[dpdk-dev] [PATCH 7/7] vhost: check virtqueue metadata pointer

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch checks whether the virtqueue metadata pointer
is valid before dereferencing it. It is not considered
a fix as earlier patch ensures there are no holes in the
array of virtqueue metadata pointers.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/librte_vhost/vhost.c      | 11 +++++++++++
 lib/librte_vhost/vhost_user.c | 12 ++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index e92ff618ac..8a151a9c1d 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -544,6 +544,11 @@ init_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 	}
 
 	vq = dev->virtqueue[vring_idx];
+	if (!vq) {
+		VHOST_LOG_CONFIG(ERR, "Virtqueue not allocated (%d)\n",
+				vring_idx);
+		return;
+	}
 
 	memset(vq, 0, sizeof(struct vhost_virtqueue));
 
@@ -570,6 +575,12 @@ reset_vring_queue(struct virtio_net *dev, uint32_t vring_idx)
 	}
 
 	vq = dev->virtqueue[vring_idx];
+	if (!vq) {
+		VHOST_LOG_CONFIG(ERR, "Virtqueue not allocated (%d)\n",
+				vring_idx);
+		return;
+	}
+
 	callfd = vq->callfd;
 	init_vring_queue(dev, vring_idx);
 	vq->callfd = callfd;
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index d20c8c57ad..8a8726f8b8 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -1235,6 +1235,9 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg,
 	for (i = 0; i < dev->nr_vring; i++) {
 		struct vhost_virtqueue *vq = dev->virtqueue[i];
 
+		if (!vq)
+			continue;
+
 		if (vq->desc || vq->avail || vq->used) {
 			/*
 			 * If the memory table got updated, the ring addresses
@@ -1556,6 +1559,9 @@ vhost_user_set_inflight_fd(struct virtio_net **pdev, VhostUserMsg *msg,
 
 	for (i = 0; i < num_queues; i++) {
 		vq = dev->virtqueue[i];
+		if (!vq)
+			continue;
+
 		if (vq_is_packed(dev)) {
 			vq->inflight_packed = addr;
 			vq->inflight_packed->desc_num = queue_size;
@@ -2310,6 +2316,9 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg,
 		for (i = 0; i < dev->nr_vring; i++) {
 			struct vhost_virtqueue *vq = dev->virtqueue[i];
 
+			if (!vq)
+				continue;
+
 			vhost_user_iotlb_cache_insert(vq, imsg->iova, vva,
 					len, imsg->perm);
 
@@ -2321,6 +2330,9 @@ vhost_user_iotlb_msg(struct virtio_net **pdev, struct VhostUserMsg *msg,
 		for (i = 0; i < dev->nr_vring; i++) {
 			struct vhost_virtqueue *vq = dev->virtqueue[i];
 
+			if (!vq)
+				continue;
+
 			vhost_user_iotlb_cache_remove(vq, imsg->iova,
 					imsg->size);
 
-- 
2.26.2