Re: [dpdk-dev] [PATCH] vhost: fix check if cmsg is NULL

["Tan, Jianfeng" <jianfeng.tan@intel.com>]

Hi Tomasz,

> -----Original Message-----
> From: Kulasek, TomaszX
> Sent: Friday, February 9, 2018 1:03 AM
> To: yliu@fridaylinux.org
> Cc: dev@dpdk.org; Tan, Jianfeng; stable@dpdk.org; Wodkowski, PawelX
> Subject: [PATCH] vhost: fix check if cmsg is NULL
> 
> Fixes: 6a84c37e3975 ("net/virtio-user: add vhost-user adapter layer")

Firstly, this fix line is incorrect. It shall be:

Fixes: 8f972312b8f4 ("vhost: support vhost-user")

> Cc: jianfeng.tan@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>
> Signed-off-by: Tomasz Kulasek <tomaszx.kulasek@intel.com>
> ---
>  lib/librte_vhost/socket.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
> index 83befdced..8fd47a4d8 100644
> --- a/lib/librte_vhost/socket.c
> +++ b/lib/librte_vhost/socket.c
> @@ -153,6 +153,11 @@ send_fd_message(int sockfd, char *buf, int buflen,
> int *fds, int fd_num)
>  		msgh.msg_control = control;
>  		msgh.msg_controllen = sizeof(control);
>  		cmsg = CMSG_FIRSTHDR(&msgh);

I suppose it will not return NULL as the control is defined as a variable-length array. But no harm to check it.

Thanks,
Jianfeng

> +		if (cmsg == NULL) {
> +			RTE_LOG(ERR, VHOST_CONFIG, "cmsg == NULL\n");
> +			errno = EINVAL;
> +			return -1;
> +		}
>  		cmsg->cmsg_len = CMSG_LEN(fdsize);
>  		cmsg->cmsg_level = SOL_SOCKET;
>  		cmsg->cmsg_type = SCM_RIGHTS;
> --
> 2.14.1