Re: [dpdk-dev] [PATCH v2 2/3] vhost: fix fd leak in dirty logging setup

[Xia, Chenbo]

Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Monday, November 9, 2020 7:26 PM
> To: dev@dpdk.org; Ding, Xuan <xuan.d...@intel.com>;
> step...@networkplumber.org; tho...@monjalon.net; sta...@dpdk.org; Xia,
> Chenbo <chenbo....@intel.com>
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>
> Subject: [PATCH v2 2/3] vhost: fix fd leak in dirty logging setup
> 
> This patch fixes a file descriptor leak which happens
> in the error path of vhost_user_set_log_base().
> 
> Fixes: 4796ad63ba1f ("examples/vhost: import userspace vhost application")
> Cc: sta...@dpdk.org
> 
> Reported-by: Xuan Ding <xuan.d...@intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> ---
>  lib/librte_vhost/vhost_user.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 473fd778ca..e4ad5f6baf 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -2076,7 +2076,7 @@ vhost_user_set_log_base(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
> 
>       if (fd < 0) {
>               VHOST_LOG_CONFIG(ERR, "invalid log fd: %d\n", fd);
> -             return RTE_VHOST_MSG_RESULT_ERR;
> +             goto close_msg_fds;

I remember we have agreed on simply return here? As I look back to v1, I think
you may modify the wrong place. Because I see another 'goto close_msg_fds' is
deleted compared with v1 😊.

        if (msg->size != sizeof(VhostUserLog)) {
                VHOST_LOG_CONFIG(ERR,
                        "invalid log base msg size: %"PRId32" != %d\n",
                        msg->size, (int)sizeof(VhostUserLog));
-               return RTE_VHOST_MSG_RESULT_ERR;
+               goto close_msg_fds;

Thanks!
Chenbo

>       }
> 
>       if (msg->size != sizeof(VhostUserLog)) {
> @@ -2094,7 +2094,7 @@ vhost_user_set_log_base(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
>               VHOST_LOG_CONFIG(ERR,
>                       "log offset %#"PRIx64" and log size %#"PRIx64"
> overflow\n",
>                       off, size);
> -             return RTE_VHOST_MSG_RESULT_ERR;
> +             goto close_msg_fds;
>       }
> 
>       VHOST_LOG_CONFIG(INFO,
> @@ -2131,6 +2131,10 @@ vhost_user_set_log_base(struct virtio_net **pdev,
> struct VhostUserMsg *msg,
>       msg->fd_num = 0;
> 
>       return RTE_VHOST_MSG_RESULT_REPLY;
> +
> +close_msg_fds:
> +     close_msg_fds(msg);
> +     return RTE_VHOST_MSG_RESULT_ERR;
>  }
> 
>  static int vhost_user_set_log_fd(struct virtio_net **pdev __rte_unused,
> --
> 2.26.2