--- x/net/core/dev.c
+++ y/net/core/dev.c
@@ -11606,8 +11606,6 @@ void free_netdev(struct net_device *dev)
 		return;
 	}
 
-	mutex_destroy(&dev->lock);
-
 	kfree(dev->ethtool);
 	netif_free_tx_queues(dev);
 	netif_free_rx_queues(dev);