// https://syzkaller.appspot.com/bug?id=a133db4b32d89957481e21b5080f9edfa3bf4359
// 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 <stddef.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>

#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;                                                                        \
  })

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;
}

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)
{
  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;
  }

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

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 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");
}

#define FUSE_MIN_READ_BUFFER 8192
enum fuse_opcode {
  FUSE_LOOKUP = 1,
  FUSE_FORGET = 2,
  FUSE_GETATTR = 3,
  FUSE_SETATTR = 4,
  FUSE_READLINK = 5,
  FUSE_SYMLINK = 6,
  FUSE_MKNOD = 8,
  FUSE_MKDIR = 9,
  FUSE_UNLINK = 10,
  FUSE_RMDIR = 11,
  FUSE_RENAME = 12,
  FUSE_LINK = 13,
  FUSE_OPEN = 14,
  FUSE_READ = 15,
  FUSE_WRITE = 16,
  FUSE_STATFS = 17,
  FUSE_RELEASE = 18,
  FUSE_FSYNC = 20,
  FUSE_SETXATTR = 21,
  FUSE_GETXATTR = 22,
  FUSE_LISTXATTR = 23,
  FUSE_REMOVEXATTR = 24,
  FUSE_FLUSH = 25,
  FUSE_INIT = 26,
  FUSE_OPENDIR = 27,
  FUSE_READDIR = 28,
  FUSE_RELEASEDIR = 29,
  FUSE_FSYNCDIR = 30,
  FUSE_GETLK = 31,
  FUSE_SETLK = 32,
  FUSE_SETLKW = 33,
  FUSE_ACCESS = 34,
  FUSE_CREATE = 35,
  FUSE_INTERRUPT = 36,
  FUSE_BMAP = 37,
  FUSE_DESTROY = 38,
  FUSE_IOCTL = 39,
  FUSE_POLL = 40,
  FUSE_NOTIFY_REPLY = 41,
  FUSE_BATCH_FORGET = 42,
  FUSE_FALLOCATE = 43,
  FUSE_READDIRPLUS = 44,
  FUSE_RENAME2 = 45,
  FUSE_LSEEK = 46,
  FUSE_COPY_FILE_RANGE = 47,
  FUSE_SETUPMAPPING = 48,
  FUSE_REMOVEMAPPING = 49,
  CUSE_INIT = 4096,
  CUSE_INIT_BSWAP_RESERVED = 1048576,
  FUSE_INIT_BSWAP_RESERVED = 436207616,
};
struct fuse_in_header {
  uint32_t len;
  uint32_t opcode;
  uint64_t unique;
  uint64_t nodeid;
  uint32_t uid;
  uint32_t gid;
  uint32_t pid;
  uint32_t padding;
};
struct fuse_out_header {
  uint32_t len;
  uint32_t error;
  uint64_t unique;
};
struct syz_fuse_req_out {
  struct fuse_out_header* init;
  struct fuse_out_header* lseek;
  struct fuse_out_header* bmap;
  struct fuse_out_header* poll;
  struct fuse_out_header* getxattr;
  struct fuse_out_header* lk;
  struct fuse_out_header* statfs;
  struct fuse_out_header* write;
  struct fuse_out_header* read;
  struct fuse_out_header* open;
  struct fuse_out_header* attr;
  struct fuse_out_header* entry;
  struct fuse_out_header* dirent;
  struct fuse_out_header* direntplus;
  struct fuse_out_header* create_open;
  struct fuse_out_header* ioctl;
};
static int fuse_send_response(int fd, const struct fuse_in_header* in_hdr,
                              struct fuse_out_header* out_hdr)
{
  if (!out_hdr) {
    return -1;
