Re: CVE-2014-0131 -- kernel: net: use-after-free during segmentation with zerocopy

[Petr Matousek <pmatouse () redhat com>]

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 () redhat 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