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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 B47C9C46464 for ; Fri, 10 Aug 2018 15:13:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 78A7722402 for ; Fri, 10 Aug 2018 15:13:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78A7722402 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=i-love.sakura.ne.jp Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728224AbeHJRnp (ORCPT ); Fri, 10 Aug 2018 13:43:45 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:40387 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727381AbeHJRnp (ORCPT ); Fri, 10 Aug 2018 13:43:45 -0400 Received: from fsav303.sakura.ne.jp (fsav303.sakura.ne.jp [153.120.85.134]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id w7AFBpjx037665; Sat, 11 Aug 2018 00:11:51 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav303.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav303.sakura.ne.jp); Sat, 11 Aug 2018 00:11:51 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav303.sakura.ne.jp) Received: from [192.168.1.8] (softbank126074194044.bbtec.net [126.74.194.44]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id w7AFBkAJ037587 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 11 Aug 2018 00:11:50 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: BUG: Mount ignores mount options To: "Eric W. Biederman" , David Howells Cc: viro@zeniv.linux.org.uk, John Johansen , Tejun Heo , selinux@tycho.nsa.gov, Paul Moore , Li Zefan , linux-api@vger.kernel.org, apparmor@lists.ubuntu.com, Casey Schaufler , fenghua.yu@intel.com, Greg Kroah-Hartman , Eric Biggers , linux-security-module@vger.kernel.org, Johannes Weiner , Stephen Smalley , tomoyo-dev-en@lists.sourceforge.jp, cgroups@vger.kernel.org, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Theodore Y. Ts'o" , Miklos Szeredi References: <153313703562.13253.5766498657900728120.stgit@warthog.procyon.org.uk> <87d0uqpba5.fsf@xmission.com> From: Tetsuo Handa Message-ID: <79f05de7-e600-675d-7bbf-c56faafc3134@i-love.sakura.ne.jp> Date: Sat, 11 Aug 2018 00:11:47 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <87d0uqpba5.fsf@xmission.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018/08/10 23:05, Eric W. Biederman wrote: > > There is a serious problem with mount options today that fsopen does not > address. The problem is that mount options are ignored for block based > filesystems, and any other type of filesystem that follows the same > pattern. > > The script below demonstrates this bug. Showing this bug can cause the > ext4 "acl" "quota" and "user_xattr" options to be silently ignored. > > fsopen has my nack until it addresses this issue. > > I don't know if we can fix this in the context of sys_mount. But we if > we are redoing the option parsing of how we mount filesystems this needs > to be fixed before we start worrying about bug compatibility. > > Hopefully this report is simple and clear enough that we can at least > agree on the problem. > > Eric This might be related to a problem that syzbot is failing to reproduce a problem. https://groups.google.com/forum/#!msg/syzkaller-bugs/R03vI7RCVco/0PijCTrcCgAJ syzbot found a reproducer, and the reproducer was working until next-20180803. But the reproducer is failing to reproduce this problem in next-20180806 despite there is no mm related change between next-20180803 and next-20180806. Therefore, I suspect that the reproducer is no longer working as intended. And there was parser change (David Howells' patch) between next-20180803 and next-20180806. I'm waiting for response from David Howells...