audit_free_rule_rcu);
- }
- audit_remove_watch(w);
- }
- mutex_unlock(&audit_filter_mutex);
-}
-
-/* Unregister inotify watches for parents on in_list.
- * Generates an IN_IGNORED event. */
-static void audit_inotify_unregister(struct list_head *in_list)
-{
- struct audit_parent *p, *n;
-
- list_for_each_entry_safe(p, n, in_list, ilist) {
- list_del(&p->ilist);
- inotify_rm_watch(audit_ih, &p->wdata);
- /* the unpin matching the pin in audit_do_del_rule() */
- unpin_inotify_watch(&p->wdata);
- }
-}
-
/* Find an existing audit rule.
* Caller must hold audit_filter_mutex to prevent stale rule data. */
static struct audit_entry *audit_find_rule(struct audit_entry *entry,
@@ -1135,134 +855,6 @@ out:
return found;
}
-/* Get path information necessary for adding watches. */
-static int audit_get_nd(char *path, struct nameidata **ndp,
- struct nameidata **ndw)
-{
- struct nameidata *ndparent, *ndwatch;
- int err;
-
- ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL);
- if (unlikely(!ndparent))
- return -ENOMEM;
-
- ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL);
- if (unlikely(!ndwatch)) {
- kfree(ndparent);
- return -ENOMEM;
- }
-
- err = path_lookup(path, LOOKUP_PARENT, ndparent);
- if (err) {
- kfree(ndparent);
- kfree(ndwatch);
- return err;
- }
-
- err = path_lookup(path, 0, ndwatch);
- if (err) {
- kfree(ndwatch);
- ndwatch = NULL;
- }
-
- *ndp = ndparent;
- *ndw = ndwatch;
-
- return 0;
-}
-
-/* Release resources used for watch path information. */
-static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw)
-{
- if (ndp) {
- path_put(&ndp->path);
- kfree(ndp);
- }
- if (ndw) {
- path_put(&ndw->path);
- kfree(ndw);
- }
-}
-
-/* Associate the given rule with an existing parent inotify_watch.
- * Caller must hold audit_filter_mutex. */
-static void audit_add_to_parent(struct audit_krule *krule,
- struct audit_parent *parent)
-{
- struct audit_watch *w, *watch = krule->watch;
- int watch_found = 0;
-
- list_for_each_entry(w, &parent->watches, wlist) {
- if (strcmp(watch->path, w->path))
- continue;
-
- watch_found = 1;
-
- /* put krule's and initial refs to temporary watch */
- audit_put_watch(watch);
- audit_put_watch(watch);
-
- audit_get_watch(w);
- krule->watch = watch = w;
- break;
- }
-
- if (!watch_found) {
- get_inotify_watch(&parent->wdata);
- watch->parent = parent;
-
- list_add(&watch->wlist, &parent->watches);
- }
- list_add(&krule->rlist, &watch->rules);
-}
-
-/* Find a matching watch entry, or add this one.
- * Caller must hold audit_filter_mutex. */
-static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp,
- struct nameidata *ndw)
-{
- struct audit_watch *watch = krule->watch;
- struct inotify_watch *i_watch;
- struct audit_parent *parent;
- int ret = 0;
-
- /* update watch filter fields */
- if (ndw) {
- watch->dev = ndw->path.dentry->d_inode->i_sb->s_dev;
- watch->ino = ndw->path.dentry->d_inode->i_ino;
- }
-
- /* The audit_filter_mutex must not be held during inotify calls because
- * we hold it during inotify event callback processing. If an existing
- * inotify watch is found, inotify_find_watch() grabs a reference before
- * returning.
