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

commit 50c0ada627f56c92f5953a8bf9158b045ad026a1 upstream.

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: 4baf1e33d0 ("virtio_net: enable VQs early")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220617072949.30734-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jason Wang 2022-06-17 15:29:49 +08:00 committed by Greg Kroah-Hartman
parent c0a28f2ddf
commit f7b8fb4584

View File

@ -3171,14 +3171,20 @@ static int virtnet_probe(struct virtio_device *vdev)
}
}
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");