Re: Re: Offset2lib: bypassing full ASLR on 64bit Linux

[Daniel Micay <danielmicay () gmail com>]

On 05/12/14 08:18 PM, Andy Lutomirski wrote:
> On 12/05/2014 04:44 PM, Hanno Böck wrote:
> > On Fri, 05 Dec 2014 17:43:44 -0500
> > Daniel Kahn Gillmor <dkg-QLrU/DhXBlmnlhUoGqYIEF6hYfS7NtTn () public gmane org> wrote:
> >
> > > i couldn't find a reference to this in the nautilus bugtracker, so i
> > > just posted:
> > >
> > >  https://bugzilla.gnome.org/show_bug.cgi?id=741183
> >
> > I tried to dig into this a bit. I'm not really sure, but based on the
> > output I assume nautilus is relying on file or libmagic to assess the
> > file type.
> >
> > And that's what fails:
> > $ file --mime-type pie
> > pie: application/x-sharedlib
> >
> >
> > It seems there is no really easy way to separate executables from
> > shared libraries and whether this should be considered a bug in
> > file/libmagic. The only thing I quickly found that would be possible is
> > searching if a SONAME is present. libmagic uses some "magic" file
> > format to parse files, I don't know if that's capable of such complex
> > parsing.
>
> Why does gcc and/or ld write a non-zero entry point?  If they didn't,
> that would be an easy way to check.
>
> --Andy

There are some libraries like glibc's /usr/lib/libc.so.6 with valid
entry points, so file would still have trouble disambiguating that way.

I don't really think this is a problem for libmagic/file to solve, if
it's really a problem at all. Nautilus could just remove support for
executing traditional executables too... using CLI utilities that way
isn't going to work out and GUI ones have desktop files.

Attachment: signature.asc
Description: OpenPGP digital signature