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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E6707C433DF for ; Wed, 1 Jul 2020 13:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDF8F206BE for ; Wed, 1 Jul 2020 13:26:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731063AbgGAN0F (ORCPT ); Wed, 1 Jul 2020 09:26:05 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:53713 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729429AbgGAN0E (ORCPT ); Wed, 1 Jul 2020 09:26:04 -0400 Received: from fsav109.sakura.ne.jp (fsav109.sakura.ne.jp [27.133.134.236]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 061DOXC9036582; Wed, 1 Jul 2020 22:24:33 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav109.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav109.sakura.ne.jp); Wed, 01 Jul 2020 22:24:33 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav109.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 061DOW2e036570 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 1 Jul 2020 22:24:32 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: linux-next: umh: fix processed error when UMH_WAIT_PROC is used seems to break linux bridge on s390x (bisected) To: Christian Borntraeger , Luis Chamberlain Cc: Christoph Hellwig , ast@kernel.org, axboe@kernel.dk, bfields@fieldses.org, bridge@lists.linux-foundation.org, chainsaw@gentoo.org, christian.brauner@ubuntu.com, chuck.lever@oracle.com, davem@davemloft.net, dhowells@redhat.com, gregkh@linuxfoundation.org, jarkko.sakkinen@linux.intel.com, jmorris@namei.org, josh@joshtriplett.org, keescook@chromium.org, keyrings@vger.kernel.org, kuba@kernel.org, lars.ellenberg@linbit.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org, nikolay@cumulusnetworks.com, philipp.reisner@linbit.com, ravenexp@gmail.com, roopa@cumulusnetworks.com, serge@hallyn.com, slyfox@gentoo.org, viro@zeniv.linux.org.uk, yangtiezhu@loongson.cn, netdev@vger.kernel.org, markward@linux.ibm.com, linux-s390 References: <3118dc0d-a3af-9337-c897-2380062a8644@de.ibm.com> <20200624144311.GA5839@infradead.org> <9e767819-9bbe-2181-521e-4d8ca28ca4f7@de.ibm.com> <20200624160953.GH4332@42.do-not-panic.com> <4e27098e-ac8d-98f0-3a9a-ea25242e24ec@de.ibm.com> <4d8fbcea-a892-3453-091f-d57c03f9aa90@de.ibm.com> <1263e370-7cee-24d8-b98c-117bf7c90a83@de.ibm.com> <20200626025410.GJ4332@42.do-not-panic.com> <20200630175704.GO13911@42.do-not-panic.com> From: Tetsuo Handa Message-ID: Date: Wed, 1 Jul 2020 22:24:29 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 2020/07/01 19:08, Christian Borntraeger wrote: > > > On 30.06.20 19:57, Luis Chamberlain wrote: >> On Fri, Jun 26, 2020 at 02:54:10AM +0000, Luis Chamberlain wrote: >>> On Wed, Jun 24, 2020 at 08:37:55PM +0200, Christian Borntraeger wrote: >>>> >>>> >>>> On 24.06.20 20:32, Christian Borntraeger wrote: >>>> [...]> >>>>> So the translations look correct. But your change is actually a sematic change >>>>> if(ret) will only trigger if there is an error >>>>> if (KWIFEXITED(ret)) will always trigger when the process ends. So we will always overwrite -ECHILD >>>>> and we did not do it before. >>>>> >>>> >>>> So the right fix is >>>> >>>> diff --git a/kernel/umh.c b/kernel/umh.c >>>> index f81e8698e36e..a3a3196e84d1 100644 >>>> --- a/kernel/umh.c >>>> +++ b/kernel/umh.c >>>> @@ -154,7 +154,7 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info) >>>> * the real error code is already in sub_info->retval or >>>> * sub_info->retval is 0 anyway, so don't mess with it then. >>>> */ >>>> - if (KWIFEXITED(ret)) >>>> + if (KWEXITSTATUS(ret)) >>>> sub_info->retval = KWEXITSTATUS(ret); Well, it is not br_stp_call_user() but br_stp_start() which is expecting to set sub_info->retval for both KWIFEXITED() case and KWIFSIGNALED() case. That is, sub_info->retval needs to carry raw value (i.e. without "umh: fix processed error when UMH_WAIT_PROC is used" will be the correct behavior).