// https://syzkaller.appspot.com/bug?id=5735d842f7ea3ed9220aca64952ac4aba7ba741c
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <fcntl.h>
#include <linux/futex.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/sysmacros.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 <stdlib.h>
#include <string.h>
#include <sys/stat.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 void use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

static uintptr_t syz_fuse_mount(uintptr_t a0, uintptr_t a1, uintptr_t a2,
                                uintptr_t a3, uintptr_t a4, uintptr_t a5)
{
  uint64_t target = a0;
  uint64_t mode = a1;
  uint64_t uid = a2;
  uint64_t gid = a3;
  uint64_t maxread = a4;
  uint64_t flags = a5;

  int fd = open("/dev/fuse", O_RDWR);
  if (fd == -1)
    return fd;
  char buf[1024];
  sprintf(buf, "fd=%d,user_id=%ld,group_id=%ld,rootmode=0%o", fd, (long)uid,
          (long)gid, (unsigned)mode & ~3u);
  if (maxread != 0)
    sprintf(buf + strlen(buf), ",max_read=%ld", (long)maxread);
  if (mode & 1)
    strcat(buf, ",default_permissions");
  if (mode & 2)
    strcat(buf, ",allow_other");
  syscall(SYS_mount, "", target, "fuse", flags, buf);
  return fd;
}

static void execute_one();
extern unsigned long long procid;

