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From:   Pedro Falcato <pedro.falcato@gmail.com>
Date:   Fri, 11 Nov 2022 17:14:47 +0000
Message-ID: <CAKbZUD0aGmrb=GtK_sQM54LtajKLfArkKjrV7f7BaVyKGhQwgw@mail.gmail.com>
Subject: Re: [PATCH v3] fs/binfmt_elf: Fix memsz > filesz handling
To:     Kees Cook <keescook@chromium.org>
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org, dalias@libc.org,
        ebiederm@xmission.com, sam@gentoo.org, viro@zeniv.linux.org.uk
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On Fri, Nov 11, 2022 at 6:15 AM Kees Cook <keescook@chromium.org> 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@kernel.org/
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