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 3EF7FC19F29 for ; Mon, 1 Aug 2022 11:53:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232204AbiHALxk (ORCPT ); Mon, 1 Aug 2022 07:53:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232038AbiHALxB (ORCPT ); Mon, 1 Aug 2022 07:53:01 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C194843E57; Mon, 1 Aug 2022 04:50:07 -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 4F6D2B81163; Mon, 1 Aug 2022 11:50:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF9A8C433C1; Mon, 1 Aug 2022 11:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354605; bh=K0CASPXfYFvHUtrCPMZiq0XFMgsCO1fnzPBCs9cEBKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xxspm+oucdoNXYAYQCBwQ2cy/g2j/ydo42Yw8IxbmiqSKg4ByO9FXm6nfHboumFk+ YlVruivg5zFvK2tKN0bgjWx6UrIYJspdEuOur8vylfGPntXNHyrIAYQjRpsLa1WTeM jW43uvaWArVrD8b9KcRAG6mCtQ3m+spWVUvlnPEE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" Subject: [PATCH 5.10 20/65] tcp: Fix a data-race around sysctl_tcp_challenge_ack_limit. Date: Mon, 1 Aug 2022 13:46:37 +0200 Message-Id: <20220801114134.544580903@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114133.641770326@linuxfoundation.org> References: <20220801114133.641770326@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 commit db3815a2fa691da145cfbe834584f31ad75df9ff upstream. 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3576,7 +3576,7 @@ static void tcp_send_challenge_ack(struc /* 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;