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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun, 12 Dec 2021 10:29:01 -0800
Message-ID: <CAHk-=wiEgwj3DGZai2GF9+z-FCSS455kGZ9z2g1qtdPLPWpvxQ@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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On Sun, Dec 12, 2021 at 5:52 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Sat, Dec 11, 2021 at 11:38 PM Alexey Dobriyan <adobriyan@gmail.com> wrote:
> >
> > Why not let it segfault?
>
> Why let it segfault?

That's not my main worry - what if somebody has a code section with a
zero vaddr and intentionally put the entry at the beginning?

Maybe it's not supposed to work by some paper standatd, but afaik
currently it _would_ work.

All these things are relative to the load address, so a zero e_entry
doesn't mean NULL, and may be a perfectly valid address.

No?

            Linus