Re: [PATCH] ELF: fix overflow in total mapping size calculation

From: Andrew Morton
Date: Tue Oct 05 2021 - 20:21:32 EST


On Sun, 3 Oct 2021 15:11:24 +0300 Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:

> Kernel assumes that ELF program headers are ordered by mapping address,
> but doesn't enforce it. It is possible to make mapping size extremely huge
> by simply shuffling first and last PT_LOAD segments.
>
> As long as PT_LOAD segments do not overlap, it is silly to require
> sorting by v_addr anyway because mmap() doesn't care.
>
> Don't assume PT_LOAD segments are sorted and calculate min and max
> addresses correctly.

It sounds good, but why do I have the feeling this will explode in some
unexpected fashion? Because it's elf, and that's what it does :(