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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 8EA54C432C3 for ; Tue, 3 Dec 2019 23:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 527AA20656 for ; Tue, 3 Dec 2019 23:02:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575414147; bh=ePJ2pkZNK2a4mQjfJXGV5Pv+SMUz7DMtBlOvjCi1n7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OZodbCXFYfkXMLQ6F16uSo4SOpvrEvrzRUsozFqTJVdEizhoL+TcsIoDn0zs2r3UT QPmBbLUhWoLyT77UBwutaVRndck54NzvCSfPp9oPZYEKp0zO2h+Pm7yov5IC63iXNI pk2tTopzBESyqZ65NXH08CfV5ae86FB0QTLRGvMc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730650AbfLCXCZ (ORCPT ); Tue, 3 Dec 2019 18:02:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:48798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728821AbfLCWyr (ORCPT ); Tue, 3 Dec 2019 17:54:47 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A7AD820803; Tue, 3 Dec 2019 22:54:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575413686; bh=ePJ2pkZNK2a4mQjfJXGV5Pv+SMUz7DMtBlOvjCi1n7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H8CtXLbuNxrHiVOZuLAfXfTlblfxxOBurNXC9cfOLHdCWtt+NpcKIzs5G8rrZkZ/y 0y1Je7h8MgEEvU6c2YDWoSvICr7CwoFjn+V/ZhasQRKLZ3Y4OE22qQMwj8khdQOV6p hJT/5hjRQRAzo7jmqxDb9qIvk0YQ3yrxyKX6z1RI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Karsten Graul , Ursula Braun , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 224/321] net/smc: prevent races between smc_lgr_terminate() and smc_conn_free() Date: Tue, 3 Dec 2019 23:34:50 +0100 Message-Id: <20191203223438.769639679@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191203223427.103571230@linuxfoundation.org> References: <20191203223427.103571230@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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