Subject: Re: bad effect of keeping page table mapped in user space ?
To: Manuel Bouyer <>
From: Steven M. Bellovin <>
List: tech-kern
Date: 11/27/2007 01:21:30
On Tue, 27 Nov 2007 00:35:46 +0100
Manuel Bouyer <> wrote:

> Hi,
> can anyone see a bad side effect or security issue of having a
> process's page table mapped in the process's VM space ?
What is in the page table entries?  Can a user process overwrite them?
In particular, can a user process change which physical addresses are
referred to by arbitrary virtual addresses?  If so, there's a very
serious security issue.

		--Steve Bellovin,