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 4CEA4C04A68 for ; Wed, 27 Jul 2022 16:51:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240711AbiG0QvX (ORCPT ); Wed, 27 Jul 2022 12:51:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55560 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240717AbiG0Quu (ORCPT ); Wed, 27 Jul 2022 12:50:50 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6419061D8F; Wed, 27 Jul 2022 09:33:14 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 35B9A61A24; Wed, 27 Jul 2022 16:33:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43205C433C1; Wed, 27 Jul 2022 16:33:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939592; bh=oLuofaZzXhRDN7d9d6KpMVZa4bYXqOlIP0G4Leb4uJc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n/243BHaAqGMjjc8/0mbnSSCrwGtKmBhGeovJ2LVpFb+mgsmleCQ4MK0cCuBb1tg1 L9EVF6jQvMOv/rfEdm1pZMnr2i/Iye8a/r2vOMBOnonrP3m2IUAMeg6bbDpRnq1l58 i4AKdmt9wB+Pl52Q4zaPztlxepAWNlwXaI1MU0RU= 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 5.10 036/105] tcp: Fix data-races around sysctl_tcp_base_mss. Date: Wed, 27 Jul 2022 18:10:22 +0200 Message-Id: <20220727161013.550990320@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 88d78bc097cd8ebc6541e93316c9d9bf651b13e8 ] While reading sysctl_tcp_base_mss, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 5d424d5a674f ("[TCP]: MTU probing") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_output.c | 2 +- net/ipv4/tcp_timer.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 423ec09ad831..9f3eec8e7e4c 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1766,7 +1766,7 @@ void tcp_mtup_init(struct sock *sk) icsk->icsk_mtup.enabled = READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing) > 1; icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) + icsk->icsk_af_ops->net_header_len; - icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, net->ipv4.sysctl_tcp_base_mss); + icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, READ_ONCE(net->ipv4.sysctl_tcp_base_mss)); icsk->icsk_mtup.probe_size = 0; if (icsk->icsk_mtup.enabled) icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 3c0d689cafac..795716fd3761 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -171,7 +171,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; } else { mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1; - mss = min(net->ipv4.sysctl_tcp_base_mss, mss); + mss = min(READ_ONCE(net->ipv4.sysctl_tcp_base_mss), mss); mss = max(mss, net->ipv4.sysctl_tcp_mtu_probe_floor); mss = max(mss, net->ipv4.sysctl_tcp_min_snd_mss); icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); -- 2.35.1