Re: [PATCH v2 02/10] drm/msm/dp: fix memory corruption with too many bridges

[Dmitry Baryshkov]

On 13/09/2022 11:53, Johan Hovold wrote:

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: sta...@vger.kernel.org  # 5.17
Signed-off-by: Johan Hovold 


Reviewed-by: Dmitry Baryshkov 

--
With best wishes
Dmitry

Re: [Freedreno] [PATCH v2 02/10] drm/msm/dp: fix memory corruption with too many bridges

[Kuogee Hsieh]

On 9/13/2022 1:53 AM, Johan Hovold wrote:

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: sta...@vger.kernel.org  # 5.17
Signed-off-by: Johan Hovold 

Tested-by: Kuogee Hsieh 
Reviewed-by: Kuogee Hsieh 

---
  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 3e284fed8d30..fbe950edaefe 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1604,6 +1604,12 @@ 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);

[PATCH v2 02/10] drm/msm/dp: fix memory corruption with too many bridges

[Johan Hovold]

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: sta...@vger.kernel.org  # 5.17
Signed-off-by: Johan Hovold 
---
 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 3e284fed8d30..fbe950edaefe 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -1604,6 +1604,12 @@ 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);
-- 
2.35.1