Subject: Re: [PATCH net-next] net: virtio: fix virtnet_sq_free_stats initialization

From: "Michael S. Tsirkin" <[email-masked]>
Date: Fri, 12 Jul 2024 06:41:34 -0400

On Fri, Jul 12, 2024 at 09:03:30AM +0100, Jean-Philippe Brucker wrote:
> Commit c8bd1f7f3e61 ("virtio_net: add support for Byte Queue Limits")
> added two new fields to struct virtnet_sq_free_stats, but commit
> 23c81a20b998 ("net: virtio: unify code to init stats") accidentally
> removed their initialization. In the worst case this can trigger the BUG
> at lib/dynamic_queue_limits.c:99 because dql_completed() receives a
> random value as count. Initialize the whole structure.
> 
> Fixes: 23c81a20b998 ("net: virtio: unify code to init stats")
> Reported-by: Aishwarya TCV <[email-masked]>
> Signed-off-by: Jean-Philippe Brucker <[email-masked]>

Acked-by: Michael S. Tsirkin <[email-masked]>

> ---
> Both these patches are still in next so it might be possible to fix it
> up directly.

I'd be fine with squashing but I don't think it's done in net-next.

> ---
>  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 10d8674eec5d2..f014802522e0f 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -530,7 +530,7 @@ static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq,
>  	unsigned int len;
>  	void *ptr;
>  
> -	stats->bytes = stats->packets = 0;
> +	memset(stats, 0, sizeof(*stats));
>  
>  	while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) {
>  		if (!is_xdp_frame(ptr)) {
> 
> base-commit: 3fe121b622825ff8cc995a1e6b026181c48188db
> -- 
> 2.45.2