From: Johan Hovold johan+linaro@kernel.org
commit 74466e46e7543c7f74f1502181e9ba93f7521374 upstream.
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: 8a3b4c17f863 ("drm/msm/dp: employ bridge mechanism for display enable and disable") Cc: stable@vger.kernel.org # 5.17 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 Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Patchwork: https://patchwork.freedesktop.org/patch/502664/ Link: https://lore.kernel.org/r/20220913085320.8577-3-johan+linaro@kernel.org Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/msm/dp/dp_display.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index bfd0aeff3f0d..be9ed891dc3f 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -1597,6 +1597,12 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev, return -EINVAL;
priv = dev->dev_private; + + if (priv->num_bridges == ARRAY_SIZE(priv->bridges)) { + DRM_DEV_ERROR(dev->dev, "too many bridges\n"); + return -ENOSPC; + } + dp_display->drm_dev = dev;
dp_priv = container_of(dp_display, struct dp_display_private, dp_display);