[Pkg-virtualbox-devel] Bug#553918: Bug#553918: virtualbox-ose-source: Please, make dkms a recommendation.

[Wolfgang Walter]

Am Donnerstag, 12. November 2009 schrieb Michael Meskes:
> On Fri, Nov 06, 2009 at 08:06:33PM +0100, Wolfgang Walter wrote:
> > 2) It therefor runs as root. And it even does if /lib/modules/<installed
> > kernel>/source points to a non privileged build directory which is a
> > security problem.
>
> I don't really see where the security problem is here. Would you mind
> explaining it?
>

Say you built your kernel as user foo on one machine.

Say
	/lib/modules/2.6.31.6/source
or 
	/lib/modules/2.6.31.6/build
therefor may points to
	/home/foo/kernels/linux-2.6.31.6


Now you install that kernel on a different machine "exposed" where user foo 
exists, too. 

You now have to trust machine "exposed". You must trust foo at exposed that it 
does not provide a manipulated /home/foo/kernels/linux-2.6.31.6 which will 
either produce a trojaned kernel module or simply uses errors in dkms, gcc, 
binutils, ... to gain root access.

I think virtualbox should do it like other similar packages which build kernel 
modules:

virtualbox-ose-source for building binary-modules as self-sufficent 
deb-packages

virtualbox-ose-dkms for the dkms approach

Sehe batman-adv-source|dkms or openafs-modules-source|dkms

Regards,
-- 
Wolfgang Walter
Studentenwerk München
Anstalt des öffentlichen Rechts
Leiter EDV
Leopoldstraße 15
80802 München
Tel: +49 89 38196 276
Fax: +49 89 38196 150
Email: wolfgang.walter at stwm.de
http://www.studentenwerk-muenchen.de/