From: Theodore Ts'o <tytso@mit.edu>
To: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Kalpak Shah <kalpak@clusterfs.com>,
	Andreas Dilger <adilger@clusterfs.com>,
	linux-ext4@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
Subject: Re: ext4 info leak in creation times in latest mainline
Date: Sun, 16 Feb 2014 19:01:17 -0500	[thread overview]
Message-ID: <20140217000117.GC12947@thunk.org> (raw)
In-Reply-To: <5300DEC5.2080908@oracle.com>
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
     prev parent reply	other threads:[~2014-02-17  0:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-16 15:52 ext4 info leak in creation times in latest mainline Vegard Nossum
2014-02-17  0:01 ` Theodore Ts'o [this message]
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