Subject: Re: Is this kernel fault OK?
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Todd Vierling <>
List: tech-kern
Date: 06/27/2003 09:02:38
On Thu, 26 Jun 2003, der Mouse wrote:

: > No, userland tools should never be able to crash the kernel (other
: > than root deliberately scribbling in kmem or something similar).
: I once tried to define what it is about things like
: 	dd if=/dev/zero of=/dev/mem
: that exempt them from the "userland should never be able to crash the
: kernel" dictum.  I never really got anywhere.  Any thoughts?

"Userland should never be able to crash a running kernel except when
accessing kernel memory space or raw filesystem data directly."

This becomes even more strict when securelevel >= 2, of course.

-- Todd Vierling <>