  }
  out_hdr->unique = in_hdr->unique;
  if (write(fd, out_hdr, out_hdr->len) == -1) {
    return -1;
  }
  return 0;
}
static volatile long syz_fuse_handle_req(volatile long a0, volatile long a1,
                                         volatile long a2, volatile long a3)
{
  struct syz_fuse_req_out* req_out = (struct syz_fuse_req_out*)a3;
  struct fuse_out_header* out_hdr = NULL;
  char* buf = (char*)a1;
  int buf_len = (int)a2;
  int fd = (int)a0;
  if (!req_out) {
    return -1;
  }
  if (buf_len < FUSE_MIN_READ_BUFFER) {
    return -1;
  }
  int ret = read(fd, buf, buf_len);
  if (ret == -1) {
    return -1;
  }
  if ((size_t)ret < sizeof(struct fuse_in_header)) {
    return -1;
  }
  const struct fuse_in_header* in_hdr = (const struct fuse_in_header*)buf;
  if (in_hdr->len > (uint32_t)ret) {
    return -1;
  }
  switch (in_hdr->opcode) {
  case FUSE_GETATTR:
  case FUSE_SETATTR:
    out_hdr = req_out->attr;
    break;
  case FUSE_LOOKUP:
  case FUSE_SYMLINK:
  case FUSE_LINK:
  case FUSE_MKNOD:
  case FUSE_MKDIR:
    out_hdr = req_out->entry;
    break;
  case FUSE_OPEN:
  case FUSE_OPENDIR:
    out_hdr = req_out->open;
    break;
  case FUSE_STATFS:
    out_hdr = req_out->statfs;
    break;
  case FUSE_RMDIR:
  case FUSE_RENAME:
  case FUSE_RENAME2:
  case FUSE_FALLOCATE:
  case FUSE_SETXATTR:
  case FUSE_REMOVEXATTR:
  case FUSE_FSYNCDIR:
  case FUSE_FSYNC:
  case FUSE_SETLKW:
  case FUSE_SETLK:
  case FUSE_ACCESS:
  case FUSE_FLUSH:
  case FUSE_RELEASE:
  case FUSE_RELEASEDIR:
  case FUSE_UNLINK:
  case FUSE_DESTROY:
    out_hdr = req_out->init;
    if (!out_hdr) {
      return -1;
    }
    out_hdr->len = sizeof(struct fuse_out_header);
    break;
  case FUSE_READ:
    out_hdr = req_out->read;
    break;
  case FUSE_READDIR:
    out_hdr = req_out->dirent;
    break;
  case FUSE_READDIRPLUS:
    out_hdr = req_out->direntplus;
    break;
  case FUSE_INIT:
    out_hdr = req_out->init;
    break;
  case FUSE_LSEEK:
    out_hdr = req_out->lseek;
    break;
  case FUSE_GETLK:
    out_hdr = req_out->lk;
    break;
  case FUSE_BMAP:
    out_hdr = req_out->bmap;
    break;
  case FUSE_POLL:
    out_hdr = req_out->poll;
    break;
  case FUSE_GETXATTR:
  case FUSE_LISTXATTR:
    out_hdr = req_out->getxattr;
    break;
  case FUSE_WRITE:
  case FUSE_COPY_FILE_RANGE:
    out_hdr = req_out->write;
    break;
  case FUSE_FORGET:
  case FUSE_BATCH_FORGET:
    return 0;
  case FUSE_CREATE:
    out_hdr = req_out->create_open;
    break;
  case FUSE_IOCTL:
    out_hdr = req_out->ioctl;
    break;
  default:
    return -1;
  }
  return fuse_send_response(fd, in_hdr, out_hdr);
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  int iter = 0;
  for (;; 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 < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
  }
}

uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  NONFAILING(memcpy((void*)0x20000440, "./file0\000", 8));
  NONFAILING(syz_mount_image(0, 0x20000440, 0, 0, 0, 0, 0));
  res = syscall(__NR_pipe2, 0x200000c0ul, 0ul);
  if (res != -1) {
    NONFAILING(r[0] = *(uint32_t*)0x200000c0);
    NONFAILING(r[1] = *(uint32_t*)0x200000c4);
  }
  NONFAILING(*(uint64_t*)0x200013c0 = 0);
  NONFAILING(*(uint64_t*)0x200013c8 = 0);
  NONFAILING(*(uint64_t*)0x200013d0 = 0);
  NONFAILING(*(uint64_t*)0x200013d8 = 0);
  NONFAILING(*(uint64_t*)0x200013e0 = 0);
  NONFAILING(*(uint64_t*)0x200013e8 = 0);
  NONFAILING(*(uint64_t*)0x200013f0 = 0);
  NONFAILING(*(uint64_t*)0x200013f8 = 0);
  NONFAILING(*(uint64_t*)0x20001400 = 0);
  NONFAILING(*(uint64_t*)0x20001408 = 0);
  NONFAILING(*(uint64_t*)0x20001410 = 0x200006c0);
  NONFAILING(*(uint32_t*)0x200006c0 = 0x78);
  NONFAILING(*(uint32_t*)0x200006c4 = 0xd6b90b62);
  NONFAILING(*(uint64_t*)0x200006c8 = 5);
  NONFAILING(*(uint64_t*)0x200006d0 = 0x7f);
  NONFAILING(*(uint32_t*)0x200006d8 = 6);
  NONFAILING(*(uint32_t*)0x200006dc = 0);
  NONFAILING(*(uint64_t*)0x200006e0 = 1);
  NONFAILING(*(uint64_t*)0x200006e8 = 4);
  NONFAILING(*(uint64_t*)0x200006f0 = 7);
  NONFAILING(*(uint64_t*)0x200006f8 = 0xffffffff);
  NONFAILING(*(uint64_t*)0x20000700 = 0x3ff);
  NONFAILING(*(uint64_t*)0x20000708 = 0x7fffffff);
  NONFAILING(*(uint32_t*)0x20000710 = 0xfffffff8);
  NONFAILING(*(uint32_t*)0x20000714 = 0);
  NONFAILING(*(uint32_t*)0x20000718 = 9);
  NONFAILING(*(uint32_t*)0x2000071c = 0x4000);
  NONFAILING(*(uint32_t*)0x20000720 = 0);
  NONFAILING(*(uint32_t*)0x20000724 = 0);
  NONFAILING(*(uint32_t*)0x20000728 = 0);
  NONFAILING(*(uint32_t*)0x2000072c = 0x100);
  NONFAILING(*(uint32_t*)0x20000730 = 3);
  NONFAILING(*(uint32_t*)0x20000734 = 0);
  NONFAILING(*(uint64_t*)0x20001418 = 0);
  NONFAILING(*(uint64_t*)0x20001420 = 0);
  NONFAILING(*(uint64_t*)0x20001428 = 0);
  NONFAILING(*(uint64_t*)0x20001430 = 0);
  NONFAILING(*(uint64_t*)0x20001438 = 0);
  NONFAILING(syz_fuse_handle_req(-1, 0, 0, 0x200013c0));
  NONFAILING(memcpy((void*)0x20000300,
                    "\x15\x00\x00\x00\x65\xff\xff\x01\x80\x00\x00\x08\x00\x39"
                    "\x50\x32\x30\x30\x30",
                    19));
  syscall(__NR_write, r[1], 0x20000300ul, 0x15ul);
  res = syscall(__NR_dup, r[1]);
  if (res != -1)
    r[2] = res;
  NONFAILING(*(uint32_t*)0x20000000 = 0x18);
  NONFAILING(*(uint32_t*)0x20000004 = 0);
  NONFAILING(*(uint64_t*)0x20000008 = 0);
  NONFAILING(*(uint64_t*)0x20000010 = 0);
  syscall(__NR_write, r[2], 0x20000000ul, 0x18ul);
  syscall(__NR_write, r[2], 0x20000700ul, 0x138ul);
  NONFAILING(memcpy((void*)0x20000040, "./file0\000", 8));
  NONFAILING(memcpy((void*)0x20000080, "9p\000", 3));
  NONFAILING(memcpy((void*)0x20000100, "trans=fd,", 9));
  NONFAILING(memcpy((void*)0x20000109, "rfdno", 5));
  NONFAILING(*(uint8_t*)0x2000010e = 0x3d);
  NONFAILING(sprintf((char*)0x2000010f, "0x%016llx", (long long)r[0]));
  NONFAILING(*(uint8_t*)0x20000121 = 0x2c);
  NONFAILING(memcpy((void*)0x20000122, "wfdno", 5));
  NONFAILING(*(uint8_t*)0x20000127 = 0x3d);
  NONFAILING(sprintf((char*)0x20000128, "0x%016llx", (long long)r[1]));
  NONFAILING(*(uint8_t*)0x2000013a = 0x2c);
  NONFAILING(*(uint8_t*)0x2000013b = 0);
  syscall(__NR_mount, 0ul, 0x20000040ul, 0x20000080ul, 0ul, 0x20000100ul);
  syscall(__NR_sync);
}
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();
  loop();
  return 0;
}