[libvirt] QEMU soundcards vulnerable to jack retasking?

[Daniel P. Berrange]

On Thu, Nov 24, 2016 at 06:06:29PM +0100, bancfc at openmailbox.org wrote:
> Recent security research shows that soundcards support surreptitiously
> switching line-out jacks into line-in by modifying the software stack. The
> way modern speakers and headphones are designed makes them readily usable as
> microphones. The Intel High Definition (HD) Audio standards which all modern
> consumer soundcards are based mandates this stupidity.
> 
> https://arxiv.org/ftp/arxiv/papers/1611/1611.07350.pdf
> 
> Does anyone know if QEMU's emulated sound devices follow this standard? If
> yes then a malicious guest that can modify the virt sound hardware can turn
> PC speakers into surveillance devices even if the microphone is disabled on
> the host. The only solution is completely denying untrusted VMs access to a
> virtual sound device.
> 
> /CC'd the respective researchers for input on this too.

This is better sent to the QEMU mailing list, rather than libvirt, since
the former is where the QEMU audio experts are...

Regards,
Daniel
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