Subject: Re: new kpi proposal, sysdisk(9)
To: Thor Lancelot Simon <tls@rek.tjls.com>
From: Bill Studenmund <wrstuden@netbsd.org>
List: tech-security
Date: 12/29/2006 22:18:24
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On Fri, Dec 29, 2006 at 05:55:47PM -0500, Thor Lancelot Simon wrote:
> On Fri, Dec 29, 2006 at 02:53:00PM -0800, Bill Studenmund wrote:
> >=20
> > We already have (or had, I haven't looked recently) code to ensure that=
=20
> > you don't open overlapping partitions. Combined with the whole-disk=20
> > partition, that lets us effectively merge the two (there is something y=
ou=20
> > open that is the whole disk).
>=20
> Elad and I looked at making this work for all ports, and with wedges, and
> concluded that it was basically hopeless.  The only safe and sane policy
> seems to be "if the kernel has any partition on this disk open, don't
> let users open any of them".

What makes it hopeless?

I agree we have a problem with wedges in that they act as independent=20
devices as opposed to magic, free-form partitions. Thus detecting overlap=
=20
is harder; we don't have a central repository like we do with a partition=
=20
table. But that's arguably a bug of our wedge implementation. ;-)

Take care,

Bill

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