CVE-2021-47063

In the Linux kernel, the following vulnerability has been resolved: drm:
bridge/panel: Cleanup connector on bridge detach If we don’t call
drm_connector_cleanup() manually in panel_bridge_detach(), the connector
will be cleaned up with the other DRM objects in the call to
drm_mode_config_cleanup(). However, since our drm_connector is
devm-allocated, by the time drm_mode_config_cleanup() will be called, our
connector will be long gone. Therefore, the connector must be cleaned up
when the bridge is detached to avoid use-after-free conditions. v2: Cleanup
connector only if it was created v3: Add FIXME v4: (Use connector->dev)
directly in if() block