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 7C471C19F28 for ; Wed, 27 Jul 2022 16:44:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235821AbiG0Qoo (ORCPT ); Wed, 27 Jul 2022 12:44:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239879AbiG0Qnn (ORCPT ); Wed, 27 Jul 2022 12:43:43 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDD255D0E3; Wed, 27 Jul 2022 09:30:33 -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 6BC5761A55; Wed, 27 Jul 2022 16:30:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48F53C433D6; Wed, 27 Jul 2022 16:30:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939423; bh=jN76glgLg76fpSC8BmLDBgVCmpV2XuZmWzCxAT1uP3s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S+2GjVnB3ZmXL7LYcP/JmXAjeQ6VbImu4qgCR0Em1UW+myATaUtAlMrIErXCrvdeA knB6QypRXiPTf55a52PSArsdvgb2ZVy7xYPhHXbcDvRTCJYWQvw8G/2YcjcfpHqANn MM7BOesgd75JsayUc2dIa4JWVO7b6/kP1Tm0QnSg= 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 47/87] tcp: Fix a data-race around sysctl_tcp_early_retrans. Date: Wed, 27 Jul 2022 18:10:40 +0200 Message-Id: <20220727161010.956863929@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 52e65865deb6a36718a463030500f16530eaab74 ] While reading sysctl_tcp_early_retrans, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: eed530b6c676 ("tcp: early retransmit") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5cc345c4006e..72ee1fca0501 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2509,7 +2509,7 @@ bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto) if (rcu_access_pointer(tp->fastopen_rsk)) return false; - early_retrans = sock_net(sk)->ipv4.sysctl_tcp_early_retrans; + early_retrans = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_early_retrans); /* Schedule a loss probe in 2*RTT for SACK capable connections * not in loss recovery, that are either limited by cwnd or application. */ -- 2.35.1