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 118D9C19F2D for ; Tue, 9 Aug 2022 18:06:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344094AbiHISGK (ORCPT ); Tue, 9 Aug 2022 14:06:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245729AbiHISF2 (ORCPT ); Tue, 9 Aug 2022 14:05:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2447F27CF4; Tue, 9 Aug 2022 11:02:30 -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 A6B4E61059; Tue, 9 Aug 2022 18:02:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FDE6C43140; Tue, 9 Aug 2022 18:02:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660068150; bh=RPpTH3ijHdIcyCKVdvgk0xcCqRlXftJTxWnJmnRkBSc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mqghpZnKH2DL0I5pFYprP0kEkxcXh2eFCMXochGjmu8/zBpezqNchVVrlPjr88TtE 2So7E9a5pfEpDa2YBhkIeR71fxNkcHlGghhm2lhHOlDvL+yTzqgHDs+rDApL9pkEB5 VwdA6Ov57EvQraI9JdJ3mDfBZFdz9ity9t75QhaQ= 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 19/32] tcp: Fix a data-race around sysctl_tcp_comp_sack_delay_ns. Date: Tue, 9 Aug 2022 20:00:10 +0200 Message-Id: <20220809175513.692599259@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: linux-kernel@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 4866b2b0f7672b6d760c4b8ece6fb56f965dcc8a ] While reading sysctl_tcp_comp_sack_delay_ns, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 6d82aa242092 ("tcp: add tcp_comp_sack_delay_ns sysctl") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/tcp_input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 38412d93400a..b71866aba426 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5262,7 +5262,8 @@ static void __tcp_ack_snd_check(struct sock *sk, int ofo_possible) if (tp->srtt_us && tp->srtt_us < rtt) rtt = tp->srtt_us; - delay = min_t(unsigned long, sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns, + delay = min_t(unsigned long, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_comp_sack_delay_ns), rtt * (NSEC_PER_USEC >> 3)/20); sock_hold(sk); hrtimer_start(&tp->compressed_ack_timer, ns_to_ktime(delay), -- 2.35.1