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 B3DEDC19F28 for ; Wed, 27 Jul 2022 16:55:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240882AbiG0QzM (ORCPT ); Wed, 27 Jul 2022 12:55:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241237AbiG0Qyj (ORCPT ); Wed, 27 Jul 2022 12:54:39 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C4F862A70; Wed, 27 Jul 2022 09:35:47 -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 sin.source.kernel.org (Postfix) with ESMTPS id 4E9D4CE230F; Wed, 27 Jul 2022 16:35:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3CDE3C433C1; Wed, 27 Jul 2022 16:35:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939743; bh=D613NYS3RItS9SkfSXwFD6OJEOqctu9XNqKGGC5B9Ys=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZH4m6NDTrQ9eVE98d1rGva7ZBWNn4gT7UI5l4hGVcc2lkQQ36IpeXASlv8SYQhfce 7RPk4UgKleLgAxgvXSIXTeyQYS0MKdos+QGHAw/voczApAgp0UBocmt9nd40aSWPHr 8YHVpo35FvBlG3hDm4WFr+vZY/c777TQfSFAQqNU= 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 5.10 056/105] tcp: Fix data-races around sysctl_tcp_fastopen_blackhole_timeout. Date: Wed, 27 Jul 2022 18:10:42 +0200 Message-Id: <20220727161014.339107685@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161012.056867467@linuxfoundation.org> References: <20220727161012.056867467@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: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 021266ec640c7a4527e6cd4b7349a512b351de1d ] While reading sysctl_tcp_fastopen_blackhole_timeout, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: cf1ef3f0719b ("net/tcp_fastopen: Disable active side TFO in certain scenarios") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_fastopen.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index ed7aa6ae7b51..39fb037ce5f3 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -506,7 +506,7 @@ void tcp_fastopen_active_disable(struct sock *sk) { struct net *net = sock_net(sk); - if (!sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout) + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout)) return; /* Paired with READ_ONCE() in tcp_fastopen_active_should_disable() */ @@ -527,7 +527,8 @@ void tcp_fastopen_active_disable(struct sock *sk) */ bool tcp_fastopen_active_should_disable(struct sock *sk) { - unsigned int tfo_bh_timeout = sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout; + unsigned int tfo_bh_timeout = + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout); unsigned long timeout; int tfo_da_times; int multiplier; -- 2.35.1