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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 03C99C433DF for ; Thu, 4 Jun 2020 23:00:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8E652074B for ; Thu, 4 Jun 2020 23:00:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728114AbgFDXAe (ORCPT ); Thu, 4 Jun 2020 19:00:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726221AbgFDXAd (ORCPT ); Thu, 4 Jun 2020 19:00:33 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95BB5C08C5C0 for ; Thu, 4 Jun 2020 16:00:33 -0700 (PDT) Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id E88C211F5F8D1; Thu, 4 Jun 2020 16:00:32 -0700 (PDT) Date: Thu, 04 Jun 2020 16:00:32 -0700 (PDT) Message-Id: <20200604.160032.1940917295284318635.davem@davemloft.net> To: pabeni@redhat.com Cc: netdev@vger.kernel.org, mathew.j.martineau@linux.intel.com, kuba@kernel.org, mptcp@lists.01.org, edumazet@google.com, cpaasch@apple.com Subject: Re: [PATCH net] inet_connection_sock: clear inet_num out of destroy helper From: David Miller In-Reply-To: References: X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 04 Jun 2020 16:00:33 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni Date: Thu, 4 Jun 2020 18:55:45 +0200 > Clearing the 'inet_num' field is necessary and safe if and > only if the socket is not bound. The MPTCP protocol calls > the destroy helper on bound sockets, as tcp_v{4,6}_syn_recv_sock > completed successfully. > > Move the clearing of such field out of the common code, otherwise > the MPTCP MP_JOIN error path will find the wrong 'inet_num' value > on socket disposal, __inet_put_port() will acquire the wrong lock > and bind_node removal could race with other modifiers possibly > corrupting the bind hash table. > > Reported-and-tested-by: Christoph Paasch > Fixes: 729cd6436f35 ("mptcp: cope better with MP_JOIN failure") > Signed-off-by: Paolo Abeni Applied, thanks Paolo.