eCryptfs: use after free in ecryptfs_release_messaging()

We're freeing the list iterator so we should be using the _safe()
version of hlist_for_each_entry().

Fixes: 88b4a07e6610 ("[PATCH] eCryptfs: Public key transport mechanism")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
index 286f10b..4f457d5 100644 (file)
--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -442,15 +442,16 @@ void ecryptfs_release_messaging(void)
        }
        if (ecryptfs_daemon_hash) {
                struct ecryptfs_daemon *daemon;
+               struct hlist_node *n;
                int i;
 
                mutex_lock(&ecryptfs_daemon_hash_mux);
                for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
                        int rc;
 
-                       hlist_for_each_entry(daemon,
-                                            &ecryptfs_daemon_hash[i],
-                                            euid_chain) {
+                       hlist_for_each_entry_safe(daemon, n,
+                                                 &ecryptfs_daemon_hash[i],
+                                                 euid_chain) {
                                rc = ecryptfs_exorcise_daemon(daemon);
                                if (rc)
                                        printk(KERN_ERR "%s: Error whilst "