Re: [PATCH] vsock/virtio: suppress used length validation

[Stefano Garzarella]

On Mon, Nov 22, 2021 at 04:32:01AM -0500, Michael S. Tsirkin wrote:
> It turns out that vhost vsock violates the virtio spec
> by supplying the out buffer length in the used length
> (should just be the in length).
> As a result, attempts to validate the used length fail with:
> vmw_vsock_virtio_transport virtio1: tx: used len 44 is larger than in buflen 0
>
> Since vsock driver does not use the length fox tx and
> validates the length before use for rx, it is safe to
> suppress the validation in virtio core for this driver.
>
> Reported-by: Halil Pasic <pasic@xxxxxxxxxxxxx>
> Fixes: 939779f5152d ("virtio_ring: validate used buffer length")
> Cc: "Jason Wang" <jasowang@xxxxxxxxxx>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> net/vmw_vsock/virtio_transport.c | 1 +
> 1 file changed, 1 insertion(+)

Thanks for this fix

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>


I think we should also fix vhost-vsock violation (in stable branches 
too).
@Halil do you plan to send a fix? Otherwise I can do it ;-)

Thanks,
Stefano