A flaw was discovered  in how systemtap handled DWARF expressions when unwinding the stack. This could result in an invalid pointer read, leading to reading kernel memory, or a kernel panic (and if the kernel reboot on panic flag was set (panic_on_oops), it would cause the system to reboot).
In order to trigger this flaw, an admin would have to enable unprivileged mode (giving users membership in the 'stapusr' group and configuring the local machine with 'signer,all-users' stap-server trust). If an admin has enabled unprivileged mode, a user with such access could use this to crash the local machine.
A workaround is to disable unprivileged mode.
This will be corrected in a forthcoming upstream release of systemtap, and is currently fixed in git . It is believed that this flaw was introduced via git commit 16d59279f , so would affect systemtap >= 1.4.
Created systemtap tracking bugs for this issue
Affects: fedora-all [bug 796329]
This issue has been addressed in following products:
Red Hat Enterprise Linux 5
Red Hat Enterprise Linux 6
Via RHSA-2012:0376 https://rhn.redhat.com/errata/RHSA-2012-0376.html