From e131e029bdcfba828dc8f8554d2470aabf62af54 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 2 Sep 2020 11:30:48 -0400 Subject: [PATCH] fix regression in "epoll: Keep a reference on files added to the check list" epoll_loop_check_proc() can run into a file already committed to destruction; we can't grab a reference on those and don't need to add them to the set for reverse path check anyway. Tested-by: Marc Zyngier Fixes: f581d9774cca ("epoll: Keep a reference on files added to the check list") Signed-off-by: Al Viro --- fs/eventpoll.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/eventpoll.c b/fs/eventpoll.c index e0decff22ae27..8107e06d7f6f5 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1995,9 +1995,9 @@ static int ep_loop_check_proc(void *priv, void *cookie, int call_nests) * during ep_insert(). */ if (list_empty(&epi->ffd.file->f_tfile_llink)) { - get_file(epi->ffd.file); - list_add(&epi->ffd.file->f_tfile_llink, - &tfile_check_list); + if (get_file_rcu(epi->ffd.file)) + list_add(&epi->ffd.file->f_tfile_llink, + &tfile_check_list); } } } -- 2.39.5