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 E7DE3C00144 for ; Mon, 1 Aug 2022 11:52:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232051AbiHALwi (ORCPT ); Mon, 1 Aug 2022 07:52:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230255AbiHALwE (ORCPT ); Mon, 1 Aug 2022 07:52:04 -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 5E0CD3F30A; Mon, 1 Aug 2022 04:49:39 -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 ED714B8116D; Mon, 1 Aug 2022 11:49:38 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 641B2C433D6; Mon, 1 Aug 2022 11:49:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1659354577; bh=tvwONgUMdT/xk95Lk2G0aBmM8D9wZoH0L1zR3yd79NQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nDUMb9KNurwIFdTh05pALMi0HFMpQDlKsUPBvLY8Wj4ORUxbK17FOYtrv50Ubpbwn hJQzU2ozs9Z68PGq3Pl0s8EMaQoSFhKe+bG92PH5roSRken0tdXDk21+V93shpdnxU S0GbhcoGUesKJ1Yoo9MrsGBO0lb72yOw9PAOgA2k= 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 11/65] tcp: Fix a data-race around sysctl_tcp_frto. Date: Mon, 1 Aug 2022 13:46:28 +0200 Message-Id: <20220801114134.159617213@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 706c6202a3589f290e1ef9be0584a8f4a3cc0507 upstream. While reading sysctl_tcp_frto, 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 --- 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 @@ -2135,7 +2135,7 @@ void tcp_enter_loss(struct sock *sk) * loss recovery is underway except recurring timeout(s) on * the same SND.UNA (sec 3.2). Disable F-RTO on path MTU probing */ - tp->frto = net->ipv4.sysctl_tcp_frto && + tp->frto = READ_ONCE(net->ipv4.sysctl_tcp_frto) && (new_recovery || icsk->icsk_retransmits) && !inet_csk(sk)->icsk_mtup.probe_size; }