From patchwork Wed Apr 14 16:12:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Westphal X-Patchwork-Id: 421562 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1A3BC433B4 for ; Wed, 14 Apr 2021 16:13:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FC5B61168 for ; Wed, 14 Apr 2021 16:13:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351603AbhDNQNi (ORCPT ); Wed, 14 Apr 2021 12:13:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351591AbhDNQNh (ORCPT ); Wed, 14 Apr 2021 12:13:37 -0400 Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:12e:520::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 40E76C061574 for ; Wed, 14 Apr 2021 09:13:16 -0700 (PDT) Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92) (envelope-from ) id 1lWi8g-0005rm-Uc; Wed, 14 Apr 2021 18:13:14 +0200 From: Florian Westphal To: Cc: steffen.klassert@secunet.com, davem@davemloft.net, kuba@kernel.org, herbert@gondor.apana.org.au, Florian Westphal Subject: [PATCH ipsec-next 3/3] xfrm: avoid synchronize_rcu during netns destruction Date: Wed, 14 Apr 2021 18:12:53 +0200 Message-Id: <20210414161253.27586-4-fw@strlen.de> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210414161253.27586-1-fw@strlen.de> References: <20210414161253.27586-1-fw@strlen.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use the new exit_pre hook to NULL the netlink socket. The net namespace core will do a synchronize_rcu() between the exit_pre and exit/exit_batch handlers. Signed-off-by: Florian Westphal --- net/xfrm/xfrm_user.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 5a0ef4361e43..9313592fa01f 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -3480,18 +3480,22 @@ static int __net_init xfrm_user_net_init(struct net *net) return 0; } +static void __net_exit xfrm_user_net_pre_exit(struct net *net) +{ + RCU_INIT_POINTER(net->xfrm.nlsk, NULL); +} + static void __net_exit xfrm_user_net_exit(struct list_head *net_exit_list) { struct net *net; - list_for_each_entry(net, net_exit_list, exit_list) - RCU_INIT_POINTER(net->xfrm.nlsk, NULL); - synchronize_net(); + list_for_each_entry(net, net_exit_list, exit_list) netlink_kernel_release(net->xfrm.nlsk_stash); } static struct pernet_operations xfrm_user_net_ops = { .init = xfrm_user_net_init, + .pre_exit = xfrm_user_net_pre_exit, .exit_batch = xfrm_user_net_exit, };