drm: bridge/panel: Cleanup connector on bridge detach

Vulnerability Description

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

References

• https://git.kernel.org/stable/c/ce450934a00cf896e648fde08d0bd1426653d7a2
• https://git.kernel.org/stable/c/18149b420c9bd93c443e8d1f48a063d71d9f6aa1
• https://git.kernel.org/stable/c/98d7d76a74e48ec3ddf2e23950adff7edcab9327
• https://git.kernel.org/stable/c/4d906839d321c2efbf3fed4bc31ffd9ff55b75c0