From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kirill Tkhai Subject: [PATCH RFC 04/25] net: Move mutex_unlock() in cleanup_net() up Date: Fri, 17 Nov 2017 21:27:49 +0300 Message-ID: <151094326992.20009.18255121392857085479.stgit@localhost.localdomain> References: <151094119999.20009.6955267140148739392.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: davem@davemloft.net, vyasevic@redhat.com, kstewart@linuxfoundation.org, pombredanne@nexb.com, vyasevich@gmail.com, mark.rutland@arm.com, gregkh@linuxfoundation.org, adobriyan@gmail.com, fw@strlen.de, nicolas.dichtel@6wind.com, xiyou.wangcong@gmail.com, roman.kapl@sysgo.com, paul@paul-moore.com, dsahern@gmail.com, daniel@iogearbox.net, lucien.xin@gmail.com, mschiffer@universe-factory.net, rshearma@brocade.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, ktkhai@virtuozzo.com, ebiederm@xmission.com, avagin@virtuozzo.com, gorcunov@virtuozzo.com, eric.dumazet@gmail.com, stephen@networkplumber.org, ktkhai@virtuozzo.com Return-path: Received: from mail-eopbgr50102.outbound.protection.outlook.com ([40.107.5.102]:10412 "EHLO EUR03-VE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1760699AbdKQS16 (ORCPT ); Fri, 17 Nov 2017 13:27:58 -0500 In-Reply-To: <151094119999.20009.6955267140148739392.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: net_sem protects from pernet_list changing, while ops_free_list() makes simple kfree(), and it can't race with other pernet_operations callbacks. So we may release net_mutex earlier then it was. Signed-off-by: Kirill Tkhai --- net/core/net_namespace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2254b1639209..a8ea580885d9 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -489,11 +489,12 @@ static void cleanup_net(struct work_struct *work) list_for_each_entry_reverse(ops, &pernet_list, list) ops_exit_list(ops, &net_exit_list); + mutex_unlock(&net_mutex); + /* Free the net generic variables */ list_for_each_entry_reverse(ops, &pernet_list, list) ops_free_list(ops, &net_exit_list); - mutex_unlock(&net_mutex); up_read(&net_sem); /* Ensure there are no outstanding rcu callbacks using this