cgroup: add missing skcd->no_refcnt check in cgroup_sk_clone()

Yang Yingliang · gregkh · commit 38de4308c5c3 · 2020-08-19T08:14:47.000+02:00
Add skcd->no_refcnt check which is missed when backporting ad0f75e ("cgroup: fix cgroup_sk_alloc() for sk_clone_lock()"). This patch is needed in stable-4.9, stable-4.14 and stable-4.19. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
@@ -5957,6 +5957,8 @@ void cgroup_sk_clone(struct sock_cgroup_data *skcd)
 {
 	/* Socket clone path */
 	if (skcd->val) {
+		if (skcd->no_refcnt)
+			return;
 		/*
 		 * We might be cloning a socket which is left in an empty
 		 * cgroup and the cgroup might have already been rmdir'd.

Original file line number	Diff line number	Diff line change
`@@ -5957,6 +5957,8 @@ void cgroup_sk_clone(struct sock_cgroup_data *skcd)`
`5957`	`5957`	`{`
`5958`	`5958`	`/* Socket clone path */`
`5959`	`5959`	`if (skcd->val) {`
	`5960`	`+ if (skcd->no_refcnt)`
	`5961`	`+ return;`
`5960`	`5962`	`/*`
`5961`	`5963`	`* We might be cloning a socket which is left in an empty`
`5962`	`5964`	`* cgroup and the cgroup might have already been rmdir'd.`