From f7b8fb4584456c5cdc3400b14d69d28a0c4a701a Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Fri, 17 Jun 2022 15:29:49 +0800 Subject: [PATCH] virtio-net: fix race between ndo_open() and virtio_device_ready() commit 50c0ada627f56c92f5953a8bf9158b045ad026a1 upstream. We currently call virtio_device_ready() 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 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: 4baf1e33d0842 ("virtio_net: enable VQs early") Signed-off-by: Jason Wang Message-Id: <20220617072949.30734-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ad9064df3deb..37178b078ee3 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3171,14 +3171,20 @@ static int virtnet_probe(struct virtio_device *vdev) } } - err = register_netdev(dev); + /* serialize netdev register + virtio_device_ready() with ndo_open() */ + rtnl_lock(); + + err = register_netdevice(dev); if (err) { pr_debug("virtio_net: registering device failed\n"); + rtnl_unlock(); goto free_failover; } virtio_device_ready(vdev); + rtnl_unlock(); + err = virtnet_cpu_notif_add(vi); if (err) { pr_debug("virtio_net: registering cpu notifier failed\n");