Re: UVM and the NULL page

[Joerg Sonnenberger <joerg%bec.de@localhost>]

On Thu, Jul 28, 2016 at 08:43:54PM +0200, Wolfgang Solfrank wrote:
> Hi,
> 
> > Currently, there is no real way to make sure a userland process won't be
> > able to allocate the NULL page.
> 
> Why should this be restricted?

It matters on architectures with shared user/kernel VA. If you can map
something to (void *)0, you can turn many dereferences of such address
into exploits.

Joerg