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 84812C25B0D for ; Tue, 9 Aug 2022 18:06:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343489AbiHISGE (ORCPT ); Tue, 9 Aug 2022 14:06:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43740 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344730AbiHISFl (ORCPT ); Tue, 9 Aug 2022 14:05:41 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3F9FFCD; Tue, 9 Aug 2022 11:02:33 -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 7DD7D6102F; Tue, 9 Aug 2022 18:02:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8988C43470; Tue, 9 Aug 2022 18:02:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660068153; bh=0agPFwrtUITObKzifFD7D/Pb+hzEpwXxQLiarBqFdVw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=um8JbDteB14og0GGSyUu8PwPAY2MvRje3FUGSKIqVLgztaDD0gnZ4tou+4qZ6tgg7 kBRc1WWFNQHS18UylBFuyBVFUTw17cfV8FmLBk3hi38AyF8aDdsHwFJHkYCWQhoLLf /EpShNvJsd+xawNaQSK1Tz1415JEwVj6CSadTNBk= 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 4.19 20/32] tcp: Fix a data-race around sysctl_tcp_comp_sack_nr. Date: Tue, 9 Aug 2022 20:00:11 +0200 Message-Id: <20220809175513.723352841@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220809175513.082573955@linuxfoundation.org> References: <20220809175513.082573955@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: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 79f55473bfc8ac51bd6572929a679eeb4da22251 ] While reading sysctl_tcp_comp_sack_nr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 9c21d2fc41c0 ("tcp: add tcp_comp_sack_nr sysctl") 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 b71866aba426..e1d065ea5a15 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5239,7 +5239,7 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) } if (!tcp_is_sack(tp) || - tp->compressed_ack >= sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr) + tp->compressed_ack >= READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_nr)) goto send_now; if (tp->compressed_ack_rcv_nxt != tp->rcv_nxt) { -- 2.35.1