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 BA6B5C04A68 for ; Wed, 27 Jul 2022 17:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242401AbiG0Rgy (ORCPT ); Wed, 27 Jul 2022 13:36:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241580AbiG0RfJ (ORCPT ); Wed, 27 Jul 2022 13:35:09 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 964C883F38; Wed, 27 Jul 2022 09:49:43 -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 3947AB821C5; Wed, 27 Jul 2022 16:49:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85EBCC433B5; Wed, 27 Jul 2022 16:49:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940581; bh=iOq/THUgDmDM/j3le23+VopMrd/Pn4Vz7KF6fBtqEMM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oiMIlCRagNimRVndyYkiWFg8QfdR0EK46MKFAYB3tihIRQFKqBnble6uunNeps9yB Ck1KmxUKyOs3w39Pi3ttO9F44rMcbYxSrrxDHCWp/7cdQeDiOtKslW/Dm70bTjJv4N cb3bPWdTvKzsC3DI5uyhg+vCTZllFA7bOYCdjuaE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , Yuchung Cheng , "David S. Miller" , Sasha Levin Subject: [PATCH 5.18 075/158] tcp: Fix data-races around sysctl_tcp_fastopen. Date: Wed, 27 Jul 2022 18:12:19 +0200 Message-Id: <20220727161024.517101568@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161021.428340041@linuxfoundation.org> References: <20220727161021.428340041@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 5a54213318c43f4009ae158347aa6016e3b9b55a ] While reading sysctl_tcp_fastopen, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 2100c8d2d9db ("net-tcp: Fast Open base") Signed-off-by: Kuniyuki Iwashima Acked-by: Yuchung Cheng Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/af_inet.c | 2 +- net/ipv4/tcp.c | 6 ++++-- net/ipv4/tcp_fastopen.c | 4 ++-- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index f5d5911a8abd..5c207367b3b4 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -217,7 +217,7 @@ int inet_listen(struct socket *sock, int backlog) * because the socket was in TCP_LISTEN state previously but * was shutdown() rather than close(). */ - tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen; + tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen); if ((tcp_fastopen & TFO_SERVER_WO_SOCKOPT1) && (tcp_fastopen & TFO_SERVER_ENABLE) && !inet_csk(sk)->icsk_accept_queue.fastopenq.max_qlen) { diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 164603527399..28db838e604a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1151,7 +1151,8 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, struct sockaddr *uaddr = msg->msg_name; int err, flags; - if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) || + if (!(READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) & + TFO_CLIENT_ENABLE) || (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) && uaddr->sa_family == AF_UNSPEC)) return -EOPNOTSUPP; @@ -3638,7 +3639,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, case TCP_FASTOPEN_CONNECT: if (val > 1 || val < 0) { err = -EINVAL; - } else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) { + } else if (READ_ONCE(net->ipv4.sysctl_tcp_fastopen) & + TFO_CLIENT_ENABLE) { if (sk->sk_state == TCP_CLOSE) tp->fastopen_connect = val; else diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index fdbcf2a6d08e..0acdb5473850 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -332,7 +332,7 @@ static bool tcp_fastopen_no_cookie(const struct sock *sk, const struct dst_entry *dst, int flag) { - return (sock_net(sk)->ipv4.sysctl_tcp_fastopen & flag) || + return (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) & flag) || tcp_sk(sk)->fastopen_no_cookie || (dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE)); } @@ -347,7 +347,7 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, const struct dst_entry *dst) { bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1; - int tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen; + int tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen); struct tcp_fastopen_cookie valid_foc = { .len = -1 }; struct sock *child; int ret = 0; -- 2.35.1