[PATCH v2 03/10] drm/msm/dsi: fix memory corruption with too many bridges

Johan Hovold
2022-09-13T08:58:39Z

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 <johan+linaro@kernel.org>
---
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 39bbabb5daf6..8a95c744972a 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.c
+++ b/drivers/gpu/drm/msm/dsi/dsi.c
@@ -218,6 +218,12 @@ 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);
--
2.35.1