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In-Reply-To: <87ilx6u0kj.fsf@oldenburg.str.redhat.com>
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Fri, 5 Nov 2021 08:03:11 -0700
Message-ID: <CAMe9rOpmvg0U9amZ9ZGVkbunzAAXDVj+1XF1=7yTmeeaK_G22A@mail.gmail.com>
Subject: Re: [PATCH 2/2] elf: Detect PT_LOAD segments that extend beyond EOF
 and refuse loading
To: Florian Weimer <fweimer@redhat.com>
Cc: GNU C Library <libc-alpha@sourceware.org>
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On Fri, Nov 5, 2021 at 7:41 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu:
>
> > So dlopen should reject it.   Can you identify the broken tools which
> > generate such input files and black list them for this test?
>
> It's objcopy --only-keep-debug, and it behaves as expted Separated
> debuginfo is broken by design.  The program headers do not correspond to
> the file contents, but match the original ELF file.

So the current checks aren't sufficient and your patch also checks
file size.  On x86-64, where is the first failed check? Why doesn't it
need to check file size?

> > Of course, ld.so can improve sanity checks.  But we need really broken
> > inputs for such checks.
>
> elf/tst-debug1 deliberately uses a broken input file.
>
> Thanks,
> Florian
>


-- 
H.J.