From nobody Fri Dec 19 07:47:28 2025 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 320E1C00144 for ; Mon, 1 Aug 2022 12:04:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232953AbiHAMEQ (ORCPT ); Mon, 1 Aug 2022 08:04:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232777AbiHAMCb (ORCPT ); Mon, 1 Aug 2022 08:02:31 -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 5E80E54CA3; Mon, 1 Aug 2022 04:54:01 -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 70E75B80E8F; Mon, 1 Aug 2022 11:54:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1D2AC433D7; Mon, 1 Aug 2022 11:53:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354839; bh=iK4b8g/7nH1wBTsDaWuZzdBFa+OXGbijtK8FFi9mvZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1z8qlOWHKEc9PfRT+U7Klyn6uHF2wYKcJQng2ny2kESjxRx05wE3G6k3KAqPku4BI bvhLUPRSppbW3wW6HHPkYvcndwzsXM5uLPctAfml2eZhjCRNA/cJDt4o+Pf1pvqVan BvWVx18axiHlHZ1iF9U9pYZUb8D2v9Ec7zybQfDI= 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 37/69] tcp: Fix a data-race around sysctl_tcp_min_rtt_wlen. Date: Mon, 1 Aug 2022 13:47:01 +0200 Message-Id: <20220801114135.995249238@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114134.468284027@linuxfoundation.org> References: <20220801114134.468284027@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Kuniyuki Iwashima [ Upstream commit 1330ffacd05fc9ac4159d19286ce119e22450ed2 ] While reading sysctl_tcp_min_rtt_wlen, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: f672258391b4 ("tcp: track min RTT using windowed min-filter") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a5357ebfbcc0..b925c766f1d2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3050,7 +3050,7 @@ static void tcp_fastretrans_alert(struct sock *sk, co= nst u32 prior_snd_una, =20 static void tcp_update_rtt_min(struct sock *sk, u32 rtt_us, const int flag) { - u32 wlen =3D sock_net(sk)->ipv4.sysctl_tcp_min_rtt_wlen * HZ; + u32 wlen =3D READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_rtt_wlen) * HZ; struct tcp_sock *tp =3D tcp_sk(sk); =20 if ((flag & FLAG_ACK_MAYBE_DELAYED) && rtt_us > tcp_min_rtt(tp)) { --=20 2.35.1