void loop()
{
  while (1) {
    execute_one();
  }
}

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[1] = {0xffffffffffffffff};
unsigned long long procid;
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 2, 2, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    *(uint32_t*)0x20000000 = 1;
    memcpy((void*)0x20000004,
           "\x73\x79\x7a\x5f\x74\x75\x6e\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint32_t*)0x20000014 = 0;
    syscall(__NR_setsockopt, r[0], 0, 0x48b, 0x20000000, 0x18);
    break;
  case 2:
    *(uint32_t*)0x20000100 = 1;
    memcpy((void*)0x20000104,
           "\x69\x72\x6c\x61\x6e\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint32_t*)0x20000114 = 0;
    syscall(__NR_setsockopt, r[0], 0, 0x48c, 0x20000100, 0x18);
    break;
  case 3:
    *(uint8_t*)0x200000c0 = 0xaa;
    *(uint8_t*)0x200000c1 = 0xaa;
    *(uint8_t*)0x200000c2 = 0xaa;
    *(uint8_t*)0x200000c3 = 0xaa;
    *(uint8_t*)0x200000c4 = 0xaa;
    *(uint8_t*)0x200000c5 = 0xaa;
    *(uint8_t*)0x200000c6 = 1;
    *(uint8_t*)0x200000c7 = 0x80;
    *(uint8_t*)0x200000c8 = 0xc2;
    *(uint8_t*)0x200000c9 = 0;
    *(uint8_t*)0x200000ca = 0;
    *(uint8_t*)0x200000cb = 0;
    *(uint16_t*)0x200000cc = htobe16(0x800);
    STORE_BY_BITMASK(uint8_t, 0x200000ce, 5, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x200000ce, 4, 4, 4);
    STORE_BY_BITMASK(uint8_t, 0x200000cf, 0, 0, 2);
    STORE_BY_BITMASK(uint8_t, 0x200000cf, 0, 2, 6);
    *(uint16_t*)0x200000d0 = htobe16(0x58);
    *(uint16_t*)0x200000d2 = htobe16(0);
    *(uint16_t*)0x200000d4 = htobe16(0);
    *(uint8_t*)0x200000d6 = 0;
    *(uint8_t*)0x200000d7 = 0x2f;
    *(uint16_t*)0x200000d8 = 0;
    *(uint8_t*)0x200000da = 0xac;
    *(uint8_t*)0x200000db = 0x14;
    *(uint8_t*)0x200000dc = -1;
    *(uint8_t*)0x200000dd = 0xaa;
    *(uint32_t*)0x200000de = htobe32(-1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 0, 0, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 0, 1, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 1, 2, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 0, 3, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 0xb, 4, 4);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, -1, 8, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 0, 9, 4);
    STORE_BY_BITMASK(uint16_t, 0x200000e2, 8, 13, 3);
    *(uint16_t*)0x200000e4 = htobe16(0x880b);
    *(uint16_t*)0x200000e6 = htobe16(0);
    *(uint16_t*)0x200000e8 = htobe16(0);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 0, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 1, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 2, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 3, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 4, 9);
    STORE_BY_BITMASK(uint16_t, 0x200000ea, 0, 13, 3);
    *(uint16_t*)0x200000ec = htobe16(0x800);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 0, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 1, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 2, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 3, 1);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 4, 9);
    STORE_BY_BITMASK(uint16_t, 0x200000ee, 0, 13, 3);
    *(uint16_t*)0x200000f0 = htobe16(0x86dd);
    *(uint16_t*)0x200000f2 = 0;
    *(uint16_t*)0x200000f4 = htobe16(0x21);
    *(uint32_t*)0x200000f6 = htobe32(0);
    STORE_BY_BITMASK(uint8_t, 0x200000fa, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x200000fa, 0, 4, 4);
    *(uint8_t*)0x200000fb = 0;
    STORE_BY_BITMASK(uint8_t, 0x200000fc, 0, 0, 2);
    STORE_BY_BITMASK(uint8_t, 0x200000fc, 0, 2, 1);
    STORE_BY_BITMASK(uint8_t, 0x200000fc, 0, 3, 2);
    STORE_BY_BITMASK(uint8_t, 0x200000fc, 0, 5, 3);
    *(uint8_t*)0x200000fd = 0;
    *(uint32_t*)0x200000fe = 0;
    *(uint32_t*)0x20000102 = htobe32(0);
    *(uint16_t*)0x20000106 = 0;
    *(uint16_t*)0x20000108 = htobe16(0);
    *(uint32_t*)0x2000010a = htobe32(0);
    STORE_BY_BITMASK(uint8_t, 0x2000010e, 0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x2000010e, 0, 4, 4);
    *(uint8_t*)0x2000010f = 0;
    STORE_BY_BITMASK(uint8_t, 0x20000110, 0, 0, 2);
    STORE_BY_BITMASK(uint8_t, 0x20000110, 0, 2, 1);
    STORE_BY_BITMASK(uint8_t, 0x20000110, 0, 3, 2);
    STORE_BY_BITMASK(uint8_t, 0x20000110, 0, 5, 3);
    *(uint8_t*)0x20000111 = 0;
    *(uint32_t*)0x20000112 = 0;
    *(uint32_t*)0x20000116 = htobe32(0);
    *(uint16_t*)0x2000011a = htobe16(0);
    STORE_BY_BITMASK(uint8_t, 0x2000011c, 0, 0, 2);
    STORE_BY_BITMASK(uint8_t, 0x2000011c, 0, 2, 5);
    STORE_BY_BITMASK(uint8_t, 0x2000011c, 0, 7, 1);
    STORE_BY_BITMASK(uint8_t, 0x2000011d, 0, 0, 1);
    STORE_BY_BITMASK(uint8_t, 0x2000011d, 0, 1, 2);
    STORE_BY_BITMASK(uint8_t, 0x2000011d, 0, 3, 1);
    STORE_BY_BITMASK(uint8_t, 0x2000011d, 0, 4, 1);
    *(uint16_t*)0x2000011e = 0;
    *(uint16_t*)0x20000120 = htobe16(0);
    *(uint32_t*)0x20000122 = htobe32(0);
    struct csum_inet csum_1;
    csum_inet_init(&csum_1);
    csum_inet_update(&csum_1, (const uint8_t*)0x200000ce, 20);
    *(uint16_t*)0x200000d8 = csum_inet_digest(&csum_1);
    break;
  case 4:
    memcpy((void*)0x20fd5ff8, "./file0", 8);
    syscall(__NR_mkdir, 0x20fd5ff8, 0);
    break;
  case 5:
    memcpy((void*)0x20000340, "./file0", 8);
    syz_fuse_mount(0x20000340, 0x4000, 0, 0, 0, 0);
    break;
  }
}

void execute_one()
{
  execute(6);
  collide = 1;
  execute(6);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  char* cwd = get_current_dir_name();
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        if (chdir(cwd))
          fail("failed to chdir");
        use_temporary_dir();
        loop();
      }
    }
  }
  sleep(1000000);
  return 0;
}