Re: [Freedreno] [PATCH v2 04/10] drm/msm/hdmi: fix memory corruption with too many bridges

Kuogee Hsieh
2022-09-22T19:53:24Z

On 9/13/2022 1:53 AM, Johan Hovold wrote:
> Add the missing sanity check on the bridge counter to avoid corrupting
> data beyond the fixed-sized bridge array in case there are ever more
> than eight bridges.
>
> Fixes: a3376e3ec81c ("drm/msm: convert to drm_bridge")
> Cc: stable@vger.kernel.org # 3.12
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
> ---
> drivers/gpu/drm/msm/hdmi/hdmi.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/hdmi/hdmi.c b/drivers/gpu/drm/msm/hdmi/hdmi.c
> index 93fe61b86967..a0ed6aa8e4e1 100644
> --- a/drivers/gpu/drm/msm/hdmi/hdmi.c
> +++ b/drivers/gpu/drm/msm/hdmi/hdmi.c
> @@ -300,6 +300,11 @@ int msm_hdmi_modeset_init(struct hdmi *hdmi,
> struct platform_device *pdev = hdmi->pdev;
> int ret;
>
> + if (priv->num_bridges == ARRAY_SIZE(priv->bridges)) {
> + DRM_DEV_ERROR(dev->dev, "too many bridges\n");
> + return -ENOSPC;
> + }
> +
> hdmi->dev = dev;
> hdmi->encoder = encoder;
>