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 66859C00144 for ; Mon, 1 Aug 2022 11:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231842AbiHALvb (ORCPT ); Mon, 1 Aug 2022 07:51:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231446AbiHALue (ORCPT ); Mon, 1 Aug 2022 07:50:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B20A73AE47; Mon, 1 Aug 2022 04:49:14 -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 D982B612C6; Mon, 1 Aug 2022 11:49:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4D69C433C1; Mon, 1 Aug 2022 11:49:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354553; bh=LIcRHKYKYlzajg/YMOhVk1Ufpco9mjpW0QZrPm6QgCA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2i5j0mPavSthhlaoNalmxQjvvgO5qfKi3MfbmAiR2C7Rl/6NYXRp3NoBeO2yomCHW /895wjX8WwezCiNnaQ5ysnvJjGGKUNfX6H3Ra0+NxIt6/to6g0KQ7T3i4KIxExYwso HAAQhCwSDhA9JZL4L1xUT2rBrrBf+jipg8xKfEC8= 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 5.4 06/34] tcp: Fix a data-race around sysctl_tcp_adv_win_scale. Date: Mon, 1 Aug 2022 13:46:46 +0200 Message-Id: <20220801114128.304976802@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220801114128.025615151@linuxfoundation.org> References: <20220801114128.025615151@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 36eeee75ef0157e42fb6593dcc65daab289b559e upstream. While reading sysctl_tcp_adv_win_scale, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1389,7 +1389,7 @@ void tcp_select_initial_window(const str static inline int tcp_win_from_space(const struct sock *sk, int space) { - int tcp_adv_win_scale = sock_net(sk)->ipv4.sysctl_tcp_adv_win_scale; + int tcp_adv_win_scale = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_adv_win_scale); return tcp_adv_win_scale <= 0 ? (space>>(-tcp_adv_win_scale)) :