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 F0A80C04A68 for ; Wed, 27 Jul 2022 16:36:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238759AbiG0Qgh (ORCPT ); Wed, 27 Jul 2022 12:36:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239108AbiG0Qew (ORCPT ); Wed, 27 Jul 2022 12:34:52 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 441352BB14; Wed, 27 Jul 2022 09:27:36 -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 2F08D61662; Wed, 27 Jul 2022 16:26:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BCD50C433D7; Wed, 27 Jul 2022 16:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658939218; bh=bHWOYzOT2Xrewl7+mdQEPqZaXcMv9WJSN1IRkhw5VDU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z4JBFjGqQtnd+aol6GhBheIzomySszI73XCwcImk+yX3H5zYCeTDL9WNiO4uTZk7j EV8rqdukFahPpzMunE0cpF1OiwUvDgvw6cp0T7Fk4ZJRVOERY/p1LnGicTZEmP1ikn 7c+dkDD0hD7CY0pmC6QfwXXIf54VdsXqJezMs/CQ= 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 4.19 23/62] tcp: Fix data-races around sysctl_tcp_fastopen. Date: Wed, 27 Jul 2022 18:10:32 +0200 Message-Id: <20220727161005.109101571@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161004.175638564@linuxfoundation.org> References: <20220727161004.175638564@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 dadd42a07c07..229519001cc3 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -218,7 +218,7 @@ 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 0f89d0f2c21f..7acc0d07f148 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1160,7 +1160,8 @@ 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; @@ -3056,7 +3057,8 @@ static int do_tcp_setsockopt(struct sock *sk, int level, 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 119d2c2f3b04..f726591de7c7 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -313,7 +313,7 @@ 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)); } @@ -328,7 +328,7 @@ 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; -- 2.35.1