From 9f035d1fb30648fe70ee01627eb131c56d699b35 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 13 Sep 2022 10:53:13 +0200 Subject: [PATCH] drm/msm/dsi: fix memory corruption with too many bridges commit 2e786eb2f9cebb07e317226b60054df510b60c65 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: a689554ba6ed ("drm/msm: Initial add DSI connector support") Cc: stable@vger.kernel.org # 4.1 Signed-off-by: Johan Hovold Tested-by: Kuogee Hsieh Reviewed-by: Kuogee Hsieh Reviewed-by: Dmitry Baryshkov Patchwork: https://patchwork.freedesktop.org/patch/502668/ Link: https://lore.kernel.org/r/20220913085320.8577-4-johan+linaro@kernel.org Signed-off-by: Abhinav Kumar Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/msm/dsi/dsi.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c index 122fadcf7cc1..fb8b21837c29 100644 --- a/drivers/gpu/drm/msm/dsi/dsi.c +++ b/drivers/gpu/drm/msm/dsi/dsi.c @@ -212,6 +212,12 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, 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; + } + msm_dsi->dev = dev; ret = msm_dsi_host_modeset_init(msm_dsi->host, dev);