[dpdk-dev] [PATCH 3/3] virtio: fix possible NULL dereference

[Ouyang, Changchun]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen at networkplumber.org]
> Sent: Saturday, August 29, 2015 12:24 AM
> To: Xie, Huawei; Ouyang, Changchun
> Cc: dev at dpdk.org; Stephen Hemminger
> Subject: [PATCH 3/3] virtio: fix possible NULL dereference
> 
> Found by Coverity. In virtio_dev_queue_release if the queue pointer is NULL,
> then driver is dereferencing it to get hw pointer.
> Also, don't do useless assignment
> 
> Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>

Acked-by: Changchun Ouyang <changchun.ouyang at intel.com>

> ---
>  drivers/net/virtio/virtio_ethdev.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c
> b/drivers/net/virtio/virtio_ethdev.c
> index 338d891..914c73d 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -239,15 +239,15 @@ virtio_set_multiple_queues(struct rte_eth_dev
> *dev, uint16_t nb_queues)
> 
>  void
>  virtio_dev_queue_release(struct virtqueue *vq) {
> -	struct virtio_hw *hw = vq->hw;
> 
>  	if (vq) {
> +		struct virtio_hw *hw = vq->hw;
> +
>  		/* Select and deactivate the queue */
>  		VIRTIO_WRITE_REG_2(hw, VIRTIO_PCI_QUEUE_SEL, vq-
> >queue_id);
>  		VIRTIO_WRITE_REG_4(hw, VIRTIO_PCI_QUEUE_PFN, 0);
> 
>  		rte_free(vq);
> -		vq = NULL;
>  	}
>  }
> 
> --
> 2.1.4