caif_virtio: fix race between virtio_device_ready() and ndo_open()

We currently depend on probe() calling virtio_device_ready() -
which happens 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 (e.g. TX) 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: 0d2e1a2926 ("caif_virtio: Introduce caif over virtio")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220620051115.3142-3-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Jason Wang 2022-06-20 13:11:14 +08:00 committed by Michael S. Tsirkin
parent 50c0ada627
commit 11a37eb668

View file

@ -722,13 +722,21 @@ static int cfv_probe(struct virtio_device *vdev)
/* Carrier is off until netdevice is opened */
netif_carrier_off(netdev);
/* serialize netdev register + virtio_device_ready() with ndo_open() */
rtnl_lock();
/* register Netdev */
err = register_netdev(netdev);
err = register_netdevice(netdev);
if (err) {
rtnl_unlock();
dev_err(&vdev->dev, "Unable to register netdev (%d)\n", err);
goto err;
}
virtio_device_ready(vdev);
rtnl_unlock();
debugfs_init(cfv);
return 0;