Re: [PATCH 07/18] vhost-vdpa: tweak the error label in vhost_vdpa_add()

[Stefano Garzarella]

On Mon, Jun 21, 2021 at 12:16:39PM +0800, Jason Wang wrote:
> Introduce new error label to avoid the unnecessary checking of net
> pointer.
>
> Fixes: 1e0a84ea49b68 ("vhost-vdpa: introduce vhost-vdpa net client")
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
> net/vhost-vdpa.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 21f09c546f..0da7bc347a 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -100,19 +100,18 @@ static int vhost_vdpa_add(NetClientState *ncs, void *be)
>     net = vhost_net_init(&options);
>     if (!net) {
>         error_report("failed to init vhost_net for queue");
> -        goto err;
> +        goto err_init;
>     }
>     s->vhost_net = net;
>     ret = vhost_vdpa_net_check_device_id(net);
>     if (ret) {
> -        goto err;
> +        goto err_check;
>     }
>     return 0;
> -err:
> -    if (net) {
> -        vhost_net_cleanup(net);
> -        g_free(net);
> -    }
> +err_check:
> +    vhost_net_cleanup(net);
> +    g_free(net);

Should we set s->vhost_net to NULL to avoid use after free?

Then we should also remove the `assert(s->vhost_net)` in 
net_vhost_vdpa_init() since we can fail.

> +err_init:
>     return -1;
> }
>
> --
> 2.25.1