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 483D9C04A68 for ; Wed, 27 Jul 2022 16:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237846AbiG0Qc2 (ORCPT ); Wed, 27 Jul 2022 12:32:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235592AbiG0QcA (ORCPT ); Wed, 27 Jul 2022 12:32:00 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBD6652FCB; Wed, 27 Jul 2022 09:25:58 -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 0007FB821BF; Wed, 27 Jul 2022 16:25:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58435C43140; Wed, 27 Jul 2022 16:25:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939136; bh=Ah/hhKtg8RhQI3Os/uogsJTfd+tyUxBuQgNvDHm/FgY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zJx3f9KzrxlNlWUdTEz5KF4YsKO9vnmm/5qIDESWgL7TvPaFvCg6oMqPKliLUIF2K Tu8tzwJ2O7pi1ui5JroK/z9ru4m+3jjr0yuiHXQZXGrze4cGSwtD3XwY4YZ98QDgAh npXrqa2PGTB9IILcth6jAywkMj0velmPR/wT/itE= 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 4.19 26/62] tcp: Fix data-races around sysctl_tcp_recovery. Date: Wed, 27 Jul 2022 18:10:35 +0200 Message-Id: <20220727161005.221488139@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161004.175638564@linuxfoundation.org> References: <20220727161004.175638564@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 e7d2ef837e14a971a05f60ea08c47f3fed1a36e4 ] While reading sysctl_tcp_recovery, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 4f41b1c58a32 ("tcp: use RACK to detect losses") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 3 ++- net/ipv4/tcp_recovery.c | 6 ++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index afe195e03a95..731c4d220905 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1938,7 +1938,8 @@ static inline void tcp_init_undo(struct tcp_sock *tp) static bool tcp_is_rack(const struct sock *sk) { - return sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_LOSS_DETECTION; + return READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_LOSS_DETECTION; } /* If we detect SACK reneging, forget all SACK information diff --git a/net/ipv4/tcp_recovery.c b/net/ipv4/tcp_recovery.c index 0d96decba13d..61969bb9395c 100644 --- a/net/ipv4/tcp_recovery.c +++ b/net/ipv4/tcp_recovery.c @@ -33,7 +33,8 @@ static u32 tcp_rack_reo_wnd(const struct sock *sk) return 0; if (tp->sacked_out >= tp->reordering && - !(sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_NO_DUPTHRESH)) + !(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_NO_DUPTHRESH)) return 0; } @@ -203,7 +204,8 @@ void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs) { struct tcp_sock *tp = tcp_sk(sk); - if (sock_net(sk)->ipv4.sysctl_tcp_recovery & TCP_RACK_STATIC_REO_WND || + if ((READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_recovery) & + TCP_RACK_STATIC_REO_WND) || !rs->prior_delivered) return; -- 2.35.1