diff --git a/kernel/rtmutex-debug.c b/kernel/rtmutex-debug.c
index cb1ced6..a2e7e72 100644
--- a/kernel/rtmutex-debug.c
+++ b/kernel/rtmutex-debug.c
@@ -94,8 +94,10 @@
 		return;
 	}
 
-	if (!debug_locks_off())
+	if (!debug_locks_off()) {
+		rcu_read_unlock();
 		return;
+	}
 
 	printk("\n============================================\n");
 	printk(  "[ BUG: circular locking deadlock detected! ]\n");