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=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 C15B7C43603 for ; Wed, 4 Dec 2019 18:21:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 980132073B for ; Wed, 4 Dec 2019 18:21:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575483689; bh=8m/MqRha1T/Gf1VwXx+GBM1pGru1K/qiMgwuwyeqJvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rbBDMDQ8nsL2sbu7wOtDp23MDtxswWCTuCPBB6BUuKTw+hLNBopahx6kJ/mBwcHxi BCqvn4bJKdoaYmUc9D3RfljNLbqRreN9r6QY+WY0pXRbtePZWnm+4I9hDBaJbQ+i3o ND2s3H/EP9QwPYDMpxyYiXby3AscFGaekGg+oPDI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729202AbfLDSGj (ORCPT ); Wed, 4 Dec 2019 13:06:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:55268 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729976AbfLDSGi (ORCPT ); Wed, 4 Dec 2019 13:06:38 -0500 Received: from localhost (unknown [217.68.49.72]) (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 68BBA20674; Wed, 4 Dec 2019 18:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482797; bh=8m/MqRha1T/Gf1VwXx+GBM1pGru1K/qiMgwuwyeqJvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RTeOLKVe0+HqPJSgcbGhNLbUrFXOHEF30K8Uej6Pmx60vb7SBXeFlAF1pcUQgXxFI iWMDJd/LJxwLSf6lUrucisA5hrnf5Jx77StnJvp+d03xwQYs28TnsOm/IXLzzCuUhM GIzXeWsqDTU9I+Mr+cgLNjjDYOTEtAHNE7/6r0vo= 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 4.14 136/209] net/smc: prevent races between smc_lgr_terminate() and smc_conn_free() Date: Wed, 4 Dec 2019 18:55:48 +0100 Message-Id: <20191204175332.612859920@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204175321.609072813@linuxfoundation.org> References: <20191204175321.609072813@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 f04a037dc9677..0de788fa43e95 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -103,6 +103,8 @@ static void smc_lgr_unregister_conn(struct smc_connection *conn) struct smc_link_group *lgr = conn->lgr; int reduced = 0; + if (!lgr) + return; write_lock_bh(&lgr->conns_lock); if (conn->alert_token_local) { reduced = 1; @@ -431,6 +433,8 @@ int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr, 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