[PATCH 1/1] vhost: fix missing descriptor chains length checks

[Maxime Coquelin]

On 12/23/24 4:29 AM, Yunjian Wang wrote:
> The descriptor chains length must be greater than the Virtio-net
> header size. Otherwise, such descriptor chains sizes implies no
> packet data.
> 
> Fixes: fe8477ebbd94 ("vhost: support async packed ring dequeue")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Yunjian Wang <wangyunjian at huawei.com>
> ---
>   lib/vhost/virtio_net.c | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
> index 69901ab3b5..8fc9bfa056 100644
> --- a/lib/vhost/virtio_net.c
> +++ b/lib/vhost/virtio_net.c
> @@ -3962,6 +3962,16 @@ virtio_dev_tx_async_single_packed(struct virtio_net *dev,
>   					 VHOST_ACCESS_RO) < 0))
>   		return -1;
>   
> +	if (unlikely(buf_len <= dev->vhost_hlen)) {
> +		if (!allocerr_warned) {
> +			VHOST_DATA_LOG(dev->ifname, ERR, "Invalid buffer length.");
> +			allocerr_warned = true;
> +		}
> +		return -1;
> +	}
> +
> +	buf_len -= dev->vhost_hlen;
> +
>   	if (unlikely(virtio_dev_pktmbuf_prep(dev, pkts, buf_len))) {
>   		if (!allocerr_warned) {
>   			VHOST_DATA_LOG(dev->ifname, ERR, "Failed mbuf alloc of size %d from %s.",

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime