// https://syzkaller.appspot.com/bug?id=d997388f338cad09dc321b54d51dde51f10fa817
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

static void fail(const char* msg, ...)
{
  int e = errno;
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

#define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1)

#define BITMASK_LEN_OFF(type, bf_off, bf_len)                                  \
  (type)(BITMASK_LEN(type, (bf_len)) << (bf_off))

#define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len)                      \
  if ((bf_off) == 0 && (bf_len) == 0) {                                        \
    *(type*)(addr) = (type)(val);                                              \
  } else {                                                                     \
    type new_val = *(type*)(addr);                                             \
    new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len));                     \
    new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off);          \
    *(type*)(addr) = new_val;                                                  \
  }

struct csum_inet {
  uint32_t acc;
};

static void csum_inet_init(struct csum_inet* csum)
{
  csum->acc = 0;
}

static void csum_inet_update(struct csum_inet* csum, const uint8_t* data,
                             size_t length)
{
  if (length == 0)
    return;

  size_t i;
  for (i = 0; i < length - 1; i += 2)
    csum->acc += *(uint16_t*)&data[i];

  if (length & 1)
    csum->acc += (uint16_t)data[length - 1];

  while (csum->acc > 0xffff)
    csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16);
}

static uint16_t csum_inet_digest(struct csum_inet* csum)
{
  return ~csum->acc;
}

static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf));
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setsid();

  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = 160 << 20;
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 8 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 0;
  setrlimit(RLIMIT_CORE, &rlim);

  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid < 0)
    fail("sandbox fork failed");
  if (pid)
    return pid;

  sandbox_common();
  if (unshare(CLONE_NEWNET)) {
  }

  loop();
  doexit(1);
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static int collide;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  return 0;
}

static void execute(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        if (collide && call % 2)
          break;
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 0x11, 0x100000802, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    memcpy((void*)0x20000140, "/dev/net/tun", 13);
    res = syz_open_dev(0x20000140, 0, 2);
    if (res != -1)
      r[1] = res;
    break;
  case 2:
    memcpy((void*)0x20000040,
           "\x69\x66\x62\x30\x00\xfa\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00",
           16);
    *(uint16_t*)0x20000050 = 0x4001;
    syscall(__NR_ioctl, r[1], 0x400454ca, 0x20000040);
    break;
  case 3:
    memcpy((void*)0x20000000,
           "\x69\x66\x62\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x20000010 = 0xa201;
    syscall(__NR_ioctl, r[0], 0x8914, 0x20000000);
    break;
  case 4:
    *(uint16_t*)0x20000300 = 0;
    *(uint16_t*)0x20000302 = htobe16(0x86dd);
    *(uint8_t*)0x20000304 = 1;
    *(uint8_t*)0x20000305 = 0;
    *(uint16_t*)0x20000306 = 0;
    *(uint16_t*)0x20000308 = 0;
    *(uint16_t*)0x2000030a = 0;
    *(uint16_t*)0x2000030c = 0;
    STORE_BY_BITMASK(uint8_t, 0x2000030e, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x2000030e, 6, 4, 4);
    memcpy((void*)0x2000030f, "\xb9\xf8\x56", 3);
    *(uint16_t*)0x20000312 = htobe16(8);
    *(uint8_t*)0x20000314 = 0x3a;
    *(uint8_t*)0x20000315 = 0;
    *(uint8_t*)0x20000316 = 0xfe;
    *(uint8_t*)0x20000317 = 0x80;
    *(uint8_t*)0x20000318 = 0;
    *(uint8_t*)0x20000319 = 0;
    *(uint8_t*)0x2000031a = 0;
    *(uint8_t*)0x2000031b = 0;
    *(uint8_t*)0x2000031c = 0;
    *(uint8_t*)0x2000031d = 0;
    *(uint8_t*)0x2000031e = 0;
    *(uint8_t*)0x2000031f = 0;
    *(uint8_t*)0x20000320 = 0;
    *(uint8_t*)0x20000321 = 0;
    *(uint8_t*)0x20000322 = 0;
    *(uint8_t*)0x20000323 = 0;
    *(uint8_t*)0x20000324 = 0;
    *(uint8_t*)0x20000325 = 0;
    *(uint8_t*)0x20000326 = 0;
    *(uint8_t*)0x20000327 = 0;
    *(uint8_t*)0x20000328 = 0;
    *(uint8_t*)0x20000329 = 0;
    *(uint8_t*)0x2000032a = 0;
    *(uint8_t*)0x2000032b = 0;
    *(uint8_t*)0x2000032c = 0;
    *(uint8_t*)0x2000032d = 0;
    *(uint8_t*)0x2000032e = 0;
    *(uint8_t*)0x2000032f = 0;
    *(uint8_t*)0x20000330 = -1;
    *(uint8_t*)0x20000331 = -1;
    *(uint32_t*)0x20000332 = htobe32(0x7f000001);
    *(uint16_t*)0x20000336 = htobe16(0);
    *(uint16_t*)0x20000338 = htobe16(0);
    *(uint16_t*)0x2000033a = htobe16(8);
    *(uint16_t*)0x2000033c = 0;
    struct csum_inet csum_1;
    csum_inet_init(&csum_1);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000316, 16);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000326, 16);
    uint32_t csum_1_chunk_2 = 0x8000000;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 4);
    uint32_t csum_1_chunk_3 = 0x11000000;
    csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 4);
    csum_inet_update(&csum_1, (const uint8_t*)0x20000336, 8);
    *(uint16_t*)0x2000033c = csum_inet_digest(&csum_1);
    syscall(__NR_write, r[1], 0x20000300, 0xfdea);
    break;
  }
}

void loop()
{
  execute(5);
  collide = 1;
  execute(5);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  int pid = do_sandbox_none();
  int status = 0;
  while (waitpid(pid, &status, __WALL) != pid) {
  }
  return 0;
}