[PATCH net v3] virtio-net: fix recursived rtnl_lock() during probe()

[Zigit Zo]

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>
---
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