From a28bf136e651e17d7e2c753aa140ce3cc1df36a0 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 30 Mar 2020 16:33:39 -0500 Subject: [PATCH] exec: Run sync_mm_rss before taking exec_update_mutex Like exec_mm_release sync_mm_rss is about flushing out the state of the old_mm, which does not need to happen under exec_update_mutex. Make this explicit by moving sync_mm_rss outside of exec_update_mutex. Reviewed-by: Kees Cook Link: https://lkml.kernel.org/r/875zd66za3.fsf_-_@x220.int.ebiederm.org Signed-off-by: "Eric W. Biederman" --- fs/exec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/exec.c b/fs/exec.c index 82106241ed53..ecee0ebebf85 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1051,13 +1051,14 @@ static int exec_mmap(struct mm_struct *mm) tsk = current; old_mm = current->mm; exec_mm_release(tsk, old_mm); + if (old_mm) + sync_mm_rss(old_mm); ret = mutex_lock_killable(&tsk->signal->exec_update_mutex); if (ret) return ret; if (old_mm) { - sync_mm_rss(old_mm); /* * Make sure that if there is a core dump in progress * for the old mm, we get out and die instead of going