Local denial of service can be caused by running the "unhide" program. No details or patch I know of yet, see $URL for a reproducer.
I can reproduce this on 2.6.24-rc3-git1.
Fix: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=77034937dc4575ca0a76bf209838ecd39e804089