From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp2130.oracle.com ([141.146.126.79]:57512 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726081AbfDIDSL (ORCPT ); Mon, 8 Apr 2019 23:18:11 -0400 Date: Mon, 8 Apr 2019 20:18:01 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 4/4] xfs: don't allow most setxattr to immutable files Message-ID: <20190409031801.GD5147@magnolia> References: <155466882175.633834.15261194784129614735.stgit@magnolia> <155466884962.633834.14320700092446721044.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Amir Goldstein Cc: Dave Chinner , linux-xfs , Linux MM , linux-fsdevel , Ext4 , Linux Btrfs On Mon, Apr 08, 2019 at 09:20:47AM +0300, Amir Goldstein wrote: > On Sun, Apr 7, 2019 at 11:28 PM Darrick J. Wong wrote: > > > > From: Darrick J. Wong > > > > The chattr manpage has this to say about immutable files: > > > > "A file with the 'i' attribute cannot be modified: it cannot be deleted > > or renamed, no link can be created to this file, most of the file's > > metadata can not be modified, and the file can not be opened in write > > mode." > > > > However, we don't actually check the immutable flag in the setattr code, > > which means that we can update project ids and extent size hints on > > supposedly immutable files. Therefore, reject a setattr call on an > > immutable file except for the case where we're trying to unset > > IMMUTABLE. > > > > Signed-off-by: Darrick J. Wong > > Did you miss my comment on v1, or do you not think this use case > is going to hurt any application that is not a rootkit? > > chattr +i foo => OK > chattr +i foo => -EPERM Nah, I plain forgot to update the patch. :( Will send v2 where you're allowed to +i multiple times so long as that's the only thing you're changing. --D > Thanks, > Amir.