// https://syzkaller.appspot.com/bug?id=0d5a5186a23374a7ae64be07329712bfe16bb1fc
// 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 <setjmp.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/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 __thread int clone_ongoing;
static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) {
    exit(sig);
  }
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0;
  int valid = addr < prog_start || addr > prog_end;
  if (skip && valid) {
    _longjmp(segv_env, 1);
  }
  exit(sig);
}

static void install_segv_handler(void)
{
  struct sigaction sa;
  memset(&sa, 0, sizeof(sa));
  sa.sa_handler = SIG_IGN;
  syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8);
  syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8);
  memset(&sa, 0, sizeof(sa));
  sa.sa_sigaction = segv_handler;
  sa.sa_flags = SA_NODEFER | SA_SIGINFO;
  sigaction(SIGSEGV, &sa, NULL);
  sigaction(SIGBUS, &sa, NULL);
}

#define NONFAILING(...)                                                        \
  ({                                                                           \
    int ok = 1;                                                                \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    } else                                                                     \
      ok = 0;                                                                  \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    ok;                                                                        \
  })

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");
}

static void setup_sysctl()
{
  int cad_pid = fork();
  if (cad_pid < 0)
    exit(1);
  if (cad_pid == 0) {
    for (;;)
      sleep(100);
  }
  char tmppid[32];
  snprintf(tmppid, sizeof(tmppid), "%d", cad_pid);
  struct {
    const char* name;
    const char* data;
  } files[] = {
      {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"},
      {"/proc/sys/kernel/hung_task_check_interval_secs", "20"},
      {"/proc/sys/net/core/bpf_jit_kallsyms", "1"},
      {"/proc/sys/net/core/bpf_jit_harden", "0"},
      {"/proc/sys/kernel/kptr_restrict", "0"},
      {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"},
      {"/proc/sys/fs/mount-max", "100"},
      {"/proc/sys/vm/oom_dump_tasks", "0"},
      {"/proc/sys/debug/exception-trace", "0"},
      {"/proc/sys/kernel/printk", "7 4 1 3"},
      {"/proc/sys/kernel/keys/gc_delay", "1"},
      {"/proc/sys/vm/oom_kill_allocating_task", "1"},
      {"/sys/kernel/debug/failslab/task-filter", "Y"},
      {"/sys/kernel/debug/fail_page_alloc/task-filter", "Y"},
      {"/sys/kernel/debug/fail_futex/task-filter", "Y"},
      {"/sys/kernel/debug/fail_usercopy/task-filter", "Y"},
      {"/sys/kernel/debug/fail_make_request/task-filter", "Y"},
      {"/sys/kernel/debug/fail_io_timeout/task-filter", "Y"},
      {"/sys/kernel/debug/fail_iommufd/task-filter", "Y"},
      {"/proc/sys/kernel/ctrl-alt-del", "0"},
      {"/proc/sys/kernel/cad_pid", tmppid},
  };
  for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].name, files[i].data)) {
    }
  }
  kill(cad_pid, SIGKILL);
  while (waitpid(cad_pid, NULL, 0) != cad_pid)
    ;
}

