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 F359AC433EF for ; Wed, 20 Jul 2022 16:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235277AbiGTQxV (ORCPT ); Wed, 20 Jul 2022 12:53:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234516AbiGTQxT (ORCPT ); Wed, 20 Jul 2022 12:53:19 -0400 Received: from smtp-fw-33001.amazon.com (smtp-fw-33001.amazon.com [207.171.190.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC48A68DDE for ; Wed, 20 Jul 2022 09:53:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1658335998; x=1689871998; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Z0ec3b2AXZTvY4943LKhmO/wRh/cB4eXUD//3PNvk1Y=; b=vP90fFwtjcRTVhP2rNP09siBWehyim1SOL0VodHug69uQEgsLX8bpDDV HoC9mE5xzpd/8iMedFxjRTV/wotv/QZC9/IRJVc+FXKoQRBQyJ1gzL7DR dauXZ5g+bToaCK74oV8S4cstAqOY5QMxqDJD5MA9ZeaLkot3xtH26SwVQ 0=; X-IronPort-AV: E=Sophos;i="5.92,286,1650931200"; d="scan'208";a="211579520" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-33001.sea14.amazon.com with ESMTP; 20 Jul 2022 16:53:17 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1e-f771ae83.us-east-1.amazon.com (Postfix) with ESMTPS id 42F45121708; Wed, 20 Jul 2022 16:53:16 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Wed, 20 Jul 2022 16:53:15 +0000 Received: from 88665a182662.ant.amazon.com (10.43.160.159) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Wed, 20 Jul 2022 16:53:12 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern CC: Kuniyuki Iwashima , Kuniyuki Iwashima , Subject: [PATCH v1 net 10/15] tcp: Fix a data-race around sysctl_tcp_challenge_ack_limit. Date: Wed, 20 Jul 2022 09:50:21 -0700 Message-ID: <20220720165026.59712-11-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220720165026.59712-1-kuniyu@amazon.com> References: <20220720165026.59712-1-kuniyu@amazon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.160.159] X-ClientProxiedBy: EX13D10UWA004.ant.amazon.com (10.43.160.64) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org While reading sysctl_tcp_challenge_ack_limit, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2") Signed-off-by: Kuniyuki Iwashima --- 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 debfff94f3af..d386a69b1c05 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3629,7 +3629,7 @@ static void tcp_send_challenge_ack(struct sock *sk) /* Then check host-wide RFC 5961 rate limit. */ now = jiffies / HZ; if (now != challenge_timestamp) { - u32 ack_limit = net->ipv4.sysctl_tcp_challenge_ack_limit; + u32 ack_limit = READ_ONCE(net->ipv4.sysctl_tcp_challenge_ack_limit); u32 half = (ack_limit + 1) >> 1; challenge_timestamp = now; -- 2.30.2