--- y/drivers/input/input.c
+++ n/drivers/input/input.c
@@ -781,9 +781,8 @@ static void input_disconnect_device(stru
 	 * not to protect access to dev->going_away but rather to ensure
 	 * that there are no threads in the middle of input_open_device()
 	 */
-	mutex_lock(&dev->mutex);
 	dev->going_away = true;
-	mutex_unlock(&dev->mutex);
+	synchronize_rcu();
 
 	spin_lock_irq(&dev->event_lock);