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Subject: Re: attacking btrfs filesystems via UUID collisions?
To: Christoph Anton Mitterer <fo@fo>, Chris Murphy <lists@colorremedies.com>,
        "S.J." <sorry@anonym.com>
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From: Eric Sandeen <sandeen@redhat.com>
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Date: Fri, 11 Dec 2015 17:14:49 -0600
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On 12/11/15 4:21 PM, Christoph Anton Mitterer wrote:
>>  Note that Btrfs is
>> > not unique, XFS v5 does a very similar thing with volume UUID as
>> > well,
>> > and resulted in this change:
>> > http://oss.sgi.com/pipermail/xfs/2015-April/041267.html
> Do you mean that xfs may suffer from the same issues that we're talking
> about here? If so, one should probably give them a notice.

That was disabled temporarily because changing the fs UUID meant that
every piece of checksummed metadata with an embedded UUID would then
mismatch.

It was fixed (re-allowed) with

ce748ea xfs: create new metadata UUID field and incompat flag

in the kernel and

9c4e12f xfsprogs: Add new sb_meta_uuid field, update userspace tools to manipulate it

in xfsprogs. 

-Eric