diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index d057bc29bf4c..b84ef2295d4f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1010,6 +1010,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
 
 	if (gtt && gtt->userptr) {
 		kfree(ttm->sg);
+		ttm->sg = NULL;
 		ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
 		return;
 	}