diff --git a/drivers/md/md.c b/drivers/md/md.c
index b553654cbebc..bf1c5c0e472e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7942,17 +7942,22 @@ EXPORT_SYMBOL(md_register_thread);
 
 void md_unregister_thread(struct md_thread **threadp)
 {
-	struct md_thread *thread = *threadp;
-	if (!thread)
-		return;
-	pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
-	/* Locking ensures that mddev_unlock does not wake_up a
+	struct md_thread *thread;
+
+	/*
+	 * Locking ensures that mddev_unlock does not wake_up a
 	 * non-existent thread
 	 */
 	spin_lock(&pers_lock);
+	thread = *threadp;
+	if (!thread) {
+		spin_unlock(&pers_lock);
+		return;
+	}
 	*threadp = NULL;
 	spin_unlock(&pers_lock);
 
+	pr_debug("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
 	kthread_stop(thread->tsk);
 	kfree(thread);
 }