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

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

[Stefan Hajnoczi]

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>
---
 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

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

[Peter Maydell]

On Mon, 16 May 2022 at 16:57, Stefan Hajnoczi <stefanha@redhat.com> 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>
> ---
>  contrib/vhost-user-scsi/vhost-user-scsi.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

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

[Raphael Norwitz]

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
>