// https://syzkaller.appspot.com/bug?id=54ed39500523ce4ae77f87c27095a4bd21447370
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.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/ioctl.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/loop.h>

static unsigned long long procid;

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _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(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

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 long syz_open_dev(volatile long a0, volatile long a1, volatile long a2)
{
  if (a0 == 0xc || a0 == 0xb) {
    char buf[128];
    sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1,
            (uint8_t)a2);
    return open(buf, O_RDWR, 0);
  } else {
    char buf[1024];
    char* hash;
    NONFAILING(strncpy(buf, (char*)a0, sizeof(buf) - 1));
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

static long syz_open_procfs(volatile long a0, volatile long a1)
{
  char buf[128];
  memset(buf, 0, sizeof(buf));
  if (a0 == 0) {
    NONFAILING(snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1));
  } else if (a0 == -1) {
    NONFAILING(snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1));
  } else {
    NONFAILING(snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0,
                        (char*)a1));
  }
  int fd = open(buf, O_RDWR);
  if (fd == -1)
    fd = open(buf, O_RDONLY);
  return fd;
}

struct fs_image_segment {
  void* data;
  uintptr_t size;
  uintptr_t offset;
};

#define IMAGE_MAX_SEGMENTS 4096
#define IMAGE_MAX_SIZE (129 << 20)

#define sys_memfd_create 319

static unsigned long fs_image_segment_check(unsigned long size,
                                            unsigned long nsegs, long segments)
{
  unsigned long i;
  struct fs_image_segment* segs = (struct fs_image_segment*)segments;
  if (nsegs > IMAGE_MAX_SEGMENTS)
    nsegs = IMAGE_MAX_SEGMENTS;
  for (i = 0; i < nsegs; i++) {
    if (segs[i].size > IMAGE_MAX_SIZE)
      segs[i].size = IMAGE_MAX_SIZE;
    segs[i].offset %= IMAGE_MAX_SIZE;
    if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size)
      segs[i].offset = IMAGE_MAX_SIZE - segs[i].size;
    if (size < segs[i].offset + segs[i].offset)
      size = segs[i].offset + segs[i].offset;
  }
  if (size > IMAGE_MAX_SIZE)
    size = IMAGE_MAX_SIZE;
  return size;
}

static long syz_mount_image(volatile long fsarg, volatile long dir,
                            volatile unsigned long size,
                            volatile unsigned long nsegs,
                            volatile long segments, volatile long flags,
                            volatile long optsarg)
{
  char loopname[64], fs[32], opts[256];
  int loopfd, err = 0, res = -1;
  unsigned long i;
  NONFAILING(size = fs_image_segment_check(size, nsegs, segments));
  int memfd = syscall(sys_memfd_create, "syz_mount_image", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (ftruncate(memfd, size)) {
    err = errno;
    goto error_close_memfd;
  }
  for (i = 0; i < nsegs; i++) {
    struct fs_image_segment* segs = (struct fs_image_segment*)segments;
    int res1 = 0;
    NONFAILING(res1 =
                   pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset));
    if (res1 < 0) {
    }
  }
  snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
  loopfd = open(loopname, O_RDWR);
  if (loopfd == -1) {
    err = errno;
    goto error_close_memfd;
  }
  if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
    if (errno != EBUSY) {
      err = errno;
      goto error_close_loop;
    }
    ioctl(loopfd, LOOP_CLR_FD, 0);
    usleep(1000);
    if (ioctl(loopfd, LOOP_SET_FD, memfd)) {
      err = errno;
      goto error_close_loop;
    }
  }
  mkdir((char*)dir, 0777);
  memset(fs, 0, sizeof(fs));
  NONFAILING(strncpy(fs, (char*)fsarg, sizeof(fs) - 1));
  memset(opts, 0, sizeof(opts));
  NONFAILING(strncpy(opts, (char*)optsarg, sizeof(opts) - 32));
  if (strcmp(fs, "iso9660") == 0) {
    flags |= MS_RDONLY;
  } else if (strncmp(fs, "ext", 3) == 0) {
    if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0)
      strcat(opts, ",errors=continue");
  } else if (strcmp(fs, "xfs") == 0) {
    strcat(opts, ",nouuid");
  }
  if (mount(loopname, (char*)dir, fs, flags, opts)) {
    err = errno;
    goto error_clear_loop;
  }
  res = 0;
error_clear_loop:
  ioctl(loopfd, LOOP_CLR_FD, 0);
error_close_loop:
  close(loopfd);
error_close_memfd:
  close(memfd);
error:
  errno = err;
  return res;
}

