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

Johan Hovold
2022-09-13T08:58:38Z

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>
---
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;

--
2.35.1