--- a/sys/dev/drm/drm_gem.c
+++ b/sys/dev/drm/drm_gem.c
@@ -582,8 +585,20 @@
 	}
 	obj->on_map = true;
 
-	return drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
-				  size / PAGE_SIZE);
+	ret = drm_vma_offset_add(dev->vma_offset_manager, &obj->vma_node,
+				 size / PAGE_SIZE);
+	if (ret != 0) {
+		/*
+		 * Undo the hash/unr publication so obj state stays
+		 * consistent (on_map false again) and a later retry
+		 * starts clean instead of returning "success" with no
+		 * vma offset allocated and a leaked idx.
+		 */
+		drm_ht_remove_item(&mm->offset_hash, &obj->map_list);
+		free_unr(mm->idxunr, obj->map_list.key);
+		obj->on_map = false;
+	}
+	return (ret);
 }
 EXPORT_SYMBOL(drm_gem_create_mmap_offset_size);