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

[Philippe Mathieu-Daudé]

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:

-- >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>