Re: [gentoo-hardened] 2.6.27-hardened-r8: assassination

[Mike Frysinger <vapier@gentoo.org>]

On Tue, Mar 8, 2011 at 3:49 PM, Anthony G. Basile wrote:
> On 03/08/2011 02:05 PM, Mike Frysinger wrote:
>> On Tue, Mar 8, 2011 at 1:40 PM, Alex Efros wrote:
>>> On Fri, Mar 06, 2009 at 03:25:16PM -0800, Ned Ludd wrote:
>>>>> On Fri, Mar 06, 2009 at 11:12:59PM +0200, pageexec@freemail.hu wrote:
>>>>>> ah crap, i know what it is. it's a several years old glibc bug where someone
>>>>>> put a certain variable into the RELRO segment but forgot that it'll be written
>>>>>> to later when a library with RWE GNU_STACK is loaded. the workaround is
>>>>>> to find that library (just extract them from strace, probably it'll be
>>>>>> pari's library) and run execstack -c on it.
>>>>>
>>>>> I don't have execstack command. Looks like it belong to prelink package,
>>>>> but http://www.gentoo.org/doc/en/prelink-howto.xml states it's
>>>>> incompatible with hardened. Because of this I decide to compile it
>>>>> manually, just to get execstack command:
>>>>>
>>>>> # emerge -f prelink
>>>>> # cd /usr/src
>>>>> # tar xjvf /usr/portage-distfiles/prelink-20071009.tar.bz2
>>>>> # cd prelink
>>>>> # ./configure && make
>>>>>
>>>>> Now I tried your workaround:
>>>>>
>>>>> # /usr/src/prelink/src/execstack -c /usr/lib/perl5/site_perl/5.8.8/i686-linux/auto/Math/Pari/Pari.so
>>>>> # /usr/src/prelink/src/execstack -c /usr/local/ioncube/ioncube_loader_lin_5.2.so
>>>>> # /usr/src/prelink/src/execstack -c /usr/local/Zend/lib/ZendExtensionManager.so
>>>>> # /usr/src/prelink/src/execstack -c /usr/local/Zend/lib/ZendExtensionManager_TS.so
>>>>> # /usr/src/prelink/src/execstack -c /usr/local/Zend/lib/Optimizer-3.3.0/php-5.2.x/ZendOptimizer.so
>>>>>
>>>>> and it works!!
>>>>>
>>>>> Is this issue will be fixed in next stable hardened-sources?
>>>>
>>>> FYI.. PaX Team maintains the PaX kernel and has little control over what
>>>> fixes go into the "next" hardened-sources. Also seems to me a little
>>>> strange that the PaX Team would have to put a work-around in the kernel
>>>> for a bug in glibc.. Seems like glibc should be fixed vs the kernel.
>>>
>>> 2 years later… Just updated system, bug still exists, and I still have to
>>> use execstack workaround for zendoptimizer and ioncube.
>>
>> like they said, this doesnt seem to be a bug in the kernel, so the pax
>> source arent going to be changing
>>
>> if there's a bug in glibc, an actual bug in bugs.g.o needs to be
>> opened with real details/patches.  otherwise, nothing is going to
>> change.
>
> Nothing to say that Mike hasn't already said.  pipacs knows about this
> but what can he do?  Good luck with upstream glibc.  Next time I speak
> with pipacs I can bring it up, see if anything is changing.  I doubt it.

if there is a real bug in glibc that drepper is ignoring, that doesnt
mean we cant merge it into Gentoo's glibc.  hence open a bug in
bugs.g.o with the patch for me to review.
-mike