lockd: unregister notifier blocks if the service fails to come up completely

scottmayhew · J. Bruce Fields · commit cb7d224f82e4 · 2016-06-30T16:35:07.000-04:00
If the lockd service fails to start up then we need to be sure that the notifier blocks are not registered, otherwise a subsequent start of the service could cause the same notifier to be registered twice, leading to soft lockups. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Cc: stable@vger.kernel.org Fixes: 0751ddf "lockd: Register callbacks on the inetaddr_chain..." Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
@@ -335,12 +335,17 @@ static struct notifier_block lockd_inet6addr_notifier = {
 };
 #endif
 
-static void lockd_svc_exit_thread(void)
+static void lockd_unregister_notifiers(void)
 {
 	unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
 #if IS_ENABLED(CONFIG_IPV6)
 	unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
 #endif
+}
+
+static void lockd_svc_exit_thread(void)
+{
+	lockd_unregister_notifiers();
 	svc_exit_thread(nlmsvc_rqst);
 }
 
@@ -462,15 +467,17 @@ int lockd_up(struct net *net)
 	 * Note: svc_serv structures have an initial use count of 1,
 	 * so we exit through here on both success and failure.
 	 */
-err_net:
+err_put:
 	svc_destroy(serv);
 err_create:
 	mutex_unlock(&nlmsvc_mutex);
 	return error;
 
 err_start:
 	lockd_down_net(serv, net);
-	goto err_net;
+err_net:
+	lockd_unregister_notifiers();
+	goto err_put;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
 
