diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index a7bab87..d940c82 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -547,12 +547,17 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
 	} else
 		swap_storage = persistant_swap_storage;
 
+	BUG_ON(swap_storage == NULL);
+	BUG_ON(swap_storage->f_path.dentry == NULL);
+	BUG_ON(swap_storage->f_path.dentry->d_inode == NULL);
+
 	swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
 
 	for (i = 0; i < ttm->num_pages; ++i) {
 		from_page = ttm->pages[i];
 		if (unlikely(from_page == NULL))
 			continue;
+		BUG_ON(swap_space == NULL);
 		to_page = read_mapping_page(swap_space, i, NULL);
 		if (unlikely(IS_ERR(to_page))) {
 			ret = PTR_ERR(to_page);