From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753763AbaBQAB1 (ORCPT ); Sun, 16 Feb 2014 19:01:27 -0500 Received: from imap.thunk.org ([74.207.234.97]:58708 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752902AbaBQABZ (ORCPT ); Sun, 16 Feb 2014 19:01:25 -0500 Date: Sun, 16 Feb 2014 19:01:17 -0500 From: "Theodore Ts'o" To: Vegard Nossum Cc: Kalpak Shah , Andreas Dilger , linux-ext4@vger.kernel.org, LKML Subject: Re: ext4 info leak in creation times in latest mainline Message-ID: <20140217000117.GC12947@thunk.org> Mail-Followup-To: Theodore Ts'o , Vegard Nossum , Kalpak Shah , Andreas Dilger , linux-ext4@vger.kernel.org, LKML References: <5300DEC5.2080908@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5300DEC5.2080908@oracle.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Feb 16, 2014 at 04:52:37PM +0100, Vegard Nossum wrote: > There seems to be a bug in ext4 where the i_crtime of struct > ext4_inode_info is not initialised, so (some) creation times contain > essentially random values.... > > I don't know if it's relevant, but the filesystem is actually ext3 > mounted using ext4. It's 100% reproducible for me, so I can test > patches. Thanks for the bug report. I see the problem; it was indeed relevant that this was an ext3 file systmem mounted as ext4. The first time when an ext3 inode is read by ext4, i_extra_isize is too small, and so there is no i_crtime field. The bug is in EXT4_EINODE_GET_XTIME() (in ext4.h, where it is leaving ei->i_crtime.tv_sec uninitialized. It's an easy fix. I'll send out a patch shortly. Cheers, - Ted