// https://syzkaller.appspot.com/bug?id=12d2a0443c5b41cac2798aa8fcfdfa8632b852b6
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>

#ifndef __NR_seccomp
#define __NR_seccomp 317
#endif

static void sleep_ms(uint64_t ms)
{
  usleep(ms * 1000);
}

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

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

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void loop(void)
{
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  int i, call, thread;
  for (call = 0; call < 8; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      if (call == 5)
        break;
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    //  unshare arguments: [
    //    flags: unshare_flags = 0x22020600 (8 bytes)
    //  ]
    syscall(__NR_unshare,
            /*flags=CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWCGROUP|CLONE_FS|0x400*/
            0x22020600ul);
    break;
  case 1:
    //  seccomp$SECCOMP_SET_MODE_FILTER_LISTENER arguments: [
    //    op: const = 0x1 (8 bytes)
    //    flags: seccomp_flags_listener = 0x7 (8 bytes)
    //    arg: nil
    //  ]
    //  returns fd_seccomp
    syscall(__NR_seccomp, /*op=*/1ul, /*flags=*/7ul, /*arg=*/0ul);
    break;
  case 2:
    //  socket$pppl2tp arguments: [
    //    domain: const = 0x18 (8 bytes)
    //    type: const = 0x1 (8 bytes)
    //    proto: const = 0x1 (4 bytes)
    //  ]
    //  returns sock_pppl2tp
    res = syscall(__NR_socket, /*domain=*/0x18ul, /*type=*/1ul, /*proto=*/1);
    if (res != -1)
      r[0] = res;
    break;
  case 3:
    //  socket$inet6_udp arguments: [
    //    domain: const = 0xa (8 bytes)
    //    type: const = 0x2 (8 bytes)
    //    proto: const = 0x0 (4 bytes)
    //  ]
    //  returns sock_udp6
    res = syscall(__NR_socket, /*domain=*/0xaul, /*type=*/2ul, /*proto=*/0);
    if (res != -1)
      r[1] = res;
    break;
  case 4:
    //  connect$pppl2tp arguments: [
    //    fd: sock_pppl2tp (resource)
    //    addr: ptr[in, sockaddr_pppl2tp] {
    //      union sockaddr_pppl2tp {
    //        pppol2tp: sockaddr_pppl2tp_t[pppol2tp_addr] {
    //          sa_family: const = 0x18 (2 bytes)
    //          sa_protocol: const = 0x1 (4 bytes)
    //          addr: pppol2tp_addr_t[int16] {
    //            pid: const = 0x0 (4 bytes)
    //            fd: sock (resource)
    //            addr: sockaddr_in {
    //              family: const = 0x2 (2 bytes)
    //              port: int16be = 0x4e24 (2 bytes)
    //              addr: union ipv4_addr {
    //                broadcast: const = 0xffffffff (4 bytes)
    //              }
    //              pad = 0x0 (8 bytes)
    //            }
    //            s_tunnel: int16 = 0x2 (2 bytes)
    //            s_session: int16 = 0x0 (2 bytes)
    //            d_tunnel: int16 = 0x3 (2 bytes)
    //            d_session: int16 = 0x0 (2 bytes)
    //          }
    //        }
    //      }
    //    }
    //    addrlen: len = 0x26 (8 bytes)
    //  ]
    *(uint16_t*)0x200000000000 = 0x18;
    *(uint32_t*)0x200000000002 = 1;
    *(uint32_t*)0x200000000006 = 0;
    *(uint32_t*)0x20000000000a = r[1];
    *(uint16_t*)0x20000000000e = 2;
    *(uint16_t*)0x200000000010 = htobe16(0x4e24);
    *(uint32_t*)0x200000000012 = htobe32(-1);
    *(uint16_t*)0x20000000001e = 2;
    *(uint16_t*)0x200000000020 = 0;
    *(uint16_t*)0x200000000022 = 3;
    *(uint16_t*)0x200000000024 = 0;
    syscall(__NR_connect, /*fd=*/r[0], /*addr=*/0x200000000000ul,
            /*addrlen=*/0x26ul);
    break;
  case 5:
    //  openat$ppp arguments: [
    //    fd: const = 0xffffffffffffff9c (8 bytes)
    //    file: nil
    //    flags: open_flags = 0x1 (4 bytes)
    //    mode: const = 0x0 (2 bytes)
    //  ]
    //  returns fd_ppp
    syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul,
            /*flags=O_WRONLY*/ 1, /*mode=*/0);
    break;
  case 6:
    //  openat$ppp arguments: [
    //    fd: const = 0xffffffffffffff9c (8 bytes)
    //    file: ptr[in, buffer] {
    //      buffer: {2f 64 65 76 2f 70 70 70 00} (length 0x9)
    //    }
    //    flags: open_flags = 0x1 (4 bytes)
    //    mode: const = 0x0 (2 bytes)
    //  ]
    //  returns fd_ppp
    memcpy((void*)0x2000000000c0, "/dev/ppp\000", 9);
    res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul,
                  /*file=*/0x2000000000c0ul, /*flags=O_WRONLY*/ 1, /*mode=*/0);
    if (res != -1)
      r[2] = res;
    break;
  case 7:
    //  ioctl$PPPIOCATTCHAN arguments: [
    //    fd: fd_ppp (resource)
    //    cmd: const = 0x40047438 (4 bytes)
    //    arg: nil
    //  ]
    syscall(__NR_ioctl, /*fd=*/r[2], /*cmd=*/0x40047438, /*arg=*/0ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  loop();
  return 0;
}