From: Johan Hovold <johan+linaro@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx # 5.17
Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
Tested-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Patchwork: https://patchwork.freedesktop.org/patch/502664/
Link: https://lore.kernel.org/r/20220913085320.8577-3-johan+linaro@xxxxxxxxxx
Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
--
2.38.1
