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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun, 12 Dec 2021 11:35:56 -0800
Message-ID: <CAHk-=wiKzE-+X7uZHELP-udnULXf75jog=UfO7GQ_gPXycELjw@mail.gmail.com>
Subject: Re: [PATCH] fs/binfmt_elf.c: disallow zero entry point address
To:     "H.J. Lu" <hjl.tools@gmail.com>
Cc:     Alexey Dobriyan <adobriyan@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
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[ Crossed emails ]

On Sun, Dec 12, 2021 at 11:30 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Linux, the start of the first PT_LOAD segment is the ELF
> header and the address 0 points to the ELF magic bytes which
> isn't a valid code sequence.

Yeah, then I think a much more valid argument (and patch) is _that_ argument.

So that kind of explanation, along with a patch more along the line of that

        if (elf_ex->e_entry < header_sizes)
                goto out;

I suggested, and not talking about paper standards that may or may not
be relevant.

That would be much more palatable to me - it's a _technical_ argument,
not a "some paper standard that we clearly have never followed"
argument.

                Linus