Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Salvatore Bonaccorso]

Hi Christoph,

On Thu, Mar 14, 2019 at 08:06:52PM +0100, Christoph Anton Mitterer wrote:
> Hey Ben, Salvatore.
> 
> Thanks for cherry-picking the bug for unstable.
> 
> AFAIU stretch and jessie[-backports] should be affected as well.
> Shouldn't it go there, too?

Yes it needs to be adressed there as well. I have already included the
fix in the next upload for stretch, cf.
https://salsa.debian.org/kernel-team/linux/commit/e6d100021039bdea8be12e5b882f767bb8a1b6b7

Regards,
Salvatore

Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Christoph Anton Mitterer]

Hey Ben, Salvatore.

Thanks for cherry-picking the bug for unstable.

AFAIU stretch and jessie[-backports] should be affected as well.
Shouldn't it go there, too?

At least at the upstream mailing list it was said[0] the the bug was
introduced around October 2008, which should be roughly kernel 2.6.23.

Cheers,
Chris.


[0] 
https://lore.kernel.org/linux-btrfs/cal3q7h599_kdpdfhmrqswnlxktanc7aaqbe+hm6jjpr37us...@mail.gmail.com/

Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Salvatore Bonaccorso]

Control: tags -1 + pending

On Sun, Feb 24, 2019 at 09:40:59AM +0100, Salvatore Bonaccorso wrote:
> Control: found -1 4.3~rc5-1~exp1
> Control: tags -1 + upstream patch
> 
> Upstream patch submission at
> https://lore.kernel.org/linux-btrfs/20190214151720.23563-1-fdman...@kernel.org/

Pending in git, 
https://salsa.debian.org/kernel-team/linux/commit/76a21e66e34fff09735813e6c13398bc29ff18ec

Salvatore

Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Salvatore Bonaccorso]

Control: found -1 4.3~rc5-1~exp1
Control: tags -1 + upstream patch

Upstream patch submission at
https://lore.kernel.org/linux-btrfs/20190214151720.23563-1-fdman...@kernel.org/

Regards,
Salvatore

Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Christoph Anton Mitterer]

Here's the "proper" patch:
https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg85515.html

Bug#922306: linux: btrfs corruption (compressed data + hole data)

[Christoph Anton Mitterer]

Source: linux
Version: 4.19.20-1
Severity: critical
Tags: upstream patch
Justification: causes serious data loss

Hi.

Apparently there was a longer existing data corruption bug in btrfs[0],
AFAIU it happened when compression was used together with holes in data
and there was *no* recognition by checksumming.

Seems some movement got into this the last days and a patch[1] may have
been found fixing the issue.


Due to potential silent data corruptpion it makes perhaps sense to
cherry pick that fix (maybe waiting for confirmation from upstream
whether it's the final one) instead of waiting for it being released
in some upcoming stable release?

Cheers,
Chris.


[0] https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg85407.html
[1] https://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg85492.html


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