Re: [PATCH] net/vhost-vdpa: fix memory leak in vhost_vdpa_get_max_queue_pairs()

[Stefano Garzarella]

On Tue, Nov 02, 2021 at 05:05:21PM +0100, Philippe Mathieu-Daudé wrote:
> On 11/2/21 16:51, Stefano Garzarella wrote:
> > Use g_autofree to ensure that `config` is freed when
> > vhost_vdpa_get_max_queue_pairs() returns.
> >
> > Reported-by: Coverity (CID 1465228: RESOURCE_LEAK)
> > Fixes: 402378407d ("vhost-vdpa: multiqueue support")
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> > ---
> >  net/vhost-vdpa.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > index 49ab322511..373b706b90 100644
> > --- a/net/vhost-vdpa.c
> > +++ b/net/vhost-vdpa.c
> > @@ -214,7 +214,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState 
> > *peer,
> >  static int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error **errp)
> >  {
> >      unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
> > -    struct vhost_vdpa_config *config;
> > +    g_autofree struct vhost_vdpa_config *config = NULL;
> >      __virtio16 *max_queue_pairs;
> >      uint64_t features;
> >      int ret;
>
> Eventually reducing the scope:

Yep, I thought the same, moving also `config_size`, but then I switched 
to the simplest patch possible.

> -- >8 --
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -214,7 +214,6 @@ static NetClientState
> *net_vhost_vdpa_init(NetClientState *peer,
> static int vhost_vdpa_get_max_queue_pairs(int fd, int *has_cvq, Error
> **errp)
> {
>     unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
> -    struct vhost_vdpa_config *config;
>     __virtio16 *max_queue_pairs;
>     uint64_t features;
>     int ret;
> @@ -232,6 +231,8 @@ static int vhost_vdpa_get_max_queue_pairs(int fd,
> int *has_cvq, Error **errp)
>     }
>
>     if (features & (1 << VIRTIO_NET_F_MQ)) {
> +        g_autofree struct vhost_vdpa_config *config = NULL;
> +
>         config = g_malloc0(config_size + sizeof(*max_queue_pairs));
>         config->off = offsetof(struct virtio_net_config,
> max_virtqueue_pairs);
>         config->len = sizeof(*max_queue_pairs);
> ---
>
> Either ways:
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Thanks, let's see what Jason and Michael prefer.

Stefano