// https://syzkaller.appspot.com/bug?id=dc97f16ddcff809e6665c1607e165b3a5ce734f4
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.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>

static unsigned long long procid;

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 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"},
      {"/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)
    ;
}

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] = {0x0, 0xffffffffffffffff, 0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  memcpy((void*)0x400000000300, "./bus\000", 6);
  syscall(__NR_mkdir, /*path=*/0x400000000300ul, /*mode=S_IXUSR*/ 0x40ul);
  memcpy((void*)0x400000000100, "syz\000", 4);
  memcpy((void*)0x400000000380, "./bus\000", 6);
  memcpy((void*)0x4000000003c0, "9p\000", 3);
  syscall(__NR_mount, /*src=*/0x400000000100ul, /*dst=*/0x400000000380ul,
          /*type=*/0x4000000003c0ul,
          /*flags=MS_I_VERSION|MS_POSIXACL|MS_REC|MS_NODEV*/ 0x814004ul,
          /*opts=*/0ul);
  memcpy((void*)0x400000000140, "./bus\000", 6);
  syscall(__NR_chdir, /*dir=*/0x400000000140ul);
  res = syscall(__NR_io_setup, /*n=*/1, /*ctx=*/0x4000000004c0ul);
  if (res != -1)
    r[0] = *(uint64_t*)0x4000000004c0;
  memcpy((void*)0x400000000080, "./file0\000", 8);
  res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x400000000080ul,
                /*flags=O_SYNC|O_CREAT|O_RDWR*/ 0x101042, /*mode=*/0);
  if (res != -1)
    r[1] = res;
  memcpy((void*)0x400000000180, "./file0\000", 8);
  res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x400000000180ul,
                /*flags=O_APPEND|O_WRONLY*/ 0x401, /*mode=*/0);
  if (res != -1)
    r[2] = res;
  syscall(__NR_write, /*fd=*/r[2], /*arg=*/0ul, /*len=*/0x27ul);
  *(uint64_t*)0x4000000002c0 = 0x400000000300;
  *(uint64_t*)0x400000000300 = 0xffffff7f00000000;
  *(uint32_t*)0x400000000308 = 0;
  *(uint32_t*)0x40000000030c = 0;
  *(uint16_t*)0x400000000310 = 0;
  *(uint16_t*)0x400000000312 = 0;
  *(uint32_t*)0x400000000314 = r[1];
  *(uint64_t*)0x400000000318 = 0x4000000001c0;
  memset((void*)0x4000000001c0, 186, 1);
  *(uint64_t*)0x400000000320 = 1;
  *(uint64_t*)0x400000000328 = 0xff010000;
  *(uint64_t*)0x400000000330 = 0;
  *(uint32_t*)0x400000000338 = 0;
  *(uint32_t*)0x40000000033c = -1;
  syscall(__NR_io_submit, /*ctx=*/r[0], /*nr=*/1ul,
          /*iocbpp=*/0x4000000002c0ul);
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x3ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x400000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x400001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/-1,
          /*offset=*/0ul);
  setup_sysctl();
  const char* reason;
  (void)reason;
  for (procid = 0; procid < 4; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}