Re: [PATCH] mm: Prevent mapping slab pages to userspace

[Matthew Wilcox <willy@xxxxxxxxxxxxx>]

On Sat, Jan 26, 2019 at 07:44:40AM +1300, Kees Cook wrote:
> > -       if (PageAnon(page))
> > +       if (PageAnon(page) || PageSlab(page))
> 
> Are there other types that should not get mapped? (Or better yet, is
> there a whitelist of those that are okay to be mapped?)

Funny you should ask; I think the next patch in this series looks like this:

-       if (PageAnon(page) || PageSlab(page))
+       if (PageAnon(page) || PageSlab(page) || page_has_type(page))

but let's see if there's something I've overlooked with this patch.