Re: [PATCH v3] fs/binfmt_elf: Fix memsz > filesz handling

From: Pedro Falcato
Date: Fri Nov 11 2022 - 12:15:05 EST


On Fri, Nov 11, 2022 at 6:15 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
>
> On Fri, Nov 11, 2022 at 03:59:08AM +0000, Pedro Falcato wrote:
> > We could of course also just sort the program headers at load time,
> > but I assume that's unwanted overhead for most well behaved ELF
> > program headers :)
>
> Large refactoring of the ELF loader needs proper unit testing, and we're
> still a bit away from that existing. In the meantime, we'll need to make
> very very small changes to fix bugs. I've sent a minimal change which I
> think should fix the problem (now at v2 since right after sending it I
> realized I was trading one accidentally correct state for another in the
> v1):
> https://lore.kernel.org/linux-hardening/20221111061315.gonna.703-kees@xxxxxxxxxx/
Got it. I understand you may be a bit nervous deploying this patch ATM.

What are we missing for ELF loader kunit testing? How can one help?

Note that my -v1 is still relatively safe and was already tested, you
could just apply that.

Thanks,
Pedro