On Thu, 26 Jun 2025 10:14:45 +0800 Jason Wang wrote:
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -690,13 +690,13 @@ static int vhost_net_build_xdp(struct
> vhost_net_virtqueue *nvq,
> if (unlikely(!buf))
> return -ENOMEM;
>
> - copied = copy_from_iter(buf, sock_hlen, from);
> - if (copied != sock_hlen) {
> + copied = copy_from_iter(buf + pad - sock_hlen, len, from);
> + if (copied != len) {
> ret = -EFAULT;
> goto err;
> }
>
> - gso = buf;
> + gso = buf + pad - sock_hlen;
>
> if (!sock_hlen)
> memset(buf, 0, pad);
> @@ -715,12 +715,8 @@ static int vhost_net_build_xdp(struct
> vhost_net_virtqueue *nvq,
> }
> }
>
> - len -= sock_hlen;
we used to adjust @len here, now we don't..
> - copied = copy_from_iter(buf + pad, len, from);
> - if (copied != len) {
> - ret = -EFAULT;
> - goto err;
> - }
> + /* pad contains sock_hlen */
> + memcpy(buf, buf + pad - sock_hlen, sock_hlen);
>
> xdp_init_buff(xdp, buflen, NULL);
> xdp_prepare_buff(xdp, buf, pad, len, true);
.. yet we still use len as the packet size here.
--
pw-bot: cr
