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 198E9C3F6B0 for ; Wed, 27 Jul 2022 17:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237264AbiG0RKC (ORCPT ); Wed, 27 Jul 2022 13:10:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241701AbiG0RJc (ORCPT ); Wed, 27 Jul 2022 13:09:32 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C377743C9; Wed, 27 Jul 2022 09:41:05 -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 2672A601C3; Wed, 27 Jul 2022 16:41:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F233C433B5; Wed, 27 Jul 2022 16:41:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658940062; bh=fVvNtlgbgAe6ClvXquGjijDpiSBJVzaHL91Kx5ew4Uk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qSCoePc2Gi9gJwFYn4Ivn6fHIEXdZPDtMQ4/B9PrmWSIOptuzfOI5wWAFwNG4eMbL s7z6Ejw+ysdpZ46xMVJb2i54IlGYF4n+gijF+JXQWg9BeWKbLs/W3U51AO4c7qYHsw EmNcpNIl66pYI8ret3/ox+Owhzar0uGQfV4bxnJA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kuniyuki Iwashima , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 091/201] tcp: Fix data-races around sysctl_tcp_syn(ack)?_retries. Date: Wed, 27 Jul 2022 18:09:55 +0200 Message-Id: <20220727161031.529543535@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220727161026.977588183@linuxfoundation.org> References: <20220727161026.977588183@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: stable@vger.kernel.org From: Kuniyuki Iwashima [ Upstream commit 20a3b1c0f603e8c55c3396abd12dfcfb523e4d3c ] While reading sysctl_tcp_syn(ack)?_retries, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/inet_connection_sock.c | 3 ++- net/ipv4/tcp.c | 3 ++- net/ipv4/tcp_timer.c | 10 +++++++--- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index d3bbb344bbe1..a53f9bf7886f 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -829,7 +829,8 @@ static void reqsk_timer_handler(struct timer_list *t) icsk = inet_csk(sk_listener); net = sock_net(sk_listener); - max_syn_ack_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries; + max_syn_ack_retries = icsk->icsk_syn_retries ? : + READ_ONCE(net->ipv4.sysctl_tcp_synack_retries); /* Normally all the openreqs are young and become mature * (i.e. converted to established socket) for first timeout. * If synack was not acknowledged for 1 second, it means diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 4ac53c8f0583..e22a61b2ba82 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3974,7 +3974,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = keepalive_probes(tp); break; case TCP_SYNCNT: - val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; + val = icsk->icsk_syn_retries ? : + READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); break; case TCP_LINGER2: val = tp->linger2; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 4f3b9ab222b6..a234704e8163 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -239,7 +239,8 @@ static int tcp_write_timeout(struct sock *sk) if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { if (icsk->icsk_retransmits) __dst_negative_advice(sk); - retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; + retry_until = icsk->icsk_syn_retries ? : + READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); expired = icsk->icsk_retransmits >= retry_until; } else { if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1, 0)) { @@ -406,12 +407,15 @@ abort: tcp_write_err(sk); static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req) { struct inet_connection_sock *icsk = inet_csk(sk); - int max_retries = icsk->icsk_syn_retries ? : - sock_net(sk)->ipv4.sysctl_tcp_synack_retries + 1; /* add one more retry for fastopen */ struct tcp_sock *tp = tcp_sk(sk); + int max_retries; req->rsk_ops->syn_ack_timeout(req); + /* add one more retry for fastopen */ + max_retries = icsk->icsk_syn_retries ? : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_synack_retries) + 1; + if (req->num_timeout >= max_retries) { tcp_write_err(sk); return; -- 2.35.1