Re: [syzbot] [dri?] general protection fault in drm_object_attach_property

[Edward Adam Davis <eadavis@qq.com>]

#syz test

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 11646453aaac..ecbbc967f51f 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2175,8 +2175,12 @@ int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
 	struct drm_property *tv_subconnector;
 	unsigned int i;
 
-	if (dev->mode_config.tv_select_subconnector_property)
+	if (dev->mode_config.tv_select_subconnector_property) {
+		if (num_modes && !dev->mode_config.legacy_tv_mode_property)
+			goto other;
+
 		return 0;
+	}
 
 	/*
 	 * Basic connector properties
@@ -2199,6 +2203,7 @@ int drm_mode_create_tv_properties_legacy(struct drm_device *dev,
 		goto nomem;
 	dev->mode_config.tv_subconnector_property = tv_subconnector;
 
+other:
 	/*
 	 * Other, TV specific properties: margins & TV modes.
 	 */