Re: CVE Request: Linux kernel: privilege escalation in user namespaces

[Fiedler Roman <Roman.Fiedler () ait ac at>]

> Von: Marc Deslauriers [mailto:marc.deslauriers () canonical com]
>
> Hi,
>
> On 2015-12-18 03:54 AM, Fiedler Roman wrote:
> > Hi,
> >
> > > Von: John Johansen [mailto:john.johansen () canonical com]
> > > Betreff: [oss-security] CVE Request: Linux kernel: privilege escalation 
> > > in
> > > user
> > > namespaces
> > >
> > > Hi,
> > >
> > > I haven't seen CVE request for this one yet so,
> > >
> > > Jann Horn reported a privilege escalation in user namespaces to the lkml
> > > mailing list
> > >
> > > https://lkml.org/lkml/2015/12/12/259
> > >
> > > if a root-owned process wants to enter a user namespace for some
> reason
> > > without knowing who owns it and therefore can't change to the
> namespace
> > > owner's uid and gid before entering, as soon as it has entered the
> > > namespace, the namespace owner can attach to it via ptrace and thereby
> > > gain access to its uid and gid.
> >
> > Could it be, that this is identical to
> >
> > https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1475050
> >
> > which led to
> >
> > https://bugs.launchpad.net/bugs/cve/2015-1334
> >
> > except, that combined with another timerace, this gives host uid 0
> escalation
> > no matter how the target namespace looks like or target uid is known or
> not?
> > The bug is marked as fixed, but looking at it, the very similar kernel 
> > issue
> > seems not be addressed and it is also still marked "private security"
> although
> > fix was released.
> >
> > I could ask Ubuntu Security if we should make that bug public or perhaps
> could
> > add accounts to the list of authorized users when told the Launchpad user
> name
> > to add.
>
> I've just made the bug public. It was an oversight that we hadn't made it
> public
> once the fix got released.

Has someone looked already, if the latest patches addressed the  same problem? 
Otherwise making https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1475050 
public just released a fully working zero day exploit.

Kind Regards,
Roman Fiedler

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