drm/core: Fix ordering in drm_mode_config_cleanup.

__drm_atomic_helper_plane_destroy_state calls
drm_framebuffer_unreference, which means that if drm_framebuffer_free
is called before plane->destroy freed memory will be accessed.

A similar case happens for the blob list, which was freed before the
crtc state was, resulting in the unreference_blob from crtc_destroy_state
pointing to garbage memory causing another opportunity for a GPF.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458657734-21866-1-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/drm_crtc.c

@@ -5914,6 +5914,15 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 		drm_property_destroy(dev, property);
 	}
 
+	list_for_each_entry_safe(plane, plt, &dev->mode_config.plane_list,
+				 head) {
+		plane->funcs->destroy(plane);
+	}
+
+	list_for_each_entry_safe(crtc, ct, &dev->mode_config.crtc_list, head) {
+		crtc->funcs->destroy(crtc);
+	}
+
 	list_for_each_entry_safe(blob, bt, &dev->mode_config.property_blob_list,
 				 head_global) {
 		drm_property_unreference_blob(blob);
@@ -5932,15 +5941,6 @@ void drm_mode_config_cleanup(struct drm_device *dev)
 		drm_framebuffer_free(&fb->refcount);
 	}
 
-	list_for_each_entry_safe(plane, plt, &dev->mode_config.plane_list,
-				 head) {
-		plane->funcs->destroy(plane);
-	}
-
-	list_for_each_entry_safe(crtc, ct, &dev->mode_config.crtc_list, head) {
-		crtc->funcs->destroy(crtc);
-	}
-
 	ida_destroy(&dev->mode_config.connector_ida);
 	idr_destroy(&dev->mode_config.tile_idr);
 	idr_destroy(&dev->mode_config.crtc_idr);