On Wed, Jul 16, 2025 at 07:57:17PM +0800, Zigit Zo wrote:
> The deadlock appears in a stack trace like:
>
> virtnet_probe()
> rtnl_lock()
> virtio_config_changed_work()
> netdev_notify_peers()
> rtnl_lock()
>
> It happens if the VMM sends a VIRTIO_NET_S_ANNOUNCE request while the
> virtio-net driver is still probing.
>
> The config_work in probe() will get scheduled until virtnet_open() enables
> the config change notification via virtio_config_driver_enable().
>
> Fixes: df28de7b0050 ("virtio-net: synchronize operstate with admin state on up/down")
> Signed-off-by: Zigit Zo <zuozhijie@xxxxxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> v3 -> v2:
> * Simplify the changes.
> v1 -> v2:
> * Check vi->status in virtnet_open().
> * https://lore.kernel.org/netdev/20250702103722.576219-1-zuozhijie@xxxxxxxxxxxxx/
> v1:
> * https://lore.kernel.org/netdev/20250630095109.214013-1-zuozhijie@xxxxxxxxxxxxx/
> ---
> drivers/net/virtio_net.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 5d674eb9a0f2..82b4a2a2b8c4 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -7059,7 +7059,7 @@ static int virtnet_probe(struct virtio_device *vdev)
> otherwise get link status from config. */
> netif_carrier_off(dev);
> if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
> - virtnet_config_changed_work(&vi->config_work);
> + virtio_config_changed(vi->vdev);
> } else {
> vi->status = VIRTIO_NET_S_LINK_UP;
> virtnet_update_settings(vi);
>
> base-commit: dae7f9cbd1909de2b0bccc30afef95c23f93e477
> --
> 2.49.0
