Re: [PATCH v2] vhost-user-scsi: avoid unlink(NULL) with fd passing

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

On Mon, May 16, 2022 at 04:57:01PM +0100, Stefan Hajnoczi wrote:
> Commit 747421e949fc1eb3ba66b5fcccdb7ba051918241 ("Implements Backend
> Program conventions for vhost-user-scsi") introduced fd-passing support
> as part of implementing the vhost-user backend program conventions.
> 
> When fd passing is used the UNIX domain socket path is NULL and we must
> not call unlink(2).
> 
> The unlink(2) call is necessary when the listen socket, lsock, was
> created successfully since that means the UNIX domain socket is visible
> in the file system.
> 
> Fixes: Coverity CID 1488353
> Fixes: 747421e949fc1eb3ba66b5fcccdb7ba051918241 ("Implements Backend Program conventions for vhost-user-scsi")
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---

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

>  contrib/vhost-user-scsi/vhost-user-scsi.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/contrib/vhost-user-scsi/vhost-user-scsi.c b/contrib/vhost-user-scsi/vhost-user-scsi.c
> index b2c0f98253..9ef61cf5a7 100644
> --- a/contrib/vhost-user-scsi/vhost-user-scsi.c
> +++ b/contrib/vhost-user-scsi/vhost-user-scsi.c
> @@ -433,13 +433,16 @@ out:
>      if (vdev_scsi) {
>          g_main_loop_unref(vdev_scsi->loop);
>          g_free(vdev_scsi);
> -        unlink(opt_socket_path);
>      }
>      if (csock >= 0) {
>          close(csock);
>      }
>      if (lsock >= 0) {
>          close(lsock);
> +
> +        if (opt_socket_path) {
> +            unlink(opt_socket_path);
> +        }
>      }
>      g_free(opt_socket_path);
>      g_free(iscsi_uri);
> -- 
> 2.36.1
>