drm/amd/amdgpu/amdgpu_ttm: Handle return NULL error from ioremap_nocache

Here, If ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.
This error check will avoid NULL pointer dereference.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 10e9b690676e..1154b0a8881d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -548,6 +548,8 @@ static int amdgpu_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_
                         mem->bus.addr =
                                 ioremap_nocache(mem->bus.base + mem->bus.offset,
                                                 mem->bus.size);
+                if (!mem->bus.addr)
+                        return -ENOMEM;
 
                 /*
                  * Alpha: Use just the bus offset plus