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 < 7; 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:
    //  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=*/0x200000000280ul, /*flags=*/0ul);
    for (int i = 0; i < 32; i++) {
      syscall(__NR_pipe2, /*pipefd=*/0x200000000280ul, /*flags=*/0ul);
    }
    if (res != -1) {
      NONFAILING(r[0] = *(uint32_t*)0x200000000280);
      NONFAILING(r[1] = *(uint32_t*)0x200000000284);
    }
    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=*/0x200000000c00ul, /*flags=*/0ul);
    if (res != -1)
      NONFAILING(r[2] = *(uint32_t*)0x200000000c04);
    break;
  case 2:
    //  mkdirat arguments: [
    //    fd: fd_dir (resource)
    //    path: ptr[in, buffer] {
    //      buffer: {2e 2f 6d 6e 74 00} (length 0x6)
    //    }
    //    mode: open_mode = 0x1ff (8 bytes)
    //  ]
    NONFAILING(memcpy((void*)0x200000000c40, "./mnt\000", 6));
    syscall(
        __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x200000000c40ul,
        /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/
        0x1fful);
    break;
  case 3:
    //  mount$9p_fd arguments: [
    //    src: const = 0x0 (8 bytes)
    //    dst: ptr[in, buffer] {
    //      buffer: {2e 2f 6d 6e 74 00} (length 0x6)
    //    }
    //    type: ptr[in, buffer] {
    //      buffer: {39 70 00} (length 0x3)
    //    }
    //    flags: mount_flags = 0x0 (8 bytes)
    //    opts: ptr[in, p9_options_fd] {
    //      p9_options_fd {
    //        trans: buffer: {74 72 61 6e 73 3d 66 64 2c} (length 0x9)
    //        rfdno: fs_opt["rfdno", fmt[hex, rfd9p]] {
    //          name: buffer: {72 66 64 6e 6f} (length 0x5)
    //          eq: const = 0x3d (1 bytes)
    //          val: rfd9p (resource)
    //        }
    //        comma0: const = 0x2c (1 bytes)
    //        wfdno: fs_opt["wfdno", fmt[hex, fd]] {
    //          name: buffer: {77 66 64 6e 6f} (length 0x5)
    //          eq: const = 0x3d (1 bytes)
    //          val: fd (resource)
    //        }
    //        comma1: const = 0x2c (1 bytes)
    //        opts: fs_options[p9_options] {
    //          elems: array[fs_opt_elem[p9_options]] {
    //          }
    //          common: array[fs_opt_elem[fs_options_common]] {
    //          }
    //          null: const = 0x0 (1 bytes)
    //        }
    //      }
    //    }
    //  ]
    NONFAILING(memcpy((void*)0x200000000c80, "./mnt\000", 6));
    NONFAILING(memcpy((void*)0x200000000cc0, "9p\000", 3));
    NONFAILING(memcpy((void*)0x200000000d00, "trans=fd,", 9));
    NONFAILING(memcpy((void*)0x200000000d09, "rfdno", 5));
    NONFAILING(*(uint8_t*)0x200000000d0e = 0x3d);
    NONFAILING(sprintf((char*)0x200000000d0f, "0x%016llx", (long long)r[0]));
    NONFAILING(*(uint8_t*)0x200000000d21 = 0x2c);
    NONFAILING(memcpy((void*)0x200000000d22, "wfdno", 5));
    NONFAILING(*(uint8_t*)0x200000000d27 = 0x3d);
    NONFAILING(sprintf((char*)0x200000000d28, "0x%016llx", (long long)r[2]));
    NONFAILING(*(uint8_t*)0x200000000d3a = 0x2c);
    NONFAILING(*(uint8_t*)0x200000000d3b = 0);
    syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000c80ul,
            /*type=*/0x200000000cc0ul, /*flags=*/0ul,
            /*opts=*/0x200000000d00ul);
    break;
  case 4:
    //  write$P9_RVERSION arguments: [
    //    fd: wfd9p (resource)
    //    data: ptr[in, p9_rversion] {
    //      p9_rversion {
    //        size: bytesize = 0x15 (4 bytes)
    //        type: const = 0x65 (1 bytes)
    //        tag: const = 0xffff (2 bytes)
    //        msize: int32 = 0x42000 (4 bytes)
    //        version_len: len = 0x8 (2 bytes)
    //        version: buffer: {39 50 32 30 30 30 2e 4c} (length 0x8)
