diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8a4370..cf3797b 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1503,7 +1503,8 @@ int kernel_kexec(void)
 	}
 
  Unlock:
-	xchg(&kexec_lock, 0);
+	if (!xchg(&kexec_lock, 0))
+		BUG();
 
 	return error;
 }