[Eug-lug] EDITOR'S NOTE:

[Po Petz]

On Thu, 5 Aug 2004, Bob Miller wrote:

> Jacob Meuser wrote:
>
> > But then again, using safer functions, W^X, randomized memory allocation
> > and mapping, privilege separation, propolice, etc, minimize the risk
> > of bugs becoming serious security problems.  Some of these things are
> > available for linux, but in OpenBSD they are there by default.
>
> What's W^X?

Shorthand for "Writable or Executable."  It's an OpenBSD kernel
enhancement (and loader too, I think) that allows areas of memory to be
marked explicitly with a flag that ensures that parts of memory are not
simultaneously writeable and executable.  Good for stopping a class of
attacks on the x86 platform.

The "PaX" project has something similar for linux.
http://pax.grsecurity.net/docs/

-po