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 16184C04A68 for ; Wed, 27 Jul 2022 16:45:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239570AbiG0Qpb (ORCPT ); Wed, 27 Jul 2022 12:45:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240280AbiG0QoP (ORCPT ); Wed, 27 Jul 2022 12:44:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E8CB2DB; Wed, 27 Jul 2022 09:30:57 -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 9F9C4B821C5; Wed, 27 Jul 2022 16:30:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14304C433C1; Wed, 27 Jul 2022 16:30:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939454; bh=ogdpYql1/PZgtWlueFCk1S1UTn53QIdYTmXoyTpukf8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q/4e14jTmVgM8oCBFtIIpPZOc+Lpnb8W+w9OFdDgJ5P4jKOlR/a+Bw0qrHdiA512V kAFcgnNb/5lCBKCoeol7iBeHo0zYrNBD2bV/SXywgWJoBOh7gdfg8yUMwyBhBbkxki AcTxzv1x/r2La2tvdoBiYwvu5RmLIA32MuY5SL4A= 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 48/87] tcp: Fix data-races around sysctl_tcp_recovery. Date: Wed, 27 Jul 2022 18:10:41 +0200 Message-Id: <20220727161010.995412934@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 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 28df6c3feb3f..2f57c365ebd5 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1950,7 +1950,8 @@ 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 8757bb6cb1d9..22ec8dcc1428 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; } @@ -204,7 +205,8 @@ 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