From patchwork Fri Jul 15 17:17:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 12919506 X-Patchwork-Delegate: kuba@kernel.org 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 23263C433EF for ; Fri, 15 Jul 2022 17:22:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235752AbiGORV7 (ORCPT ); Fri, 15 Jul 2022 13:21:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231901AbiGORV5 (ORCPT ); Fri, 15 Jul 2022 13:21:57 -0400 Received: from smtp-fw-6002.amazon.com (smtp-fw-6002.amazon.com [52.95.49.90]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4EA7183F2A for ; Fri, 15 Jul 2022 10:21:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1657905717; x=1689441717; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=nwP9yfrd7lHGHgFHjAp2/sXAAjnjdA5aKAbvPd+TMmA=; b=ee+TCrGnYQklzJxDq3Nu49Qm7/dUquNN9Egk//45ucMxEx0QMR4qwu6E JJ5IvXcCIjSUSEEaZ9WzeXyt8SN+P/VPIhSFt5jRZbj+8wv4Ab0xl5Pm/ MhqY55mvPbcMCYc2gFANxxQGIhuPaHE6eKQ0FSx8Y6wFweE/jez5tOD0K 4=; X-IronPort-AV: E=Sophos;i="5.92,274,1650931200"; d="scan'208";a="222238331" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-pdx-2a-6a4112b2.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-6002.iad6.amazon.com with ESMTP; 15 Jul 2022 17:21:45 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-pdx-2a-6a4112b2.us-west-2.amazon.com (Postfix) with ESMTPS id 3CE7F4C00D2; Fri, 15 Jul 2022 17:21:44 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.36; Fri, 15 Jul 2022 17:21:43 +0000 Received: from 88665a182662.ant.amazon.com (10.43.162.124) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1118.9; Fri, 15 Jul 2022 17:21:40 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , Yuchung Cheng Subject: [PATCH v1 net 14/15] tcp: Fix data-races around sysctl_tcp_fastopen. Date: Fri, 15 Jul 2022 10:17:54 -0700 Message-ID: <20220715171755.38497-15-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220715171755.38497-1-kuniyu@amazon.com> References: <20220715171755.38497-1-kuniyu@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.162.124] X-ClientProxiedBy: EX13D31UWA003.ant.amazon.com (10.43.160.130) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 --- CC: Yuchung Cheng --- 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 4bc24f9e38b3..59a0c5406fc1 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 b1b1bcbc4f60..2faaaaf540ac 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1150,7 +1150,8 @@ 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; @@ -3617,7 +3618,8 @@ 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;