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 8C196C0015E for ; Tue, 25 Jul 2023 11:11:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234170AbjGYLLV (ORCPT ); Tue, 25 Jul 2023 07:11:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45360 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234173AbjGYLLE (ORCPT ); Tue, 25 Jul 2023 07:11:04 -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 1A3C52D71 for ; Tue, 25 Jul 2023 04:10:09 -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 5DBA461655 for ; Tue, 25 Jul 2023 11:10:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E1B7C433C8; Tue, 25 Jul 2023 11:10:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1690283408; bh=8kTh0L/Gv3syxNOFLKd5RSbw1jhRQOamZaGYjoaA2K4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=odAUSxInoL6RBsON1bnydnN7r2QNfPh3shU1Gco5hw8SxhHFXchikkf/6Z55GbKyg dsN6uiLM04IPmBtYUrhsAL/MCc2SyWPar888sr6VgPkaaCGn7jos2//CNF5vYdWcFc n4OscV2jdcAtUFIvVir2njhtlzQGm2wIXkcEpj9Q= 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 5.15 66/78] tcp: annotate data-races around tp->keepalive_time Date: Tue, 25 Jul 2023 12:46:57 +0200 Message-ID: <20230725104453.834459514@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230725104451.275227789@linuxfoundation.org> References: <20230725104451.275227789@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 4164245c76ff906c9086758e1c3f87082a7f5ef5 ] do_tcp_getsockopt() reads tp->keepalive_time 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/20230719212857.3943972-4-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/net/tcp.h | 7 +++++-- net/ipv4/tcp.c | 3 ++- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index fdac6913b6c8f..f9a24f48fa986 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1481,9 +1481,12 @@ static inline int keepalive_intvl_when(const struct tcp_sock *tp) static inline int keepalive_time_when(const struct tcp_sock *tp) { struct net *net = sock_net((struct sock *)tp); + int val; - return tp->keepalive_time ? : - READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); + /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ + val = READ_ONCE(tp->keepalive_time); + + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); } static inline int keepalive_probes(const struct tcp_sock *tp) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 8ff86431f44b4..54219e2080019 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3317,7 +3317,8 @@ int tcp_sock_set_keepidle_locked(struct sock *sk, int val) if (val < 1 || val > MAX_TCP_KEEPIDLE) return -EINVAL; - tp->keepalive_time = val * HZ; + /* Paired with WRITE_ONCE() in keepalive_time_when() */ + WRITE_ONCE(tp->keepalive_time, val * HZ); if (sock_flag(sk, SOCK_KEEPOPEN) && !((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))) { u32 elapsed = keepalive_time_elapsed(tp); -- 2.39.2