From 462e00cc7151ed91fba688594436c453c80efb5d Mon Sep 17 00:00:00 2001 From: Ethan Solomita Date: Sun, 15 Jul 2007 23:38:16 -0700 Subject: oom: stop allocating user memory if TIF_MEMDIE is set get_user_pages() can try to allocate a nearly unlimited amount of memory on behalf of a user process, even if that process has been OOM killed. The OOM kill occurs upon return to user space via a SIGKILL, but get_user_pages() will try allocate all its memory before returning. Change get_user_pages() to check for TIF_MEMDIE, and if set then return immediately. Signed-off-by: Ethan Solomita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index ee2925998e2e..cfddcd2075b9 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1055,6 +1055,14 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm, do { struct page *page; + /* + * If tsk is ooming, cut off its access to large memory + * allocations. It has a pending SIGKILL, but it can't + * be processed until returning to user space. + */ + if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE))) + return -ENOMEM; + if (write) foll_flags |= FOLL_WRITE; -- cgit v1.2.3-59-g8ed1b