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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD622C43600 for ; Mon, 5 Apr 2021 09:02:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB13860238 for ; Mon, 5 Apr 2021 09:02:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237432AbhDEJCX (ORCPT ); Mon, 5 Apr 2021 05:02:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:42554 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237219AbhDEJAp (ORCPT ); Mon, 5 Apr 2021 05:00:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BBB4B6124C; Mon, 5 Apr 2021 09:00:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613239; bh=JG3rcj9yUPFQbNTf21qj+7dxIRrq32Sbt//oZalSZsI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jessx7rZZcT3j0aMfWvgc3Ic8HQmcpyAeH4dm6FT0++1TAt5/ZX0zsnYq9C//K7MI GJzgjoK42Gs0wsJ1+nNbEmL6FS/2Y7/ZebX6m1+Q4bS238iBHxKfOJuOC8I+ksxBYU bAnz0H3D6rA2XeJTFFCEW29IjxNnuc+b9xmekRzY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Ovechkin , Oleg Senin , Sasha Levin Subject: [PATCH 4.19 02/56] tcp: relookup sock for RST+ACK packets handled by obsolete req sock Date: Mon, 5 Apr 2021 10:53:33 +0200 Message-Id: <20210405085022.638938821@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085022.562176619@linuxfoundation.org> References: <20210405085022.562176619@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: Alexander Ovechkin commit 7233da86697efef41288f8b713c10c2499cffe85 upstream. Currently tcp_check_req can be called with obsolete req socket for which big socket have been already created (because of CPU race or early demux assigning req socket to multiple packets in gro batch). Commit e0f9759f530bf789e984 ("tcp: try to keep packet if SYN_RCV race is lost") added retry in case when tcp_check_req is called for PSH|ACK packet. But if client sends RST+ACK immediatly after connection being established (it is performing healthcheck, for example) retry does not occur. In that case tcp_check_req tries to close req socket, leaving big socket active. Fixes: e0f9759f530b ("tcp: try to keep packet if SYN_RCV race is lost") Signed-off-by: Alexander Ovechkin Reported-by: Oleg Senin Signed-off-by: Sasha Levin --- include/net/inet_connection_sock.h | 2 +- net/ipv4/inet_connection_sock.c | 7 +++++-- net/ipv4/tcp_minisocks.c | 7 +++++-- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h index fc9d6e37552d..da8a582ab032 100644 --- a/include/net/inet_connection_sock.h +++ b/include/net/inet_connection_sock.h @@ -288,7 +288,7 @@ static inline int inet_csk_reqsk_queue_is_full(const struct sock *sk) return inet_csk_reqsk_queue_len(sk) >= sk->sk_max_ack_backlog; } -void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); +bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req); void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req); void inet_csk_destroy_sock(struct sock *sk); diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 534e2598981d..439a55d1aa99 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -698,12 +698,15 @@ static bool reqsk_queue_unlink(struct request_sock_queue *queue, return found; } -void inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) +bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) { - if (reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req)) { + bool unlinked = reqsk_queue_unlink(&inet_csk(sk)->icsk_accept_queue, req); + + if (unlinked) { reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); reqsk_put(req); } + return unlinked; } EXPORT_SYMBOL(inet_csk_reqsk_queue_drop); diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 9436fb9b6a3d..a20b393b4501 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -815,8 +815,11 @@ embryonic_reset: tcp_reset(sk); } if (!fastopen) { - inet_csk_reqsk_queue_drop(sk, req); - __NET_INC_STATS(sock_net(sk), LINUX_MIB_EMBRYONICRSTS); + bool unlinked = inet_csk_reqsk_queue_drop(sk, req); + + if (unlinked) + __NET_INC_STATS(sock_net(sk), LINUX_MIB_EMBRYONICRSTS); + *req_stolen = !unlinked; } return NULL; } -- 2.30.1