Re: _hardened_build not affecting libtool-compiled libraries
On Mon, Jun 24, 2013 at 08:46:51PM +0100, Richard W.M. Jones wrote:
On Mon, Jun 24, 2013 at 09:13:29PM +0200, Miloslav Trmač wrote:
> On Mon, Jun 24, 2013 at 8:46 PM, Richard W.M. Jones <rjones(a)redhat.com>
wrote:
> > but the plugins from that build are not hardened fully:
> Isn't it possible that the plugins are just so trivial that there were
> no opportunities for hardening?
>
> > $ hardening-check ./usr/lib64/nbdkit/plugins/nbdkit-example1-plugin.so
> > ./usr/lib64/nbdkit/plugins/nbdkit-example1-plugin.so:
> > Position Independent Executable: no, regular shared library (ignored)
> > Stack protected: no, not found!
> No on-stack arrays that I can find.
>
> > Fortify Source functions: no, only unprotected functions found!
> I can see libc calls with compile-time-known destination sizes except
> for example1_load () where it can be statically proven the call is
> safe.
Yes, I think you're right. I only checked the simple example*
plugins. The xz plugin which is rather more complicated does seem to
be protected:
$ hardening-check ./usr/lib64/nbdkit/plugins/nbdkit-xz-plugin.so
./usr/lib64/nbdkit/plugins/nbdkit-xz-plugin.so:
Position Independent Executable: no, regular shared library (ignored)
Stack protected: yes
Fortify Source functions: yes (some protected functions found)
Read-only relocations: yes
Immediate binding: yes
Note there is still a problem that an LDFLAGS hack was needed in the
spec file, otherwise libtool (or something) eats the hardening LDFLAGS.
Rich.
--
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