grsecurity forums

Hi,

does grsecurity 1.9.13 protect against recent do_mremap bug?
Original advisory is here:
http://isec.pl/vulnerabilities/isec-0012-mremap.txt
Exploit code is here:
http://www.security.nnov.ru/files/mremap_poc.c

Best Wishes,
Viktors

I forgot to specify kernel version: 2.4.23. I know that .24 is out, but maybe there's no reason to upgrade if grsecurity gives enough protection.

the PoC as is seems to fail on 2.4.23-grsec-1.9.13 as long as SEGMEXEC is enabled for it. i'm trying to make it work with SEGMEXEC enabled but not having much luck...

daemon2k wrote:the PoC as is seems to fail on 2.4.23-grsec-1.9.13 as long as SEGMEXEC is enabled for it. i'm trying to make it work with SEGMEXEC enabled but not having much luck...

where did you get this exploit from? i want to test my system too..

I pulled it from a bugtraq posting ( http://marc.theaimsgroup.com/?l=bugtraq ... 402129&w=2 ), but it's identical to the one at http://www.security.nnov.ru/files/mremap_poc.c shown above.

viktorsr wrote:does grsecurity 1.9.13 protect against recent do_mremap bug?

until a working exploit or method is made public, it's hard to tell. what i know for sure is that neither PaX nor grsecurity prevents the bug from getting triggered, so as always, better upgrade than wait and get bitten. a note on SEGMEXEC: while it prevents the posted proof-of-concept code from working it's trivial to overcome, just chpax -s the executable.