Re: [PATCH 3/7] vhost-user-gpu: fix memory leak in vg_resource_attach_backing

[Li Qiang <liq3ea@gmail.com>]

P J P <ppandit@redhat.com> 于2021年5月5日周三 下午3:39写道：
>
> +-- On Tue, 4 May 2021, Li Qiang wrote --+
> | Check whether the 'res' has already been attach_backing to avoid
> | memory leak.
> |
> | Signed-off-by: Li Qiang <liq3ea@163.com>
> | ---
> |  contrib/vhost-user-gpu/vhost-user-gpu.c | 5 +++++
> |  1 file changed, 5 insertions(+)
> |
> | diff --git a/contrib/vhost-user-gpu/vhost-user-gpu.c b/contrib/vhost-user-gpu/vhost-user-gpu.c
> | index b5e153d0d6..0437e52b64 100644
> | --- a/contrib/vhost-user-gpu/vhost-user-gpu.c
> | +++ b/contrib/vhost-user-gpu/vhost-user-gpu.c
> | @@ -489,6 +489,11 @@ vg_resource_attach_backing(VuGpu *g,
> |          return;
> |      }
> |
> | +    if (res->iov) {
> | +        cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
> | +        return;
> | +    }
> | +
> |      ret = vg_create_mapping_iov(g, &ab, cmd, &res->iov);
> |      if (ret != 0) {
> |          cmd->error = VIRTIO_GPU_RESP_ERR_UNSPEC;
>
>
> * While it'll work, should the check be done by 'virtio_gpu_find_resource()'
>   before returning 'res' ? ie. if 'res->iov' is being used, then it's similar
>   case as 'illegal resource specified %d'.

No, 'virtio_gpu_find_resource' is a general function and is used in a lot place
and 'res->iov' is specified to 'vg_resource_[de]attach_backing' so we should do
this check in 'vg_resource_attach_backing'.

Thanks,
Li Qiang

>
>
> Thank you.
> --
>  - P J P
> 8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D
>