From: Maxime Coquelin <maxime.coquelin@redhat.com>
Date: Mon, 25 Jul 2016 14:09:58 +0000 (+0200)
Subject: vhost: fix off-by-one error on descriptor number check
X-Git-Tag: spdx-start~6071
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=b7aabd7a87cee66ec3c8e010ee45e0ca70d0d914;p=dpdk.git

vhost: fix off-by-one error on descriptor number check

nr_desc is not an index but the number of descriptors,
so can be equal to the virtqueue size.

Fixes: a436f53ebfeb ("vhost: avoid dead loop chain")

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index bc00518ad2..08a73fd04b 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c
@@ -748,7 +748,7 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq,
 				break;
 
 			if (unlikely(desc->next >= vq->size ||
-				     ++nr_desc >= vq->size))
+				     ++nr_desc > vq->size))
 				return -1;
 			desc = &vq->desc[desc->next];