From mboxrd@z Thu Jan 1 00:00:00 1970 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 26453C432C0 for ; Fri, 22 Nov 2019 06:20:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED59C2068E for ; Fri, 22 Nov 2019 06:20:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574403633; bh=ePJ2pkZNK2a4mQjfJXGV5Pv+SMUz7DMtBlOvjCi1n7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UT7t2D1KXpBgM+RXEgoJvowRxupSr65xu/STb3WiVaTyF9XEohZatS07CAdgnxj1X kK8l3RAUQgaGpKemC49JwN7X6W5jlwA73ek7Lq+ZW92/16EJoe83zeHjxd/RfTJPxn OFGxI15QDKa70pFjEK3+P4Rjxq6LQ22nOUpJhqKo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728631AbfKVFwj (ORCPT ); Fri, 22 Nov 2019 00:52:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:58454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728617AbfKVFwj (ORCPT ); Fri, 22 Nov 2019 00:52:39 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5D4A72071F; Fri, 22 Nov 2019 05:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574401958; bh=ePJ2pkZNK2a4mQjfJXGV5Pv+SMUz7DMtBlOvjCi1n7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C7n3M9KkLNHLdJa8OmwOGM/laX+CcSrKZd1jVNAPUS4ajQAfwMc+Hzu8Va3HQLvDf /PXEPVDDaLssgvxK7SUo9WfhaNs079fX6z8r364+Q32J02pv3qBpfw8/SmJnXGSzNR U6u9jkdT7lwcYzxq0381bFfd5kBHXEnnckY5nn00= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Karsten Graul , Ursula Braun , "David S . Miller" , Sasha Levin , linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 180/219] net/smc: prevent races between smc_lgr_terminate() and smc_conn_free() Date: Fri, 22 Nov 2019 00:48:32 -0500 Message-Id: <20191122054911.1750-173-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122054911.1750-1-sashal@kernel.org> References: <20191122054911.1750-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Karsten Graul [ Upstream commit 77f838ace755d2f466536c44dac6c856f62cd901 ] To prevent races between smc_lgr_terminate() and smc_conn_free() add an extra check of the lgr field before accessing it, and cancel a delayed free_work when a new smc connection is created. This fixes the problem that free_work cleared the lgr variable but smc_lgr_terminate() or smc_conn_free() still access it in parallel. Signed-off-by: Karsten Graul Signed-off-by: Ursula Braun Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/smc/smc_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 18daebcef1813..2c9baf8bf1189 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -128,6 +128,8 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn) { struct smc_link_group *lgr = conn->lgr; + if (!lgr) + return; write_lock_bh(&lgr->conns_lock); if (conn->alert_token_local) { __smc_lgr_unregister_conn(conn); @@ -612,6 +614,8 @@ int smc_conn_create(struct smc_sock *smc, bool is_smcd, int srv_first_contact, local_contact = SMC_REUSE_CONTACT; conn->lgr = lgr; smc_lgr_register_conn(conn); /* add smc conn to lgr */ + if (delayed_work_pending(&lgr->free_work)) + cancel_delayed_work(&lgr->free_work); write_unlock_bh(&lgr->conns_lock); break; } -- 2.20.1