[dpdk-dev] [PATCH] vhost: fix buffer length calculation

[Wang, Zhihong]

> -----Original Message-----
> From: Bie, Tiwei
> Sent: Tuesday, July 17, 2018 9:11 PM
> To: maxime.coquelin at redhat.com; Wang, Zhihong
> <zhihong.wang at intel.com>; dev at dpdk.org
> Cc: Wang, Yinan <yinan.wang at intel.com>; Yao, Lei A <lei.a.yao at intel.com>
> Subject: [PATCH] vhost: fix buffer length calculation
> 
> Fixes: fd68b4739d2c ("vhost: use buffer vectors in dequeue path")
> 
> Reported-by: Yinan Wang <yinan.wang at intel.com>
> Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
> ---
>  lib/librte_vhost/virtio_net.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 2b7ffcf92..07cc0c845 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -720,7 +720,8 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
>  				uint16_t hdr_vec_idx = 0;
> 
>  				while (remain) {
> -					len = remain;
> +					len = RTE_MIN(remain,
> +
> 	buf_vec[hdr_vec_idx].buf_len);
>  					dst = buf_vec[hdr_vec_idx].buf_addr;
>  					rte_memcpy((void *)(uintptr_t)dst,
>  							(void *)(uintptr_t)src,
> @@ -747,7 +748,7 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
>  			hdr_addr = 0;
>  		}
> 
> -		cpy_len = RTE_MIN(buf_len, mbuf_avail);
> +		cpy_len = RTE_MIN(buf_avail, mbuf_avail);
> 
>  		if (likely(cpy_len > MAX_BATCH_LEN ||
>  					vq->batch_copy_nb_elems >= vq-
> >size)) {
> @@ -1112,7 +1113,8 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct
> vhost_virtqueue *vq,
>  			 * in a contiguous virtual area.
>  			 */
>  			while (remain) {
> -				len = remain;
> +				len = RTE_MIN(remain,
> +					buf_vec[hdr_vec_idx].buf_len);
>  				src = buf_vec[hdr_vec_idx].buf_addr;
>  				rte_memcpy((void *)(uintptr_t)dst,
>  						   (void *)(uintptr_t)src, len);
> --
> 2.18.0

Acked-by: Zhihong Wang <zhihong.wang at intel.com>

Thanks