SystemTap 1.4 and earlier, when unprivileged (aka stapusr) mode is enabled, allows local users to cause a denial of service (divide-by-zero error and OOPS) via a crafted ELF program with DWARF expressions that are not properly handled by a stap script that performs context variable access.
https://rhn.redhat.com/errata/RHSA-2011-0842.html
https://bugzilla.redhat.com/show_bug.cgi?id=702687
http://www.securityfocus.com/bid/47934
http://www.mandriva.com/security/advisories?name=MDVSA-2011:155
http://www.mandriva.com/security/advisories?name=MDVSA-2011:154
http://sourceware.org/git/?p=systemtap.git%3Ba=commit%3Bh=fa2e3415185a28542d419a641ecd6cddd52e3cd9