- */
- mutex_unlock(&audit_filter_mutex);
-
- if (inotify_find_watch(audit_ih, ndp->path.dentry->d_inode,
- &i_watch) < 0) {
- parent = audit_init_parent(ndp);
- if (IS_ERR(parent)) {
- /* caller expects mutex locked */
- mutex_lock(&audit_filter_mutex);
- return PTR_ERR(parent);
- }
- } else
- parent = container_of(i_watch, struct audit_parent, wdata);
-
- mutex_lock(&audit_filter_mutex);
-
- /* parent was moved before we took audit_filter_mutex */
- if (parent->flags & AUDIT_PARENT_INVALID)
- ret = -ENOENT;
- else
- audit_add_to_parent(krule, parent);
-
- /* match get in audit_init_parent or inotify_find_watch */
- put_inotify_watch(&parent->wdata);
- return ret;
-}
-
static u64 prio_low = ~0ULL/2;
static u64 prio_high = ~0ULL/2 - 1;
@@ -1297,7 +889,7 @@ static inline int audit_add_rule(struct audit_entry *entry)
/* Avoid calling path_lookup under audit_filter_mutex. */
if (watch) {
- err = audit_get_nd(watch->path, &ndp, &ndw);
+ err = audit_get_nd(audit_watch_path(watch), &ndp, &ndw);
if (err)
goto error;
}
@@ -1312,7 +904,7 @@ static inline int audit_add_rule(struct audit_entry *entry)
}
/* entry->rule.watch may have changed during audit_add_watch() */
watch = entry->rule.watch;
- h = audit_hash_ino((u32)watch->ino);
+ h = audit_hash_ino((u32)audit_watch_inode(watch));
list = &audit_inode_hash[h];
}
if (tree) {
@@ -1364,7 +956,7 @@ error:
static inline int audit_del_rule(struct audit_entry *entry)
{
struct audit_entry *e;
- struct audit_watch *watch, *tmp_watch = entry->rule.watch;
+ struct audit_watch *watch = entry->rule.watch;
struct audit_tree *tree = entry->rule.tree;
struct list_head *list;
LIST_HEAD(inotify_list);
@@ -1386,29 +978,8 @@ static inline int audit_del_rule(struct audit_entry *entry)
goto out;
}
- watch = e->rule.watch;
- if (watch) {
- struct audit_parent *parent = watch->parent;
-
- list_del(&e->rule.rlist);
-
- if (list_empty(&watch->rules)) {
- audit_remove_watch(watch);
-
- if (list_empty(&parent->watches)) {
- /* Put parent on the inotify un-registration
- * list. Grab a reference before releasing
- * audit_filter_mutex, to be released in
- * audit_inotify_unregister().
- * If filesystem is going away, just leave
- * the sucker alone, eviction will take
- * care of it.
- */
- if (pin_inotify_watch(&parent->wdata))
- list_add(&parent->ilist, &inotify_list);
- }
- }
- }
+ if (e->rule.watch)
+ audit_remove_watch_rule(&e->rule, &inotify_list);
if (e->rule.tree)
audit_remove_tree_rule(&e->rule);
@@ -1430,8 +1001,8 @@ static inline int audit_del_rule(struct audit_entry *entry)
audit_inotify_unregister(&inotify_list);
out:
- if (tmp_watch)
- audit_put_watch(tmp_watch); /* match initial get */
+ if (watch)
+ audit_put_watch(watch); /* match initial get */
if (tree)
audit_put_tree(tree); /* that's the temporary one */
@@ -1785,7 +1356,7 @@ static int update_lsm_rule(struct audit_krule *r)
list_del(&r->list);
} else {
if (watch) {
- list_add(&nentry->rule.rlist, &watch->rules);
+ list_add(&nentry->rule.rlist, audit_watch_rules(watch));
list_del(&r->rlist);
} else if (tree)
list_replace_init(&r->rlist, &nentry->rule.rlist);
@@ -1821,27 +1392,3 @@ int audit_update_lsm_rules(void)
return err;
}
-
-/* Update watch data in audit rules based on inotify events. */
-void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask,
- u32 cookie, const char *dname, struct inode *inode)
-{
- struct audit_parent *parent;
-
- parent = container_of(i_watch, struct audit_parent, wdata);
-
- if (mask & (IN_CREATE|IN_MOVED_TO) && inode)
- audit_update_watch(parent, dname, inode->i_sb->s_dev,
- inode->i_ino, 0);
- else if (mask & (IN_DELETE|IN_MOVED_FROM))
- audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1);
- /* inotify automatically removes the watch and sends IN_IGNORED */
- else if (mask & (IN_DELETE_SELF|IN_UNMOUNT))
- audit_remove_parent_watches(parent);
- /* inotify does not remove the watch, so remove it manually */
- else if(mask & IN_MOVE_SELF) {
- audit_remove_parent_watches(parent);
- inotify_remove_watch_locked(audit_ih, i_watch);
- } else if (mask & IN_IGNORED)
- put_inotify_watch(i_watch);
-}