Re: CVE Request: linux-kernel priviledge escalation on ARM/perf

[Kurt Seifried <kseifried () redhat com>]

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On 08/16/2013 05:07 AM, Petr Matousek wrote:
> On Wed, Aug 14, 2013 at 05:37:32PM -0400, Vince Weaver wrote:
> > Hello
> >
> > I'm not really a security researcher, so hopefully I'm reporting
> > this in the proper way.
>
> Thank you for the report, Vince. I think that it is completely fine
> -)
>
> > I have a fuzzer tool for the perf_event_open() syscall that
> > found a few oopses on the ARM platform, which I reported to lkml
> > a week ago.
> >
> > One of the oopses can lead to a local privilege escalation on
> > ARM-perf. This fix can be found here: 
> > http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=7809/1
The discussion thread is:
> > https://lkml.org/lkml/2013/8/7/259
> >
> > The hope is this appears in 3.11-rc6 but my attempts to get the
> > people at security () vger kernel org to take this seriously didn't
> > really go very well.
> >
> > I do have code that will exploit the kernel and give me a root
> > shell on an ARM Pandaboard machine running 3.11-rc4.  The exploit
> > is a bit fragile though: + Only works on ARM + Elevates from
> > normal user to root, no special config required. perf_event
> > syscalls run as regular users, not sure why some think you need
> > root. + It does need a user-mappable address at an exact byte
> > offset from a pmu_struct in memory.  This limits things somewhat;
> > in my testing 3.11-rc kernels have INT_MIN at exactly the right
> > place but the exploit doesn't work on a 3.7.6 kernel, it just
> > oopses or crashes the machine.
>
> This looks valid to me. Unless someone has any objections, can you 
> please Kurt assign CVE to this issue?
>
> Thanks,

Please use CVE-2013-4254 for this issue.


- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
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