[devel] suid binaries and ELF Auxiliary Vectors

[Kirill A. Shutemov]

On Fri, Sep 25, 2009 at 11:15 AM, Kirill A. Shutemov
<kirill �� shutemov.name> wrote:
> 2009/9/25 Konstantin A. Lepikhov <lakostis �� unsafe.ru>:
>> http://people.redhat.com/drepper/elftut1.ps -
>
> Thanks for link.
>
>> "The function create_elf_tables is responsible for
>> creating the user stack which includes creating the auxiliary vector."
>
> Yep, I see. It really creates auxv on suid binaries. At least it reaches
> copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))
> But still there is no auxv in userspace. :(
>

It seems problem is in glibc. When I compiled similar code with
klibc, it works fine.

Dmitry, could you comment it? Probably, it's security-related
thing. What's the point?