Re: [PATCH v2] vhost-user-blk: Fail gracefully on too large queue size

[Raphael Norwitz <raphael.norwitz@nutanix.com>]

On Tue, Apr 13, 2021 at 06:56:54PM +0200, Kevin Wolf wrote:
> virtio_add_queue() aborts when queue_size > VIRTQUEUE_MAX_SIZE, so
> vhost_user_blk_device_realize() should check this before calling it.
> 
> Simple reproducer:
> 
> qemu-system-x86_64 \
>     -chardev null,id=foo \
>     -device vhost-user-blk-pci,queue-size=4096,chardev=foo
>
> Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1935014
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  hw/block/vhost-user-blk.c | 5 +++++
>  1 file changed, 5 insertions(+)

Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

> 
> diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> index 0b5b9d44cd..f5e9682703 100644
> --- a/hw/block/vhost-user-blk.c
> +++ b/hw/block/vhost-user-blk.c
> @@ -467,6 +467,11 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
>          error_setg(errp, "vhost-user-blk: queue size must be non-zero");
>          return;
>      }
> +    if (s->queue_size > VIRTQUEUE_MAX_SIZE) {
> +        error_setg(errp, "vhost-user-blk: queue size must not exceed %d",
> +                   VIRTQUEUE_MAX_SIZE);
> +        return;
> +    }
>  
>      if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
>          return;
> -- 
> 2.30.2
>