Linux Virtualization - May 2020 - Potential Memory Leak Bugs in drivers/gpu/drm/virtio/virtgpu_vq.c (Linux 5.6).

On Thu, May 28, 2020 at 03:57:05PM +0800, Dongyang Zhan
wrote:
> Hi,
> My name is Dongyang Zhan, I am a security researcher.
> Currently, I found two possible memory bugs in
> drivers/gpu/drm/virtio/virtgpu_vq.c (Linux 5.6).
> I hope you can help me to confirm them. Thank you.
Sorry.  Not confirmed.  You should do a better job verifying your
claims before bugging people.
> The first one is resp_buf will not be release in
> virtio_gpu_cmd_get_display_info() with the condition
> (resp_size <= MAX_INLINE_RESP_SIZE) in virtio_gpu_alloc_cmd_resp().
In that code path resp_size equals sizeof(struct
virtio_gpu_resp_display_info) which is larger than MAX_INLINE_RESP_SIZE
so the condition is never true and no leak happens.

take care,
  Gerd