// https://syzkaller.appspot.com/bug?id=5de20befde5f05afead7cffac9fb110c1d760909
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <setjmp.h>
#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <linux/loop.h>

#ifndef __NR_memfd_create
#define __NR_memfd_create 319
#endif

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 (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;                                                                        \
  })

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

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

static unsigned long fs_image_segment_check(unsigned long size,
                                            unsigned long nsegs,
                                            struct fs_image_segment* segs)
{
  if (nsegs > IMAGE_MAX_SEGMENTS)
    nsegs = IMAGE_MAX_SEGMENTS;
  for (size_t 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 int setup_loop_device(long unsigned size, long unsigned nsegs,
                             struct fs_image_segment* segs,
                             const char* loopname, int* memfd_p, int* loopfd_p)
{
  int err = 0, loopfd = -1;
  size = fs_image_segment_check(size, nsegs, segs);
  int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (ftruncate(memfd, size)) {
    err = errno;
    goto error_close_memfd;
  }
  for (size_t i = 0; i < nsegs; i++) {
    if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) {
    }
  }
  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;
    }
  }
  *memfd_p = memfd;
  *loopfd_p = loopfd;
  return 0;

error_close_loop:
  close(loopfd);
error_close_memfd:
  close(memfd);
error:
  errno = err;
  return -1;
}

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, volatile long change_dir)
{
  struct fs_image_segment* segs = (struct fs_image_segment*)segments;
  int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs;
  char* mount_opts = (char*)optsarg;
  char* target = (char*)dir;
  char* fs = (char*)fsarg;
  char* source = NULL;
  char loopname[64];
  if (need_loop_device) {
    memset(loopname, 0, sizeof(loopname));
    snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
    if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1)
      return -1;
    source = loopname;
  }
  mkdir(target, 0777);
  char opts[256];
  memset(opts, 0, sizeof(opts));
  if (strlen(mount_opts) > (sizeof(opts) - 32)) {
  }
  strncpy(opts, mount_opts, 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");
  }
  res = mount(source, target, fs, flags, opts);
  if (res == -1) {
    err = errno;
    goto error_clear_loop;
  }
  res = open(target, O_RDONLY | O_DIRECTORY);
  if (res == -1) {
    err = errno;
    goto error_clear_loop;
  }
  if (change_dir) {
    res = chdir(target);
    if (res == -1) {
      err = errno;
    }
  }

error_clear_loop:
  if (need_loop_device) {
    ioctl(loopfd, LOOP_CLR_FD, 0);
    close(loopfd);
    close(memfd);
  }
  errno = err;
  return res;
}

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();
  NONFAILING(memcpy((void*)0x20000000, "ntfs\000", 5));
  NONFAILING(memcpy((void*)0x20000100, "./file0\000", 8));
  NONFAILING(*(uint64_t*)0x20000200 = 0x20010000);
  NONFAILING(memcpy(
      (void*)0x20010000,
      "\xeb\x52\x90\x4e\x54\x46\x53\x20\x20\x20\x20\x00\x08\x01\x00\x00\x00\x00"
      "\x00\x00\x00\xf8\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
      "\x80\x00\x80\x00\xff\x03\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00"
      "\x00\x00\xff\x01\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02",
      69));
  NONFAILING(*(uint64_t*)0x20000208 = 0x45);
  NONFAILING(*(uint64_t*)0x20000210 = 0);
  NONFAILING(*(uint64_t*)0x20000218 = 0x20000340);
  NONFAILING(memcpy(
      (void*)0x20000340,
      "\x46\x49\x4c\x45\x30\x00\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00"
      "\x01\x00\x40\x00\x01\x00\xa0\x01\x00\x00\x00\x08\x00\x00\x00\x00\x00\x00"
      "\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x08\x00\x00\x00\x00\x00"
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x00\x00\x60\x00\x00\x00"
      "\x00\x00\x18\x00\x00\x00\x00\xdb\xc3\x2d\xdb\x00\x00\x48\x00\x00\x00\x18"
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x06"
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
      "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
      "\x00\x00\x00\x30\x00\x00\x00\x68\x00\x00\x00\x00\x00\x18\x00\x00\x00\x02"
      "\x00\x4a\x00\x00\x00\x18\x00\x01\x00\x05\x00\x00\x00\x00\x00\x05\x00\x80"
      "\x05\x2e\x00\xc8\x8d\xd6\x01\x80\x05\x2e\x00\xc8\x8d\xd6\x01\x80\x05\x2e"
      "\x00\xc8\x8d\xd6\x01\x80\x05\x2e\x00\xc8\x8d\xd6\x01\x00\xd8\x00\x00\x00"
      "\x00\x00\x00\x00\xd8\x00\x00\x00\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00"
      "\x00\x04\x03\x24\x00\x4d\x00\x46\x00\x54\x00\x00\x00\x00\x00\x00\x00\x80"
      "\x00\x00\x00\x48\x09\x32\xe8\x11\xb6\x40\x63\x31\x17\xf6\x13\x89\xd0\x40"
      "\xb4\x22\x02\x68\x90\x43\x73\x65\xcf\xc9\x83\x6c\x7d\x7a\x5b\x22\x84\xdf"
      "\x09\x7a\xd9\x75\x5e\x70\xa9\xfb\x29\x73\x31\xa6\x04\xcd\x64\xcc\x08\x0a"
      "\x0e\xa4\x73\xe8\xef\xbc\xfc\x5d\x03\xa8\x10\x47\xe5\x57\xa1\xe2\x6e\x86"
      "\x1b\x71\x24\xfb\xc1",
      347));
  NONFAILING(*(uint64_t*)0x20000220 = 0x15b);
  NONFAILING(*(uint64_t*)0x20000228 = 0x4000);
  NONFAILING(*(uint64_t*)0x20000230 = 0x20010500);
  NONFAILING(
      memcpy((void*)0x20010500,
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\b",
             31));
  NONFAILING(*(uint64_t*)0x20000238 = 0x1f);
  NONFAILING(*(uint64_t*)0x20000240 = 0x41e0);
  NONFAILING(*(uint64_t*)0x20000248 = 0x20010600);
  NONFAILING(
      memcpy((void*)0x20010600,
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\b",
             31));
  NONFAILING(*(uint64_t*)0x20000250 = 0x1f);
  NONFAILING(*(uint64_t*)0x20000258 = 0x43e0);
  NONFAILING(*(uint64_t*)0x20000260 = 0x20010700);
  NONFAILING(
      memcpy((void*)0x20010700,
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\b",
             31));
  NONFAILING(*(uint64_t*)0x20000268 = 0x1f);
  NONFAILING(*(uint64_t*)0x20000270 = 0x45e0);
  NONFAILING(*(uint64_t*)0x20000278 = 0x20010800);
  NONFAILING(
      memcpy((void*)0x20010800,
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000"
             "\000\000\000\000\000\000\000\000\000\000\000\000\000\000\b",
             31));
  NONFAILING(*(uint64_t*)0x20000280 = 0x1f);
  NONFAILING(*(uint64_t*)0x20000288 = 0x47e0);
  NONFAILING(*(uint8_t*)0x20000300 = 0);
  NONFAILING(syz_mount_image(0x20000000, 0x20000100, 0, 6, 0x20000200, 0,
                             0x20000300, 0));
  return 0;
}