This is a note to let you know that I've just added the patch titled virtio-net: fix race between ndo_open() and virtio_device_ready() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: virtio-net-fix-race-between-ndo_open-and-virtio_device_ready.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 50c0ada627f56c92f5953a8bf9158b045ad026a1 Mon Sep 17 00:00:00 2001 From: Jason Wang <jasowang@xxxxxxxxxx> Date: Fri, 17 Jun 2022 15:29:49 +0800 Subject: virtio-net: fix race between ndo_open() and virtio_device_ready() From: Jason Wang <jasowang@xxxxxxxxxx> 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 <jasowang@xxxxxxxxxx> Message-Id: <20220617072949.30734-1-jasowang@xxxxxxxxxx> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 db05b5e930be..8a5810bcb839 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3655,14 +3655,20 @@ static int virtnet_probe(struct virtio_device *vdev) if (vi->has_rss || vi->has_rss_hash_report) virtnet_init_default_rss(vi); - 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"); -- 2.37.0 Patches currently in stable-queue which might be from jasowang@xxxxxxxxxx are queue-5.15/virtio-net-fix-race-between-ndo_open-and-virtio_device_ready.patch