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 22E06C001E0 for ; Tue, 25 Jul 2023 11:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233914AbjGYLHZ (ORCPT ); Tue, 25 Jul 2023 07:07:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233973AbjGYLHG (ORCPT ); Tue, 25 Jul 2023 07:07:06 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 460E126B5 for ; Tue, 25 Jul 2023 04:05:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 97FB461656 for ; Tue, 25 Jul 2023 11:05:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EEE4C433C9; Tue, 25 Jul 2023 11:05:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690283150; bh=rESpSAXLLpkL8fKcfq33vMxzNM4rgXyHRy+ZYzqexes=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K0IlYPDgmQzHNsaScJj20/Oa2krMF75ZEA5J+AxcGSJJbrIDGlnsXa0MW7uvU4ZwF qHaPxV4vvqNYHHBLYAKzamv6srm6lpGLBHCPyv/wbQ1P18ZTu/sx++OYz00zMSOxkV exzTMXSes7n4ragCiGXjVcbRYCbHe9zD2OAGrJKg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.1 155/183] tcp: annotate data-races around tp->keepalive_intvl Date: Tue, 25 Jul 2023 12:46:23 +0200 Message-ID: <20230725104513.420904677@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104507.756981058@linuxfoundation.org> References: <20230725104507.756981058@linuxfoundation.org> User-Agent: quilt/0.67 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: Eric Dumazet [ Upstream commit 5ecf9d4f52ff2f1d4d44c9b68bc75688e82f13b4 ] do_tcp_getsockopt() reads tp->keepalive_intvl while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/tcp.h | 9 +++++++-- net/ipv4/tcp.c | 4 ++-- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 397c248102415..f39c44cbdfe62 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1511,9 +1511,14 @@ void tcp_leave_memory_pressure(struct sock *sk); static inline int keepalive_intvl_when(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_intvl); - return tp->keepalive_intvl ? : - READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); } static inline int keepalive_time_when(const struct tcp_sock *tp) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c0d7b226bca1a..d19cfeb78392d 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3451,7 +3451,7 @@ int tcp_sock_set_keepintvl(struct sock *sk, int val) return -EINVAL; lock_sock(sk); - tcp_sk(sk)->keepalive_intvl = val * HZ; + WRITE_ONCE(tcp_sk(sk)->keepalive_intvl, val * HZ); release_sock(sk); return 0; } @@ -3665,7 +3665,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, if (val < 1 || val > MAX_TCP_KEEPINTVL) err = -EINVAL; else - tp->keepalive_intvl = val * HZ; + WRITE_ONCE(tp->keepalive_intvl, val * HZ); break; case TCP_KEEPCNT: if (val < 1 || val > MAX_TCP_KEEPCNT) -- 2.39.2