From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: [PATCH 1/2] virtio: fixed segmentation fault in
 queue_release
Date: Tue, 20 Oct 2015 11:44:07 -0700
Message-ID: <20151020114407.58972ed5@xeon-e3>
References: <PATCH>
 <1445355462-16521-1-git-send-email-bernard.iremonger@intel.com>
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To: Bernard Iremonger <bernard.iremonger@intel.com>
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On Tue, 20 Oct 2015 16:37:41 +0100
Bernard Iremonger <bernard.iremonger@intel.com> wrote:

> if input parameter vq is NULL, hw = vq->hw, causes a segmentation fault.
> 
> Signed-off-by: Bernard Iremonger <bernard.iremonger@intel.com>
> ---
>  drivers/net/virtio/virtio_ethdev.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index 465d3cd..147aca1 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -239,9 +239,10 @@ 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;
> +	struct virtio_hw *hw;
>  
>  	if (vq) {
> +		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);

This could only happen for the case of the control vq.
Others are guaranteed to be non NULL by rte_ethdev.

Acked-by: Stephen Hemminger <stephen@networkplumber.org>