// https://syzkaller.appspot.com/bug?id=ae28a692910f2e066889b98c890adc67d88a4fda
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <sys/types.h>

#include <dirent.h>
#include <errno.h>
#include <pwd.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/endian.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

static unsigned long long procid;

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 (sig == SIGBUS)
    valid = 1;
  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_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 kill_and_wait(int pid, int* status)
{
  kill(pid, SIGKILL);
  while (waitpid(-1, status, 0) != pid) {
  }
}

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 use_temporary_dir(void)
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    exit(1);
  if (chmod(tmpdir, 0777))
    exit(1);
  if (chdir(tmpdir))
    exit(1);
}

static void reset_flags(const char* filename)
{
  struct stat st;
  if (lstat(filename, &st))
    exit(1);
  st.st_flags &= ~(SF_NOUNLINK | UF_NOUNLINK | SF_IMMUTABLE | UF_IMMUTABLE |
                   SF_APPEND | UF_APPEND);
  if (lchflags(filename, st.st_flags))
    exit(1);
}
static void __attribute__((noinline)) remove_dir(const char* dir)
{
  DIR* dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EACCES) {
      if (rmdir(dir))
        exit(1);
      return;
    }
    exit(1);
  }
  struct dirent* ep = 0;
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    struct stat st;
    if (lstat(filename, &st))
      exit(1);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    if (unlink(filename)) {
      if (errno == EPERM) {
        reset_flags(filename);
        reset_flags(dir);
        if (unlink(filename) == 0)
          continue;
      }
      exit(1);
    }
  }
  closedir(dp);
  while (rmdir(dir)) {
    if (errno == EPERM) {
      reset_flags(dir);
      if (rmdir(dir) == 0)
        break;
    }
    exit(1);
  }
}

static void execute_one(void);

#define WAIT_FLAGS 0

static void loop(void)
{
  int iter = 0;
  for (;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      if (chdir(cwdbuf))
        exit(1);
      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;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  //  openat$ptmx arguments: [
  //    fd: const = 0xffffffffffffff9c (8 bytes)
  //    file: ptr[in, buffer] {
  //      buffer: {2f 64 65 76 2f 70 66 00} (length 0x8)
  //    }
  //    flags: open_flags = 0x8 (8 bytes)
  //    mode: const = 0x0 (8 bytes)
  //  ]
  //  returns fd_pf
  NONFAILING(memcpy((void*)0x200000000000, "/dev/pf\000", 8));
  syscall(SYS_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000000ul,
          /*flags=O_APPEND*/ 8ul, /*mode=*/0ul);
  //  mprotect arguments: [
  //    addr: VMA[0x800000]
  //    len: len = 0x800000 (8 bytes)
  //    prot: mmap_prot = 0x5 (8 bytes)
  //  ]
  syscall(SYS_mprotect, /*addr=*/0x200000000000ul, /*len=*/0x800000ul,
          /*prot=PROT_READ|PROT_EXEC*/ 5ul);
  //  socket$inet6_udp arguments: [
  //    domain: const = 0x1c (8 bytes)
  //    type: const = 0x2 (8 bytes)
  //    proto: const = 0x0 (1 bytes)
  //  ]
  //  returns sock_udp6
  res = syscall(SYS_socket, /*domain=*/0x1cul, /*type=*/2ul, /*proto=*/0);
  if (res != -1)
    r[0] = res;
  //  setsockopt$inet6_IPV6_DSTOPTS arguments: [
  //    fd: sock_in6 (resource)
  //    level: const = 0x29 (4 bytes)
  //    optname: const = 0x32 (4 bytes)
  //    optval: ptr[inout, array[ANYUNION]] {
  //      array[ANYUNION] {
  //      }
  //    }
  //    optlen: len = 0x8 (8 bytes)
  //  ]
  syscall(SYS_setsockopt, /*fd=*/r[0], /*level=*/0x29, /*optname=*/0x32,
          /*optval=*/0x200000000300ul, /*optlen=*/8ul);
  //  getsockopt$inet6_buf arguments: [
  //    fd: sock_in6 (resource)
  //    level: const = 0x29 (4 bytes)
  //    optname: inet6_option_types_buf = 0x32 (4 bytes)
  //    optval: ptr[out, buffer] {
  //      buffer: (DirOut)
  //    }
  //    optlen: ptr[inout, len] {
  //      len = 0x1000 (4 bytes)
  //    }
  //  ]
  NONFAILING(*(uint32_t*)0x200000000000 = 0x1000);
  syscall(SYS_getsockopt, /*fd=*/r[0], /*level=*/0x29,
          /*optname=IPV6_DSTOPTS*/ 0x32, /*optval=*/0x200000001040ul,
          /*optlen=*/0x200000000000ul);
}
int main(void)
{
  syscall(SYS_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x1012ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  const char* reason;
  (void)reason;
  install_segv_handler();
  for (procid = 0; procid < 4; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      loop();
    }
  }
  sleep(1000000);
  return 0;
}