Linux kernel i386 SMP race condition Local Root Exploit

Kernel 2.4.x <= 2.4.29-rc2 and 2.6.x <= 2.6.10 are vulnerable

/*
* expand_stack SMP race local root exploit
*
* Copyright (C) 2005 Christophe Devine and Julien Tinnes
*
* This program is quite unreliable - you may have to run it
* several times before getting a rootshell. It was only tested
* so far on a bi-xeon running Debian testing / Linux 2.4.29-rc1.
*
* Vulnerability discovered by Paul Starzetz
* http://www.isec.pl/vulnerabilities/isec-0022-pagefault.txt
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/

stackgrow2.c