Re: [PATCH net v3] virtio-net: fix recursived rtnl_lock() during probe()
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2025-07-16 13:27:31
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lkml, virtualization
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 <redacted>Acked-by: Michael S. Tsirkin <mst@redhat.com>
quoted hunk ↗ jump to hunk
--- v3 -> v2: * Simplify the changes. v1 -> v2: * Check vi->status in virtnet_open(). * https://lore.kernel.org/netdev/20250702103722.576219-1-zuozhijie@bytedance.com/ (local) v1: * https://lore.kernel.org/netdev/20250630095109.214013-1-zuozhijie@bytedance.com/ (local) --- 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