From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39410 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934199AbcI0PFB (ORCPT ); Tue, 27 Sep 2016 11:05:01 -0400 Subject: Patch "cgroup: duplicate cgroup reference when cloning sockets" has been added to the 4.7-stable tree To: jweiner@fb.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, hannes@cmpxchg.org, mhocko@suse.cz, tj@kernel.org, torvalds@linux-foundation.org, vdavydov@virtuozzo.com Cc: , From: Date: Tue, 27 Sep 2016 17:04:42 +0200 Message-ID: <147498868287174@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled cgroup: duplicate cgroup reference when cloning sockets to the 4.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cgroup-duplicate-cgroup-reference-when-cloning-sockets.patch and it can be found in the queue-4.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d979a39d7242e0601bf9b60e89628fb8ac577179 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Mon, 19 Sep 2016 14:44:38 -0700 Subject: cgroup: duplicate cgroup reference when cloning sockets From: Johannes Weiner commit d979a39d7242e0601bf9b60e89628fb8ac577179 upstream. When a socket is cloned, the associated sock_cgroup_data is duplicated but not its reference on the cgroup. As a result, the cgroup reference count will underflow when both sockets are destroyed later on. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Link: http://lkml.kernel.org/r/20160914194846.11153-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Acked-by: Tejun Heo Cc: Michal Hocko Cc: Vladimir Davydov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/cgroup.c | 6 ++++++ net/core/sock.c | 5 ++++- 2 files changed, 10 insertions(+), 1 deletion(-) --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -6240,6 +6240,12 @@ void cgroup_sk_alloc(struct sock_cgroup_ if (cgroup_sk_alloc_disabled) return; + /* Socket clone path */ + if (skcd->val) { + cgroup_get(sock_cgroup_ptr(skcd)); + return; + } + rcu_read_lock(); while (true) { --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1362,7 +1362,6 @@ static struct sock *sk_prot_alloc(struct if (!try_module_get(prot->owner)) goto out_free_sec; sk_tx_queue_clear(sk); - cgroup_sk_alloc(&sk->sk_cgrp_data); } return sk; @@ -1422,6 +1421,7 @@ struct sock *sk_alloc(struct net *net, i sock_net_set(sk, net); atomic_set(&sk->sk_wmem_alloc, 1); + cgroup_sk_alloc(&sk->sk_cgrp_data); sock_update_classid(&sk->sk_cgrp_data); sock_update_netprioidx(&sk->sk_cgrp_data); } @@ -1566,6 +1566,9 @@ struct sock *sk_clone_lock(const struct newsk->sk_priority = 0; newsk->sk_incoming_cpu = raw_smp_processor_id(); atomic64_set(&newsk->sk_cookie, 0); + + cgroup_sk_alloc(&newsk->sk_cgrp_data); + /* * Before updating sk_refcnt, we must commit prior changes to memory * (Documentation/RCU/rculist_nulls.txt for details) Patches currently in stable-queue which might be from jweiner@fb.com are queue-4.7/mm-memcontrol-make-per-cpu-charge-cache-irq-safe-for-socket-accounting.patch queue-4.7/cgroup-duplicate-cgroup-reference-when-cloning-sockets.patch