[PATCH 2/3] mm: update core kernel code to use vm_flags_t consistently

[Kees Cook]

On Tue, Aug 05, 2025 at 06:13:56PM +0200, Uladzislau Rezki wrote:
> I agree. Also it can be even moved under vmalloc.c. There is only one
> user which needs it globally, it is usercopy.c. It uses find_vmap_area()
> which is wrong. See:
> 
> <snip>
> 	if (is_vmalloc_addr(ptr) && !pagefault_disabled()) {
> 		struct vmap_area *area = find_vmap_area(addr);
> 
> 		if (!area)
> 			usercopy_abort("vmalloc", "no area", to_user, 0, n);
> 
> 		if (n > area->va_end - addr) {
> 			offset = addr - area->va_start;
> 			usercopy_abort("vmalloc", NULL, to_user, offset, n);
> 		}
> 		return;
> 	}
> <snip>
> 
> we can add a function which just assign va_start, va_end as input
> parameters and use them in the usercopy.c. 

Yes please! I'd must rather use some exported validation routine than
having it hand-coded in usercopy.c. :)

-- 
Kees Cook