[PATCH stable-4.19] cgroup: add missing skcd->no_refcnt check in cgroup_sk_clone()

From: Yang Yingliang
Date: Thu Aug 13 2020 - 08:35:55 EST


Add skcd->no_refcnt check which is missed when backporting
ad0f75e5f57c ("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@xxxxxxxxxx>
---
kernel/cgroup/cgroup.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 6ae98c714edd..2a879d34bbe5 100644
--- 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.
--
2.25.1