There was a "off by one quad word" error in x86_64 ptrace. This was originally thought to be unexploitable because it will only store into a unused area, but better to plug it. However Andi Kleen stated that it allows a write to a word 40 bytes into the page above the kernel stack of a process which may be exploitable. http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=c4d1fcf3a2ea89b6d6221fa8b4588c77aff50995
Created attachment 117054 [details] Proposed patch
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2005-514.html