The following upstream patch checks if ptrace RIP is canonical; without this a user can cause a crash. http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=d1099e8a18960693c04507bdd7b9403db70bfd97
This appears to be a duplicate of BZ, 154451. *** This bug has been marked as a duplicate of 154451 ***