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Date: Tue, 11 Mar 2014 18:09:32 +0100
From: Petr Matousek <pmatouse@...hat.com>
To: Chris Palmer <snackypants@...il.com>
Cc: oss-security@...ts.openwall.com
Subject: Re: CVE-2014-0131 -- kernel: net: use-after-free
 during segmentation with zerocopy

On Tue, Mar 11, 2014 at 09:50:45AM -0700, Chris Palmer wrote:
> It would be nice to clarify this bug description. It's a kernel memory
> disclosure bug (not a memory leak in the sense of failing to collect
> garbage).

Correct.

> Although UAF is often worse than that, it's not in this case,
> because there's 0 chance the after-free-user of the fragment will think the
> fragment is bigger than it is and subsequently write too much data into it.
> Is that right?

The after-free-user is a reader, not a writer.

> On Mar 10, 2014 9:41 AM, "Petr Matousek" <pmatouse@...hat.com> wrote:
> 
> > A flaw was found in the way segmentation was performed on skbs
> > originated from vhost-net when zerocopy feature was enabled.
> >
> > This flaw could be potentially used to leak kernel memory.
> >
> > Upstream patch submission:
> > http://marc.info/?l=linux-netdev&m=139446896921968&w=2
> >
> > --
> > Petr Matousek / Red Hat Security Response Team
> > PGP: 0xC44977CA 8107 AF16 A416 F9AF 18F3  D874 3E78 6F42 C449 77CA
> >

-- 
Petr Matousek / Red Hat Security Response Team
PGP: 0xC44977CA 8107 AF16 A416 F9AF 18F3  D874 3E78 6F42 C449 77CA

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