From: jsg <jsg@openbsd.org>
Date: Thu, 25 Aug 2022 23:49:31 +0000 (+0000)
Subject: drm/ttm: Fix dummy res NULL ptr deref bug
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=a8f13b42dbdfaa4e533ffce1995f3feee788619c;p=openbsd

drm/ttm: Fix dummy res NULL ptr deref bug

From Arunpravin Paneer Selvam
76672cd326c146ded2c2712ff257b8908dcf23d8 in linux 5.15.y/5.15.63
cf4b7387c0a842d64bdd7c353e6d3298174a7740 in mainline linux
---

diff --git a/sys/dev/pci/drm/ttm/ttm_bo.c b/sys/dev/pci/drm/ttm/ttm_bo.c
index d66b8341081..81d9aeafec8 100644
--- a/sys/dev/pci/drm/ttm/ttm_bo.c
+++ b/sys/dev/pci/drm/ttm/ttm_bo.c
@@ -987,7 +987,7 @@ int ttm_bo_validate(struct ttm_buffer_object *bo,
 	/*
 	 * We might need to add a TTM.
 	 */
-	if (bo->resource->mem_type == TTM_PL_SYSTEM) {
+	if (!bo->resource || bo->resource->mem_type == TTM_PL_SYSTEM) {
 		ret = ttm_tt_create(bo, true);
 		if (ret)
 			return ret;