From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Date: Tue, 19 Jul 2016 02:39:53 +0000 (+0800)
Subject: net/virtio: fix crash on null dereference
X-Git-Tag: spdx-start~6121
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=834ac655bae247acee5016dc46400f456db047fd;p=dpdk.git

net/virtio: fix crash on null dereference

The rxq/txq for the queue_release callback could be NULL, say when
rte_eth_dev_configure() fails that the queue is not setup at all.

Do a simple NULL check would fix the crash issue.

Fixes: 01ad44fd374f ("net/virtio: split Rx/Tx queue")

Reported-by: Olivier Matz <olivier.matz@6wind.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
---

diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 9aba044c66..724517e2b1 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -468,13 +468,19 @@ void
 virtio_dev_rx_queue_release(void *rxq)
 {
 	struct virtnet_rx *rxvq = rxq;
-	struct virtqueue *vq = rxvq->vq;
-	/* rxvq is freed when vq is freed, and as mz should be freed after the
+	struct virtqueue *vq;
+	const struct rte_memzone *mz;
+
+	if (rxvq == NULL)
+		return;
+
+	/*
+	 * rxvq is freed when vq is freed, and as mz should be freed after the
 	 * del_queue, so we reserve the mz pointer first.
 	 */
-	const struct rte_memzone *mz = rxvq->mz;
+	vq = rxvq->vq;
+	mz = rxvq->mz;
 
-	/* no need to free rxq as vq and rxq are allocated together */
 	virtio_dev_queue_release(vq);
 	rte_memzone_free(mz);
 }
@@ -554,12 +560,20 @@ void
 virtio_dev_tx_queue_release(void *txq)
 {
 	struct virtnet_tx *txvq = txq;
-	struct virtqueue *vq = txvq->vq;
-	/* txvq is freed when vq is freed, and as mz should be freed after the
+	struct virtqueue *vq;
+	const struct rte_memzone *mz;
+	const struct rte_memzone *hdr_mz;
+
+	if (txvq == NULL)
+		return;
+
+	/*
+	 * txvq is freed when vq is freed, and as mz should be freed after the
 	 * del_queue, so we reserve the mz pointer first.
 	 */
-	const struct rte_memzone *hdr_mz = txvq->virtio_net_hdr_mz;
-	const struct rte_memzone *mz = txvq->mz;
+	vq = txvq->vq;
+	mz = txvq->mz;
+	hdr_mz = txvq->virtio_net_hdr_mz;
 
 	virtio_dev_queue_release(vq);
 	rte_memzone_free(mz);