From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:37704 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752680AbcGDH7Y (ORCPT ); Mon, 4 Jul 2016 03:59:24 -0400 Date: Mon, 4 Jul 2016 09:59:19 +0200 From: Jan Kara To: "Eric W. Biederman" Cc: Seth Forshee , Linux Containers , linux-fsdevel@vger.kernel.org, Linux API , James Bottomley , Djalal Harouni , "Serge E. Hallyn" , Andy Lutomirski , Jan Kara , Jann Horn , Michael Kerrisk Subject: Re: [PATCH review 07/11] vfs: Don't create inodes with a uid or gid unknown to the vfs Message-ID: <20160704075919.GA5200@quack2.suse.cz> References: <87ziq03qnj.fsf@x220.int.ebiederm.org> <20160702172035.19568-1-ebiederm@xmission.com> <20160702172035.19568-7-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160702172035.19568-7-ebiederm@xmission.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Sat 02-07-16 12:20:31, Eric W. Biederman wrote: > It is expected that filesystems can not represent uids and gids from > outside of their user namespace. Keep things simple by not even > trying to create filesystem nodes with non-sense uids and gids. > > Signed-off-by: "Eric W. Biederman" So if we have sb->s_user_ns that doesn't map UID and GID 0, root cannot directly create files in this filesystem. EOVERFLOW error will at least hint us where the problem is but still I'm suspecting this is going to create hard to debug configuration issues... I'm not sure if we can do anything about this but I wanted to point it out. Honza -- Jan Kara SUSE Labs, CR