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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1460C04A68 for ; Wed, 27 Jul 2022 16:41:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239418AbiG0QlM (ORCPT ); Wed, 27 Jul 2022 12:41:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238535AbiG0Qke (ORCPT ); Wed, 27 Jul 2022 12:40:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A255501A1; Wed, 27 Jul 2022 09:29:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DFCE7B821B7; Wed, 27 Jul 2022 16:29:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 530B5C433C1; Wed, 27 Jul 2022 16:29:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939344; bh=/ciaY/hwux9z8FoKIievm1p7/Dd8DlPPouRdBKJ9vhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SgM7g5ysa4C2j55KWwUbJlmLGQYQ/cLULGQmgSrJJqzzUEJgH44ukp1RiViWP5Ft8 Qwh0nGmLfFSm9pREJprKZeD5HQ2MPW8h2oYcRBpLJSWIsvemjZ33G6iAQKRm6hV0tl fdlG4WhWYxjQO+yGq2oc5PUGqUNmzODwcHq8DgcY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 36/87] tcp: Fix a data-race around sysctl_tcp_tw_reuse. Date: Wed, 27 Jul 2022 18:10:29 +0200 Message-Id: <20220727161010.514233407@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161008.993711844@linuxfoundation.org> References: <20220727161008.993711844@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit cbfc6495586a3f09f6f07d9fb3c7cafe807e3c55 ] While reading sysctl_tcp_tw_reuse, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_ipv4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 72fe93ace7d7..b95e1a3487c8 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -105,10 +105,10 @@ static u32 tcp_v4_init_ts_off(const struct net *net, const struct sk_buff *skb) int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp) { + int reuse = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_tw_reuse); const struct inet_timewait_sock *tw = inet_twsk(sktw); const struct tcp_timewait_sock *tcptw = tcp_twsk(sktw); struct tcp_sock *tp = tcp_sk(sk); - int reuse = sock_net(sk)->ipv4.sysctl_tcp_tw_reuse; if (reuse == 2) { /* Still does not detect *everything* that goes through -- 2.35.1