    //      }
    //    }
    //    size: bytesize = 0x15 (8 bytes)
    //  ]
    NONFAILING(*(uint32_t*)0x200000000d40 = 0x15);
    NONFAILING(*(uint8_t*)0x200000000d44 = 0x65);
    NONFAILING(*(uint16_t*)0x200000000d45 = -1);
    NONFAILING(*(uint32_t*)0x200000000d47 = 0x42000);
    NONFAILING(*(uint16_t*)0x200000000d4b = 8);
    NONFAILING(memcpy((void*)0x200000000d4d, "9P2000.L", 8));
    syscall(__NR_write, /*fd=*/r[1], /*data=*/0x200000000d40ul,
            /*size=*/0x15ul);
    break;
  case 5:
    //  write$P9_RGETATTR arguments: [
    //    fd: wfd9p (resource)
    //    data: ptr[in, p9_msg[P9_RGETATTR, p9_rgetattr]] {
    //      p9_msg[P9_RGETATTR, p9_rgetattr] {
    //        size: bytesize = 0xa0 (4 bytes)
    //        type: const = 0x19 (1 bytes)
    //        tag: int16 = 0x0 (2 bytes)
    //        payload: p9_rgetattr {
    //          valid: p8_stats_valid = 0x38b5 (8 bytes)
    //          qid: p9_qid {
    //            type: p9_qid_types = 0x40 (1 bytes)
    //            version: int32 = 0x2 (4 bytes)
    //            path: int64 = 0x3 (8 bytes)
    //          }
    //          mode: open_mode = 0x40 (4 bytes)
    //          uid: uid (resource)
    //          gid: gid (resource)
    //          nlink: int64 = 0x0 (8 bytes)
    //          rdev: int64 = 0xae (8 bytes)
    //          size: int64 = 0xa (8 bytes)
    //          blksize: int64 = 0x4 (8 bytes)
    //          blocks: int64 = 0x8 (8 bytes)
    //          atime_sec: int64 = 0x0 (8 bytes)
    //          atime_nsec: int64 = 0x0 (8 bytes)
    //          mtime_sec: int64 = 0x0 (8 bytes)
    //          mtime_nsec: int64 = 0x0 (8 bytes)
    //          ctime_sec: int64 = 0x0 (8 bytes)
    //          ctime_nsec: int64 = 0x0 (8 bytes)
    //          btime_sec: int64 = 0xffffffffffffffff (8 bytes)
    //          btime_nsec: int64 = 0x7fffffffffffffff (8 bytes)
    //          gen: int64 = 0xfffffffffffffffc (8 bytes)
    //          data_version: int64 = 0x3 (8 bytes)
    //        }
    //      }
    //    }
    //    size: bytesize = 0xa0 (8 bytes)
    //  ]
    NONFAILING(*(uint32_t*)0x200000000d80 = 0xa0);
    NONFAILING(*(uint8_t*)0x200000000d84 = 0x19);
    NONFAILING(*(uint16_t*)0x200000000d85 = 0);
    NONFAILING(*(uint64_t*)0x200000000d87 = 0x38b5);
    NONFAILING(*(uint8_t*)0x200000000d8f = 0x40);
    NONFAILING(*(uint32_t*)0x200000000d90 = 2);
    NONFAILING(*(uint64_t*)0x200000000d94 = 3);
    NONFAILING(*(uint32_t*)0x200000000d9c = 0x40);
    NONFAILING(*(uint32_t*)0x200000000da0 = 0);
    NONFAILING(*(uint32_t*)0x200000000da4 = -1);
    NONFAILING(*(uint64_t*)0x200000000da8 = 0);
    NONFAILING(*(uint64_t*)0x200000000db0 = 0xae);
    NONFAILING(*(uint64_t*)0x200000000db8 = 0xa);
    NONFAILING(*(uint64_t*)0x200000000dc0 = 4);
    NONFAILING(*(uint64_t*)0x200000000dc8 = 8);
    NONFAILING(*(uint64_t*)0x200000000dd0 = 0);
    NONFAILING(*(uint64_t*)0x200000000dd8 = 0);
    NONFAILING(*(uint64_t*)0x200000000de0 = 0);
    NONFAILING(*(uint64_t*)0x200000000de8 = 0);
    NONFAILING(*(uint64_t*)0x200000000df0 = 0);
    NONFAILING(*(uint64_t*)0x200000000df8 = 0);
    NONFAILING(*(uint64_t*)0x200000000e00 = -1);
    NONFAILING(*(uint64_t*)0x200000000e08 = 0x7fffffffffffffff);
    NONFAILING(*(uint64_t*)0x200000000e10 = 0xfffffffffffffffc);
    NONFAILING(*(uint64_t*)0x200000000e18 = 3);
    syscall(__NR_write, /*fd=*/r[1], /*data=*/0x200000000d80ul,
            /*size=*/0xa0ul);
    break;
  case 6:
    //  sync arguments: [
    //  ]
    syscall(__NR_sync);
    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);
  setup_sysctl();
  const char* reason;
  (void)reason;
  install_segv_handler();
  loop();
  return 0;
}