Re: [PATCH 4/7] mm: Introduce verify_page_range()

[Kees Cook]

On Mon, Apr 12, 2021 at 10:00:16AM +0200, Peter Zijlstra wrote:
> +struct vpr_data {
> +	int (*fn)(pte_t pte, unsigned long addr, void *data);
> +	void *data;
> +};

Eeerg. This is likely to become an attack target itself. Stored function
pointer with stored (3rd) argument.

This doesn't seem needed: only DRM uses it, and that's for error
reporting. I'd rather plumb back errors in a way to not have to add
another place in the kernel where we do func+arg stored calling.

-- 
Kees Cook