Which testcase do you execute ？ backup_malloc.test or mallocAll.test ? If only execute backup_malloc.test, it wolud be ok because it doesn't check that fd is closed. If not encounter OOM situations in the backup_malloc.test, the testcase also is ok, But the fd is not closed, it would affect the result of other testcases, such as malloc.test malloc-1.X etc. if so, the relation of tesecases exists coupling. This scenario is also right ？