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 85AB1C04A68 for ; Wed, 27 Jul 2022 17:07:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238085AbiG0RHM (ORCPT ); Wed, 27 Jul 2022 13:07:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241403AbiG0RGk (ORCPT ); Wed, 27 Jul 2022 13:06:40 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50E7070E65; Wed, 27 Jul 2022 09:39:53 -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 98E2AB821AC; Wed, 27 Jul 2022 16:39:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEEF5C433C1; Wed, 27 Jul 2022 16:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939990; bh=5aJJgCNUDtk8qpGPzgPquBcPXcbJrkVDOJVjGB4GzcQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eYl0sz1saERghcwJEfRxlv5okcSbgQa3iuLpWG4n1c8am2uce4eDcP3hJGIK5doh/ smQsG9eI4JTHLIckmF0I/Vgx0Oe8ZwFNj5COSTMIYEl6TZXdNH+N6UYmR+HCWtxI2J BgzY1SzHJOmEtc8AJgj4V278xGUEbnEc7N9cjCs4= 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 5.15 066/201] tcp: Fix a data-race around sysctl_tcp_mtu_probe_floor. Date: Wed, 27 Jul 2022 18:09:30 +0200 Message-Id: <20220727161029.656239525@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@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 8e92d4423615a5257d0d871fc067aa561f597deb ] While reading sysctl_tcp_mtu_probe_floor, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: c04b79b6cfd7 ("tcp: add new tcp_mtu_probe_floor sysctl") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_timer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 39107bb730b0..4f3b9ab222b6 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -172,7 +172,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) } else { mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1; mss = min(READ_ONCE(net->ipv4.sysctl_tcp_base_mss), mss); - mss = max(mss, net->ipv4.sysctl_tcp_mtu_probe_floor); + mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_mtu_probe_floor)); mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_min_snd_mss)); icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); } -- 2.35.1