// https://syzkaller.appspot.com/bug?id=f358c0404db7f6b6041bf20c856da72aa72b2491
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/futex.h>

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;
  }
}

static bool write_file(const char* file, const char* what, ...)
{
  char buf[1024];
  va_list args;
  va_start(args, what);
  vsnprintf(buf, sizeof(buf), what, args);
  va_end(args);
  buf[sizeof(buf) - 1] = 0;
  int len = strlen(buf);
  int fd = open(file, O_WRONLY | O_CLOEXEC);
  if (fd == -1)
    return false;
  if (write(fd, buf, len) != len) {
    int err = errno;
    close(fd);
    errno = err;
    return false;
  }
  close(fd);
  return true;
}

static void kill_and_wait(int pid, int* status)
{
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  for (int i = 0; i < 100; i++) {
    if (waitpid(-1, status, WNOHANG | __WALL) == pid)
      return;
    usleep(1000);
  }
  DIR* dir = opendir("/sys/fs/fuse/connections");
  if (dir) {
    for (;;) {
      struct dirent* ent = readdir(dir);
      if (!ent)
        break;
      if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
        continue;
      char abort[300];
      snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort",
               ent->d_name);
      int fd = open(abort, O_WRONLY);
      if (fd == -1) {
        continue;
      }
      if (write(fd, abort, 1) < 0) {
      }
      close(fd);
    }
    closedir(dir);
  } else {
  }
  while (waitpid(-1, status, __WALL) != pid) {
  }
}

static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  write_file("/proc/self/oom_score_adj", "1000");
}

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 execute_one(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);
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      sleep_ms(10);
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

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

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    //  mkdir arguments: [
    //    path: ptr[in, buffer] {
    //      buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8)
    //    }
    //    mode: open_mode = 0x0 (8 bytes)
    //  ]
    memcpy((void*)0x200000000040, "./file0\000", 8);
    syscall(__NR_mkdir, /*path=*/0x200000000040ul, /*mode=*/0ul);
    break;
  case 1:
    //  pipe2$9p arguments: [
    //    pipefd: ptr[out, pipe_9p] {
    //      pipe_9p {
    //        rfd: rfd9p (resource)
    //        wfd: wfd9p (resource)
    //      }
    //    }
    //    flags: pipe_flags = 0x0 (8 bytes)
    //  ]
    res = syscall(__NR_pipe2, /*pipefd=*/0x200000000240ul, /*flags=*/0ul);
    if (res != -1) {
      r[0] = *(uint32_t*)0x200000000240;
      r[1] = *(uint32_t*)0x200000000244;
    }
    break;
  case 2:
    //  write$P9_RVERSION arguments: [
    //    fd: wfd9p (resource)
    //    data: ptr[inout, array[ANYUNION]] {
    //      array[ANYUNION] {
    //        union ANYUNION {
    //          ANYBLOB: buffer: {15 00 00 00 65 ff ff 09 7b 00 00 08 00 39 50
    //          32 30 30 30 2e 4c} (length 0x15)
    //        }
    //      }
    //    }
    //    size: bytesize = 0x15 (8 bytes)
    //  ]
    memcpy((void*)0x200000000480,
           "\x15\x00\x00\x00\x65\xff\xff\x09\x7b\x00\x00\x08\x00\x39\x50\x32"
           "\x30\x30\x30\x2e\x4c",
           21);
    syscall(__NR_write, /*fd=*/r[1], /*data=*/0x200000000480ul,
            /*size=*/0x15ul);
    break;
  case 3:
    //  dup arguments: [
    //    oldfd: fd (resource)
    //  ]
    //  returns fd
    res = syscall(__NR_dup, /*oldfd=*/r[1]);
    if (res != -1)
      r[2] = res;
    break;
  case 4:
    //  write$FUSE_BMAP arguments: [
    //    fd: fd_fuse (resource)
    //    arg: ptr[in, fuse_out_t[fuse_unique, fuse_bmap_out]] {
    //      fuse_out_t[fuse_unique, fuse_bmap_out] {
    //        len: len = 0x18 (4 bytes)
    //        err: fuse_errors = 0x0 (4 bytes)
    //        unique: fuse_unique (resource)
    //        payload: fuse_bmap_out {
    //          block: int64 = 0x0 (8 bytes)
    //        }
    //      }
    //    }
    //    len: bytesize = 0x18 (8 bytes)
    //  ]
    *(uint32_t*)0x200000000100 = 0x18;
    *(uint32_t*)0x200000000104 = 0;
    *(uint64_t*)0x200000000108 = 0;
    *(uint64_t*)0x200000000110 = 0;
    syscall(__NR_write, /*fd=*/r[2], /*arg=*/0x200000000100ul, /*len=*/0x18ul);
    break;
  case 5:
    //  write$FUSE_DIRENTPLUS arguments: [
    //    fd: fd_fuse (resource)
    //    arg: ptr[inout, array[ANYUNION]] {
    //      array[ANYUNION] {
    //        union ANYUNION {
    //          ANYBLOB: buffer: {b0} (length 0x1)
    //        }
    //        union ANYUNION {
    //          ANYRES8: ANYRES8 (resource)
    //        }
    //      }
    //    }
    //    len: bytesize = 0xb0 (8 bytes)
    //  ]
    memset((void*)0x200000000000, 176, 1);
    *(uint8_t*)0x200000000001 = r[1];
    syscall(__NR_write, /*fd=*/r[2], /*arg=*/0x200000000000ul, /*len=*/0xb0ul);
    break;
  case 6:
    //  mount$9p_fd arguments: [
    //    src: const = 0x0 (8 bytes)
    //    dst: ptr[in, buffer] {
    //      buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8)
    //    }
    //    type: ptr[in, buffer] {
    //      buffer: {39 70 00} (length 0x3)
    //    }
    //    flags: mount_flags = 0x0 (8 bytes)
    //    opts: ptr[inout, array[ANYUNION]] {
    //      array[ANYUNION] {
    //        union ANYUNION {
    //          ANYBLOB: buffer: {74 72 61 6e 73 3d 66 64 2c 72 66 64 6e 6f 3d}
    //          (length 0xf)
    //        }
    //        union ANYUNION {
    //          ANYRESHEX: ANYRES64 (resource)
    //        }
    //        union ANYUNION {
    //          ANYBLOB: buffer: {2c 77 66 64 6e 6f 3d} (length 0x7)
    //        }
    //        union ANYUNION {
    //          ANYRESHEX: ANYRES64 (resource)
    //        }
    //      }
    //    }
    //  ]
    memcpy((void*)0x200000000040, "./file0\000", 8);
    memcpy((void*)0x200000000b80, "9p\000", 3);
    memcpy((void*)0x20000000b880, "trans=fd,rfdno=", 15);
    sprintf((char*)0x20000000b88f, "0x%016llx", (long long)r[0]);
    memcpy((void*)0x20000000b8a1, ",wfdno=", 7);
    sprintf((char*)0x20000000b8a8, "0x%016llx", (long long)r[2]);
    syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000040ul,
            /*type=*/0x200000000b80ul, /*flags=*/0ul,
            /*opts=*/0x20000000b880ul);
    break;
  case 7:
    //  sync arguments: [
    //  ]
    syscall(__NR_sync);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
          /*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=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  loop();
  return 0;
}