[PATCH] vmap(): don't allow invalid pages

[Matthew Wilcox]

On Thu, Jan 20, 2022 at 04:54:03PM +0000, Russell King (Oracle) wrote:
> Well, I think I've adequately explained why I believe:
> 
> 	pfn_is_valid(page_to_pfn(page))
> 
> being used as the primary check is substandard, and will likely lead to
> a future CVE. When generating an array of struct page's, I believe that
> it is the responsibility for the generator to ensure that the array
> only contains valid pages.

So you're saying that virt_to_page() should be made more expensive?