** DISPUTED **  Unspecified vulnerability in the expand_stack function in grsecurity PaX allows local users to gain privileges via unspecified vectors. NOTE: the grsecurity developer has disputed this issue, stating that "the function they claim the vulnerability to be in is a trivial function, which can, and has been, easily checked for any supposed vulnerabilities."  The developer also cites a past disclosure that was not proven.  As of 20070120, the original researcher has released demonstration code.