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

[Christopher Lameter]

On Tue, 29 Jan 2019, Kees Cook wrote:

> It seems like a fatal condition to me? There's nothing to check that
> such a page wouldn't get freed by the slab while still mapped to
> userspace, right?

Lets just fail the code.  Currently this may work with SLUB. But SLAB and
SLOB overlay fields with mapcount. So you would have a corrupted page
struct if you mapped a slab page to user space.