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 B17ADC04A68 for ; Wed, 27 Jul 2022 16:39:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238899AbiG0QjC (ORCPT ); Wed, 27 Jul 2022 12:39:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239155AbiG0Qib (ORCPT ); Wed, 27 Jul 2022 12:38:31 -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 472205926B; Wed, 27 Jul 2022 09:28:35 -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 74C4CB821A6; Wed, 27 Jul 2022 16:28:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2F9FC433D6; Wed, 27 Jul 2022 16:28:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939311; bh=8KEZlxPKxQ3tmzEQHpD6PsGQTPZLI4RZcLqnq0HbwFY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U5riwf1hq5AJ5Q5MdZXRf/Uvjw3edFg/AtxU7n4z8lzTwe5huowtNzr4wo+XPW2EX 0UCE3iOVi0s6C3pOqPAR6lc38TiRC/n2cI7Ykr2VSkZ9dTyEvLkSe2e0MurviVKXlK bV5Hmbhenjkzoll/KH0t7WwhgCQxHuQ8kIWkkriQ= 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 25/87] tcp: Fix a data-race around sysctl_tcp_probe_threshold. Date: Wed, 27 Jul 2022 18:10:18 +0200 Message-Id: <20220727161010.055996775@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 92c0aa4175474483d6cf373314343d4e624e882a ] While reading sysctl_tcp_probe_threshold, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 6b58e0a5f32d ("ipv4: Use binary search to choose tcp PMTU probe_size") 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 7c0b96319fc0..e60cb69d00a4 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2134,7 +2134,7 @@ static int tcp_mtu_probe(struct sock *sk) * probing process by not resetting search range to its orignal. */ if (probe_size > tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_high) || - interval < net->ipv4.sysctl_tcp_probe_threshold) { + interval < READ_ONCE(net->ipv4.sysctl_tcp_probe_threshold)) { /* Check whether enough time has elaplased for * another round of probing. */ -- 2.35.1