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 reset_loop()
{
  char buf[64];
  snprintf(buf, sizeof(buf), "/dev/loop%llu", procid);
  int loopfd = open(buf, O_RDWR);
  if (loopfd != -1) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
  }
}

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

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter;
  for (iter = 0;; iter++) {
    reset_loop();
    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[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  NONFAILING(memcpy((void*)0x200000c0, "minix\000", 6));
  NONFAILING(memcpy((void*)0x20000080, "./file0\000", 8));
  NONFAILING(*(uint64_t*)0x20000000 = 0x20000140);
  NONFAILING(memcpy((void*)0x20000140, "\x60\x00\x84\xe0\x02\x00\x0a\x00\x90"
                                       "\x0c\xda\x40\xff\x1a\xd5\xc9\x8f\x13",
                    18));
  NONFAILING(*(uint64_t*)0x20000008 = 0x12);
  NONFAILING(*(uint64_t*)0x20000010 = 0x400);
  NONFAILING(*(uint64_t*)0x20000018 = 0);
  NONFAILING(*(uint64_t*)0x20000020 = 0);
  NONFAILING(*(uint64_t*)0x20000028 = 0x34f9);
  syz_mount_image(0x200000c0, 0x20000080, 0x200000000, 2, 0x20000000, 0, 0);
  syz_open_procfs(0, 0);
  syscall(__NR_fanotify_init, 0ul, 0ul);
  syscall(__NR_open, 0ul, 0ul, 0ul);
  syscall(__NR_open, 0ul, 0x141042ul, 0ul);
  syscall(__NR_write, -1, 0ul, 0x15ul);
  syscall(__NR_perf_event_open, 0ul, 0, -1ul, -1, 0ul);
  NONFAILING(memcpy((void*)0x20000180, "/dev/loop#\000", 11));
  res = syz_open_dev(0x20000180, 0, 0x169a01);
  if (res != -1)
    r[0] = res;
  NONFAILING(*(uint64_t*)0x200001c0 = 0xa00);
  NONFAILING(*(uint64_t*)0x200001c8 = 0x60000);
  NONFAILING(*(uint64_t*)0x200001d0 = 0x6000);
  NONFAILING(*(uint64_t*)0x200001d8 = 0);
  NONFAILING(*(uint64_t*)0x200001e0 = 0);
  NONFAILING(*(uint32_t*)0x200001e8 = 0);
  NONFAILING(*(uint32_t*)0x200001ec = 0);
  NONFAILING(*(uint32_t*)0x200001f0 = 0);
  NONFAILING(*(uint32_t*)0x200001f4 = 0);
  NONFAILING(memcpy((void*)0x200001f8,
                    "\xb4\x70\x03\x82\x00\x00\x00\xa9\xd2\x05\xdb\xb3\xdf\xf5"
                    "\x00\xff\xfe\x7f\x3b\xf7\xf4\xb8\x3d\x58\x6c\x65\x13\xe4"
                    "\xf2\x12\x00\x00\x00\x00\x00\x00\x40\x01\x00\x00\x80\x4d"
                    "\x00\x00\x60\x55\x4f\x9f\x5b\xb5\xd9\x91\x88\x35\x00\x00"
                    "\x00\x00\x00\x00\x00\x00\x00\x00",
                    64));
  NONFAILING(memcpy((void*)0x20000238,
                    "\xd3\x1e\x99\xc6\x00\x57\x5a\x02\xb8\xad\x7e\x54\x5b\x00"
                    "\x00\x00\x0b\x87\x01\x00\xf5\xff\x00\x08\xc1\x98\x81\xda"
                    "\xbb\x1d\x65\x05\x04\x40\x00\x00\x00\x6f\x00\x00\x8f\x69"
                    "\x96\x82\x43\x14\x83\x81\x2a\x4f\x96\x65\x08\x00\x00\x00"
                    "\x8f\xe1\xab\xd1\xa7\x47\x19\xa4",
                    64));
  NONFAILING(memcpy((void*)0x20000278, "\x1d\xd1\x00\x00\x00\x00\x00\x00\x00"
                                       "\x0d\x97\x00\x00\x00\x00\x00\x00\x00"
                                       "\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                                       "\x00\x00\x00\x00\x00",
                    32));
  NONFAILING(*(uint64_t*)0x20000298 = 0);
  NONFAILING(*(uint64_t*)0x200002a0 = 0);
  syscall(__NR_ioctl, r[0], 0x127f, 0x200001c0ul);
}
int main(void)
{
  syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul);
  syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul);
  install_segv_handler();
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}