Hi, Chen bo, Maxime, Please help to review the patch below. Thanks. Gaoxiang. -------- Forwarding messages -------- From: "Gaoxiang Liu" Date: 2022-06-22 09:19:44 To: maxime.coquelin@redhat.com,chenbo.xia@intel.com Cc: dev@dpdk.org,liugaoxiang@huawei.com,"Gaoxiang Liu" ,stable@dpdk.org Subject: [PATCH v2] vhost: fix avail idx update error when desc copy failed When copy_desc_to_mbuf function failed, i added 1. And last_avail_idx added i, other than i - 1. It may cause that the first mbuf in mbuf-list is dropped, the second mbuf in mbuf-list is received in the following rx procedure. And The pkt_len of the second mbuf is zero, resulting in segment fault when parsing the mbuf. Fixes: 0fd5608ef97f ("vhost: handle mbuf allocation failure") Cc: stable@dpdk.org Signed-off-by: Gaoxiang Liu --- v2: * Fixed other idx update errors. --- lib/vhost/virtio_net.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c index 68a26eb17d..eb254e1024 100644 --- a/lib/vhost/virtio_net.c +++ b/lib/vhost/virtio_net.c @@ -2850,11 +2850,11 @@ virtio_dev_tx_split(struct virtio_net *dev, struct vhost_virtqueue *vq, if (dropped) rte_pktmbuf_free_bulk(&pkts[i - 1], count - i + 1); - vq->last_avail_idx += i; + vq->last_avail_idx += i - dropped; do_data_copy_dequeue(vq); - if (unlikely(i < count)) - vq->shadow_used_idx = i; + if (unlikely((i - dropped) < count)) + vq->shadow_used_idx = i - dropped; if (likely(vq->shadow_used_idx)) { flush_shadow_used_ring_split(dev, vq); vhost_vring_call_split(dev, vq); -- 2.32.0