Unverified Commit 3d9fd0ab authored by Christian Brauner's avatar Christian Brauner
Browse files

eventpoll: use hlist_is_singular_node() in __ep_remove() 

Replace the open-coded "epi is the only entry in file->f_ep" check
with hlist_is_singular_node(). Same semantics, and the helper avoids
the head-cacheline access in the common false case.

Link: https://patch.msgid.link/20260423-work-epoll-uaf-v1-1-2470f9eec0f5@kernel.org


Signed-off-by: default avatarChristian Brauner (Amutable) <brauner@kernel.org>
parent 9a466382

fs/eventpoll.c

+1 −1
Original line number Diff line number Diff line
@@ -856,7 +856,7 @@ static bool __ep_remove(struct eventpoll *ep, struct epitem *epi, bool force) 


	to_free = NULL;

	head = file->f_ep;

	if (head->first == &epi->fllink && !epi->fllink.next) {

	if (hlist_is_singular_node(&epi->fllink, head)) {

		/* See eventpoll_release() for details. */

		WRITE_ONCE(file->f_ep, NULL);

		if (!is_file_epoll(file)) {