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

["Xia, Chenbo" <chenbo.xia@intel.com>]

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Tuesday, October 20, 2020 1:34 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; amorenoz@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH 7/7] vhost: check virtqueue metadata pointer
> 
> 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

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>