Commit 50c0ada6 authored by Jason Wang's avatar Jason Wang Committed by Michael S. Tsirkin
Browse files

virtio-net: fix race between ndo_open() and virtio_device_ready() 



We currently call virtio_device_ready() after netdev
registration. Since ndo_open() can be called immediately
after register_netdev, this means there exists a race between
ndo_open() and virtio_device_ready(): the driver may start to use the
device before DRIVER_OK which violates the spec.

Fix this by switching to use register_netdevice() and protect the
virtio_device_ready() with rtnl_lock() to make sure ndo_open() can
only be called after virtio_device_ready().

Fixes: 4baf1e33 ("virtio_net: enable VQs early")
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20220617072949.30734-1-jasowang@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent c346dae4

drivers/net/virtio_net.c

+7 −1
Original line number Diff line number Diff line
@@ -3655,14 +3655,20 @@ static int virtnet_probe(struct virtio_device *vdev) 
	if (vi->has_rss || vi->has_rss_hash_report)

		virtnet_init_default_rss(vi);



	err = register_netdev(dev);

	/* serialize netdev register + virtio_device_ready() with ndo_open() */

	rtnl_lock();



	err = register_netdevice(dev);

	if (err) {

		pr_debug("virtio_net: registering device failed\n");

		rtnl_unlock();

		goto free_failover;

	}



	virtio_device_ready(vdev);



	rtnl_unlock();



	err = virtnet_cpu_notif_add(vi);

	if (err) {

		pr_debug("virtio_net: registering cpu notifier failed\n");