This is a note to let you know that I've just added the patch titled drm: bridge/panel: Cleanup connector on bridge detach to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-bridge-panel-cleanup-connector-on-bridge-detach.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4d906839d321c2efbf3fed4bc31ffd9ff55b75c0 Mon Sep 17 00:00:00 2001 From: Paul Cercueil <paul@xxxxxxxxxxxxxxx> Date: Sat, 27 Mar 2021 11:57:40 +0000 Subject: drm: bridge/panel: Cleanup connector on bridge detach From: Paul Cercueil <paul@xxxxxxxxxxxxxxx> commit 4d906839d321c2efbf3fed4bc31ffd9ff55b75c0 upstream. 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 Fixes: 13dfc0540a57 ("drm/bridge: Refactor out the panel wrapper from the lvds-encoder bridge.") Cc: <stable@xxxxxxxxxxxxxxx> # 4.12+ Cc: Andrzej Hajda <a.hajda@xxxxxxxxxxx> Cc: Neil Armstrong <narmstrong@xxxxxxxxxxxx> Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx> Cc: Jonas Karlman <jonas@xxxxxxxxx> Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxx> Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210327115742.18986-2-paul@xxxxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/panel.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/gpu/drm/bridge/panel.c +++ b/drivers/gpu/drm/bridge/panel.c @@ -87,6 +87,18 @@ static int panel_bridge_attach(struct dr static void panel_bridge_detach(struct drm_bridge *bridge) { + struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); + struct drm_connector *connector = &panel_bridge->connector; + + /* + * Cleanup the connector if we know it was initialized. + * + * FIXME: This wouldn't be needed if the panel_bridge structure was + * allocated with drmm_kzalloc(). This might be tricky since the + * drm_device pointer can only be retrieved when the bridge is attached. + */ + if (connector->dev) + drm_connector_cleanup(connector); } static void panel_bridge_pre_enable(struct drm_bridge *bridge) Patches currently in stable-queue which might be from paul@xxxxxxxxxxxxxxx are queue-5.10/drm-bridge-panel-cleanup-connector-on-bridge-detach.patch