releases/6.6.3/drm-amdgpu-fix-possible-null-pointer-dereference.patch

From 256503071c2de2b5b5c20e06654aa9a44f13aa62 Mon Sep 17 00:00:00 2001
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Tue, 31 Oct 2023 13:30:00 -0400
Subject: drm/amdgpu: Fix possible null pointer dereference
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From: Felix Kuehling <Felix.Kuehling@amd.com>

commit 256503071c2de2b5b5c20e06654aa9a44f13aa62 upstream.

mem = bo->tbo.resource may be NULL in amdgpu_vm_bo_update.

Fixes: 180253782038 ("drm/ttm: stop allocating dummy resources during BO creation")
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -1095,8 +1095,8 @@ int amdgpu_vm_bo_update(struct amdgpu_de
 				bo = gem_to_amdgpu_bo(gobj);
 		}
 		mem = bo->tbo.resource;
-		if (mem->mem_type == TTM_PL_TT ||
-		    mem->mem_type == AMDGPU_PL_PREEMPT)
+		if (mem && (mem->mem_type == TTM_PL_TT ||
+			    mem->mem_type == AMDGPU_PL_PREEMPT))
 			pages_addr = bo->tbo.ttm->dma_address;
 	}