Re: [dpdk-stable] [17.11 LTS PATCH v2] vhost: fix vring requests validation broken if no FD

[Tiwei Bie <tiwei.bie@intel.com>]

On Fri, Nov 15, 2019 at 11:36:30AM +0100, Maxime Coquelin wrote:
> From: Zhike Wang <wangzk320@163.com>
> 
> When VHOST_USER_VRING_NOFD_MASK is set, the fd_num is 0,
> so validate_msg_fds() will return error. In this case,
> the negotiation of vring message between vhost user front end and
> back end would fail, and as a result, vhost user link could NOT be up.
> 
> How to reproduce:
> 1.Run dpdk testpmd insides VM, which locates at host with ovs+dpdk.
> 2.Notice that inside ovs there are endless logs regarding failure to
> handle VHOST_USER_SET_VRING_CALL, and link of vm could NOT be up.
> 
> Fixes: 1f6147d9a01f ("vhost: fix possible denial of service by leaking FDs")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Zhike Wang <wangzk320@163.com>
> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/librte_vhost/vhost_user.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)

Reviewed-by: Tiwei Bie <tiwei.bie@intel.com>

Thanks!
Tiwei