// https://syzkaller.appspot.com/bug?id=9b519f4f0bcaeb000ba93389eda00310a6020abe
// 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 <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/capability.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;
  for (i = 0; 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);
}

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_RELAXED))
      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 setup_common()
{
  if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 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 = (200 << 20);
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 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);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
  typedef struct {
    const char* name;
    const char* value;
  } sysctl_t;
  static const sysctl_t sysctls[] = {
      {"/proc/sys/kernel/shmmax", "16777216"},
      {"/proc/sys/kernel/shmall", "536870912"},
      {"/proc/sys/kernel/shmmni", "1024"},
      {"/proc/sys/kernel/msgmax", "8192"},
      {"/proc/sys/kernel/msgmni", "1024"},
      {"/proc/sys/kernel/msgmnb", "1024"},
      {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
  };
  unsigned i;
  for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
    write_file(sysctls[i].name, sysctls[i].value);
}

int wait_for_loop(int pid)
{
  if (pid < 0)
    exit(1);
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static void drop_caps(void)
{
  struct __user_cap_header_struct cap_hdr = {};
  struct __user_cap_data_struct cap_data[2] = {};
  cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
  cap_hdr.pid = getpid();
  if (syscall(SYS_capget, &cap_hdr, &cap_data))
    exit(1);
  const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
  cap_data[0].effective &= ~drop;
  cap_data[0].permitted &= ~drop;
  cap_data[0].inheritable &= ~drop;
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    exit(1);
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);
  setup_common();
  sandbox_common();
  drop_caps();
  if (unshare(CLONE_NEWNET)) {
  }
  loop();
  exit(1);
}

static void kill_and_wait(int pid, int* status)
{
  kill(-pid, SIGKILL);
  kill(pid, SIGKILL);
  int i;
  for (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");
}

static void close_fds()
{
  int fd;
  for (fd = 3; fd < 30; fd++)
    close(fd);
}

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)
{
  int i, call, thread;
  int collide = 0;
again:
  for (call = 0; call < 6; 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 (collide && (call % 2) == 0)
        break;
      event_timedwait(&th->done, 45);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
  close_fds();
  if (!collide) {
    collide = 1;
    goto again;
  }
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter;
  for (iter = 0;; 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 (;;) {
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      sleep_ms(1);
      if (current_time_ms() - start < 5 * 1000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res;
  switch (call) {
  case 0:
    res = syscall(__NR_socket, 0x2000000000000021, 2, 2);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    *(uint16_t*)0x20000040 = 0x21;
    *(uint16_t*)0x20000042 = 0;
    *(uint16_t*)0x20000044 = 2;
    *(uint16_t*)0x20000046 = 0x10;
    *(uint16_t*)0x20000048 = 2;
    *(uint16_t*)0x2000004a = htobe16(0);
    *(uint8_t*)0x2000004c = 0xac;
    *(uint8_t*)0x2000004d = 0x14;
    *(uint8_t*)0x2000004e = 0x14;
    *(uint8_t*)0x2000004f = 0xbb;
    syscall(__NR_connect, r[0], 0x20000040, 0x24);
    break;
  case 2:
    *(uint64_t*)0x20005c00 = 0;
    *(uint32_t*)0x20005c08 = 0;
    *(uint64_t*)0x20005c10 = 0;
    *(uint64_t*)0x20005c18 = 0;
    *(uint64_t*)0x20005c20 = 0x200003c0;
    memcpy((void*)0x200003c0,
           "\x18\x00\x00\x00\x00\x00\x00\x00\x10\x01\x00\x00\x01\x00\x00\x00"
           "\x77\x00\x00\x00\x0b\xdf\x00\x40\x93\x30\xb3\xe7\xd8\xed\x12\x7c"
           "\xaa\x87\xf7\x54\x78\x75\x92\x07\xd1\x06\x04\xec\x95\xff\x7b\xcb"
           "\x0d\x6b\x9b\x12\x5e\xc8\x5a\x36\x6a\xbe\x4f\x50\x11\x1f\x0a\x03"
           "\xdb\xd1\xb4\xde\xa0\x5a\x8b\x5b\x29\xe8\x4e\x4f\xad\xaa\x6e\xbe"
           "\x73\x64\x27\xe4\x4d\xc6\x50\x5d\x24\x23\x48\x26\xa2\x67\xf7\x5c"
           "\x74\x3d\xb9\x65\x04\x1c\x09\xc5\x90\x47\xf7\xf7\x94\xfd\xff\xff"
           "\x80\xb6\xd7\x24\xc8\xf3\x56\xb5\xc2\x8a\xff\xff\xff\xff\xff\x81"
           "\x93\xb1\xa5\xc3\x43\x84\x95\xd9\x29\xce\x2f\x1a\xe8\x93\xaf\xaf"
           "\x3f\x05\xd3\x2d\x0b\xfa\x67\xb3\xda\x43\xab\x98\x13\x13\xe7\x55"
           "\x22\x38\x86\xb1\x80\xa2\x69\x91\x7d\xb5\x43\x0e\xf9\xae\xc0\x71"
           "\xe4\x4c\xd1\x9c\xb1\x8e\x4e\x05\x28\xac\xd1\x34\x71\xf4\x4d\x80"
           "\xd2\x1e\xd5\xde\x4b\x4c\xa3\x1f\x42\x69\xa8\x81\x15\xbe\xce\x67"
           "\x6d\x0f\xbf\x16\x5b\x08\xc3\x51\x78\xe5\x98\x93\x79\xcc\x9d\xf9"
           "\xe1\x21\xa9\x57\x31\xd0\x88\xd6",
           232);
    *(uint64_t*)0x20005c28 = 0x18;
    *(uint32_t*)0x20005c30 = 0;
    *(uint32_t*)0x20005c38 = 0;
    syscall(__NR_sendmmsg, r[0], 0x20005c00, 1, 0);
    break;
  case 3:
    *(uint64_t*)0x20005c00 = 0;
    *(uint32_t*)0x20005c08 = 0xfffffd95;
    *(uint64_t*)0x20005c10 = 0;
    *(uint64_t*)0x20005c18 = 0;
    *(uint64_t*)0x20005c20 = 0x20000000;
    *(uint64_t*)0x20000000 = 0x18;
    *(uint32_t*)0x20000008 = 0x110;
    *(uint32_t*)0x2000000c = 1;
    memcpy((void*)0x20000010, "\xec", 1);
    *(uint64_t*)0x20005c28 = 0x18;
    *(uint32_t*)0x20005c30 = 0;
    *(uint32_t*)0x20005c38 = 0;
    syscall(__NR_sendmmsg, r[0], 0x20005c00, 1, 0);
    break;
  case 4:
    res = syscall(__NR_socket, 0x10, 3, 6);
    if (res != -1)
      r[1] = res;
    break;
  case 5:
    *(uint32_t*)0x20000180 = 0;
    syscall(__NR_getsockopt, r[1], 1, 0x1e, 0, 0x20000180);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  do_sandbox_none();
  return 0;
}