Re: [PATCH] System Wide Capability Bounding Set

From: Steve Grubb
Date: Thu Jan 27 2011 - 11:50:55 EST


On Thursday, January 27, 2011 11:35:13 am Andrew G. Morgan wrote:
> > Today, people want to have multi-tenant hosting using virtual
> > machines whereby they give away root control of the guest VM.
> > If you were renting system space, you would expect root access.
> > That would make a nice juicy hacking target because you don't know
> > who else is sharing the physical machine with you and they might
> > have something in their VM worth stealing.
>
> Which root filesystem (/) do kernel helpers run in in such a virtual setup?

I would assume that root in the VM could umount and mount anything. Or bind mount over
it. We really want any change to a global bounding set done before initrd finishes
doing its thing. This way there is no chance for mischief by the time control is
turned over to /sbin/init - which root controls.

-Steve
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