Re: [PATCH] contrib/vhost-user-blk: Clean up deallocation of VuVirtqElement

[Laurent Vivier]

Le 30/06/2022 à 10:52, Markus Armbruster a écrit :
> We allocate VuVirtqElement with g_malloc() in
> virtqueue_alloc_element(), but free it with free() in
> vhost-user-blk.c.  Harmless, but use g_free() anyway.
>
> One of the calls is guarded by a "not null" condition.  Useless,
> because it cannot be null (it's dereferenced right before), and even
> it it could be, free() and g_free() do the right thing.  Drop the
> conditional.
>
> Fixes: Coverity CID 1490290
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
> Not even compile-tested, because I can't figure out how this thing is
> supposed to be built.  Its initial commit message says "make
> vhost-user-blk", but that doesn't work anymore.
>
>   contrib/vhost-user-blk/vhost-user-blk.c | 9 +++------
>   1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/contrib/vhost-user-blk/vhost-user-blk.c 
> b/contrib/vhost-user-blk/vhost-user-blk.c
> index 9cb78ca1d0..d6932a2645 100644
> --- a/contrib/vhost-user-blk/vhost-user-blk.c
> +++ b/contrib/vhost-user-blk/vhost-user-blk.c
> @@ -106,10 +106,7 @@ static void vub_req_complete(VubReq *req)
>                     req->size + 1);
>       vu_queue_notify(vu_dev, req->vq);
>   
> -    if (req->elem) {
> -        free(req->elem);
> -    }
> -
> +    g_free(req->elem);
>       g_free(req);
>   }
>   
> @@ -243,7 +240,7 @@ static int vub_virtio_process_req(VubDev *vdev_blk,
>       /* refer to hw/block/virtio_blk.c */
>       if (elem->out_num < 1 || elem->in_num < 1) {
>           fprintf(stderr, "virtio-blk request missing headers\n");
> -        free(elem);
> +        g_free(elem);
>           return -1;
>       }
>   
> @@ -325,7 +322,7 @@ static int vub_virtio_process_req(VubDev *vdev_blk,
>       return 0;
>   
>   err:
> -    free(elem);
> +    g_free(elem);
>       g_free(req);
>       return -1;
>   }

Applied to my trivial-patches branch.

Thanks,
Laurent