Commit b18398c1 authored by Boris Brezillon's avatar Boris Brezillon
Browse files

drm/bridge: Fix a NULL pointer dereference in drm_atomic_bridge_chain_check() 



drm_atomic_bridge_chain_check() callers can pass a NULL bridge. Let's
bail out before dereferencing the bridge pointer when that happens.

Reported-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Fixes: b86d8955 ("drm/bridge: Add an ->atomic_check() hook")
Signed-off-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107113031.435604-1-boris.brezillon@collabora.com
parent 3cacb208

drivers/gpu/drm/drm_bridge.c

+5 −1
Original line number Diff line number Diff line
@@ -938,15 +938,19 @@ int drm_atomic_bridge_chain_check(struct drm_bridge *bridge, 
				  struct drm_connector_state *conn_state)

{

	struct drm_connector *conn = conn_state->connector;

	struct drm_encoder *encoder = bridge->encoder;

	struct drm_encoder *encoder;

	struct drm_bridge *iter;

	int ret;



	if (!bridge)

		return 0;



	ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,

						      conn_state);

	if (ret)

		return ret;



	encoder = bridge->encoder;

	list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {

		int ret;

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