Hi, quoting grsec developer: "Using the RBAC system's PaX flag support to enforce system-wide MPROTECT enabling could have prevented triggering of the bug, since it requires the creation of an executable stack to trigger the vma mirroring bug." I 've tested the exploit on 2.6 kernel in an Alpha platform with MPROTECT RBAC protection activated -wich is our default setting :-)- and it doesn't work... hugo@alpha ~ $ ./xploit mprotect map1 base: Permission denied run chpax -m on this executable Moreover, even without MPROTECT activated it is important to remenber that OS security must never rely on a single layer... a well-configured Grsec system will render very difficult to exploit it -nor at least with a direct vector-. On Grsec case, there are some configurations can help prevent/difficult the exploitation: aggressive TPE (Trusted Path Execution) configuration + tight RBAC policy + Network Protections will make a pain to exploit this, even locally. Regards,
