Re: [PATCH 07/37] drm/display: bridge-connector: extract drm_bridge_connector_get_bridges()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing pointer dereference when validating `connector_type`, causing the error check to be bypassed.
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commit 5a4cd30beb768eaba2369b4630833475535f79bf
Author: Luca Ceresoli <luca.ceresoli@bootlin.com>

drm/display: bridge-connector: extract drm_bridge_connector_get_bridges()

This commit splits out the code that gathers bridge pointers into a separate
function to prepare for better bridge hotplug support.

> diff --git a/drivers/gpu/drm/display/drm_bridge_connector.c b/drivers/gpu/drm/display/drm_bridge_connector.c
> --- a/drivers/gpu/drm/display/drm_bridge_connector.c
> +++ b/drivers/gpu/drm/display/drm_bridge_connector.c

[ ... ]

> @@ -772,44 +772,24 @@ static void drm_bridge_connector_put_bridges(struct drm_device *dev, void *data)
>  static struct drm_bridge_connector *
> -drm_bridge_connector_add_connector(struct drm_bridge_connector *bridge_connector)
> +drm_bridge_connector_get_bridges(struct drm_bridge_connector *bridge_connector,
> +				 int *connector_type,
> +				 unsigned int *supported_formats,
> +				 unsigned int *max_bpc,
> +				 struct i2c_adapter **ddc,
> +				 struct drm_bridge **panel_bridge,
> +				 bool *support_hdcp)
>  {

[ ... ]

>  		if (bridge->support_hdcp)
> -			support_hdcp = true;
> +			*support_hdcp = true;
>  	}
>  
>  	if (connector_type == DRM_MODE_CONNECTOR_Unknown)
>  		return ERR_PTR(-EINVAL);

Is there a missing dereference on connector_type here?

Since connector_type is now an int pointer and DRM_MODE_CONNECTOR_Unknown
is 0, this evaluates as a NULL pointer check rather than checking the
value. 

Because the address of a stack variable is passed to the function, the
pointer is never NULL, so this check will always fail and bypass the error
return.

Should this be checking *connector_type instead?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260519-drm-bridge-hotplug-v1-0-45e2bdb3dfb4@bootlin.com?part=7