Commit 8238ee93 authored Sep 02, 2020 by Al Viro Committed by Greg Kroah-Hartman Sep 12, 2020

fix regression in "epoll: Keep a reference on files added to the check list"



[ Upstream commit 77f4689de17c0887775bb77896f4cc11a39bf848 ]

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 <maz@kernel.org>
Fixes: a9ed4a6560b8 ("epoll: Keep a reference on files added to the check list")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent ba13c07c

fs/eventpoll.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -1748,7 +1748,7 @@ 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);
		if (get_file_rcu(epi->ffd.file))
		list_add(&epi->ffd.file->f_tfile_llink,
		&tfile_check_list);
		}