Re: CVE request -- kernel: kvm: device assignment DoS

[Kurt Seifried <kseifried () redhat com>]

On 11/24/2011 10:49 AM, Petr Matousek wrote:
> It was found that kvm_vm_ioctl_assign_device function did not check if
> the user requesting assignment was privileged or not. Together with
> /dev/kvm being 666, unprivileged user could assign unused pci devices,
> or even devices that were in use and whose resources were not properly
> claimed by the respective drivers.
>
> Please note that privileged access was still needed to re-program the
> device to for example issue DMA requests. This is typically achieved by
> touching files on sysfs filesystem. These files are usually not
> accessible to unprivileged users.
>
> As a result, local user could use this flaw to crash the system.
>
> Reference:
> https://bugzilla.redhat.com/show_bug.cgi?id=756084
> http://thread.gmane.org/gmane.comp.emulators.kvm.devel/82043
>
> Thanks,
Please use CVE-2011-4347 for this issue.

-- 

-Kurt Seifried / Red Hat Security Response Team