Hi Jeff,
Thanks for the patch!
On 3/6/20 2:23 AM, Jeffrey Kardatzke wrote:
> In dynamic bufmode we do not manage the buffers in the registeredbufs
> list, so do not add them there when they are initialized. Adding them
> there was causing a use after free of the list_head struct in the buffer
> when new buffers were allocated after existing buffers were freed.
Is this fixing a real issue? How you come to it?
>
> Signed-off-by: Jeffrey Kardatzke <jkardatzke@xxxxxxxxxx>
> ---
> drivers/media/platform/qcom/venus/helpers.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/qcom/venus/helpers.c b/drivers/media/platform/qcom/venus/helpers.c
> index bcc603804041..688a3593b49b 100644
> --- a/drivers/media/platform/qcom/venus/helpers.c
> +++ b/drivers/media/platform/qcom/venus/helpers.c
> @@ -1054,8 +1054,10 @@ int venus_helper_vb2_buf_init(struct vb2_buffer *vb)
> buf->size = vb2_plane_size(vb, 0);
> buf->dma_addr = sg_dma_address(sgt->sgl);
>
> - if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> + if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE &&
> + !is_dynamic_bufmode(inst)) {
If you add !is_dynamic_bufmode here, we will loose the reference frames
mechanism (see venus_helper_release_buf_ref()) which is not good.
Thus, I wonder (depending on when you observe the use-after-free issue)
does this is the correct resolution of the problem.
> list_add_tail(&buf->reg_list, &inst->registeredbufs);
> + }
>
> return 0;
> }
>
--
regards,
Stan
