From: Jason Wang jasowang@redhat.com
commit 11a37eb66812ce6a06b79223ad530eb0e1d7294d upstream.
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: 0d2e1a2926b18 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/caif/caif_virtio.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
--- a/drivers/net/caif/caif_virtio.c +++ b/drivers/net/caif/caif_virtio.c @@ -721,13 +721,21 @@ static int cfv_probe(struct virtio_devic /* 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;