linux-kernel - Re: PC speaker

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Message-ID: <4673212B.5010304@cfl.rr.com>
Date:	Fri, 15 Jun 2007 19:30:51 -0400
From:	Phillip Susi <psusi@....rr.com>
To:	Jan Engelhardt <jengelh@...putergmbh.de>
CC:	"R.F. Burns" <burnsrf@...il.com>,
	Lee Revell <rlrevell@...-job.com>, linux-kernel@...r.kernel.org
Subject: Re: PC speaker

Jan Engelhardt wrote:
> On Jun 15 2007 13:07, Phillip Susi wrote:
>> R.F. Burns wrote:
>>> However, over the past several weeks, the students have found more
>>> creative ways to abuse the PC speaker (outside of the OS.)  The Powers
>>> that Be are asking that the PC speakers be disabled completely.  With
>>> the small number of techs we have, it would be very impractical to go
>>> around to all systems and remove the PC speaker from each and every
>>> computer case.
>> Now I am curious; how are they getting the pc speaker to make any sound with
>> the kernel module disabled?
> 
> ioperm(), inb(), and outb() from userspace. Needs root, though. Or 
> /dev/port, with write. Which comes to the question how they gained root. 
> Perhaps live cd? In which case, the OP should, as recommended in this 
> thread already, deactivate choosing boot devices, if that's possible.
> 
> (Unfortunately, newer BIOSes with 'integrated bootmenu' with F8 or so, 
> but I have not seen a way to deactivate _that_ menu.)

He already said they don't have root access and that allowed him to stop 
them from accessing the sound card by setting appropriate permissions.

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