// https://syzkaller.appspot.com/bug?id=b6186603058cc4dbf6ab5cc4794ac03d9a5f9d3e
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.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/mman.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <linux/genetlink.h>
#include <linux/if_addr.h>
#include <linux/if_link.h>
#include <linux/in6.h>
#include <linux/loop.h>
#include <linux/neighbour.h>
#include <linux/net.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/veth.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 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 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 nlmsg {
  char* pos;
  int nesting;
  struct nlattr* nested[8];
  char buf[4096];
};

static void netlink_init(struct nlmsg* nlmsg, int typ, int flags,
                         const void* data, int size)
{
  memset(nlmsg, 0, sizeof(*nlmsg));
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_type = typ;
  hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags;
  memcpy(hdr + 1, data, size);
  nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size);
}

static void netlink_attr(struct nlmsg* nlmsg, int typ, const void* data,
                         int size)
{
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_len = sizeof(*attr) + size;
  attr->nla_type = typ;
  if (size > 0)
    memcpy(attr + 1, data, size);
  nlmsg->pos += NLMSG_ALIGN(attr->nla_len);
}

static void netlink_nest(struct nlmsg* nlmsg, int typ)
{
  struct nlattr* attr = (struct nlattr*)nlmsg->pos;
  attr->nla_type = typ;
  nlmsg->pos += sizeof(*attr);
  nlmsg->nested[nlmsg->nesting++] = attr;
}

static void netlink_done(struct nlmsg* nlmsg)
{
  struct nlattr* attr = nlmsg->nested[--nlmsg->nesting];
  attr->nla_len = nlmsg->pos - (char*)attr;
}

static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type,
                            int* reply_len, bool dofail)
{
  if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting)
    exit(1);
  struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf;
  hdr->nlmsg_len = nlmsg->pos - nlmsg->buf;
  struct sockaddr_nl addr;
  memset(&addr, 0, sizeof(addr));
  addr.nl_family = AF_NETLINK;
  ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0,
                     (struct sockaddr*)&addr, sizeof(addr));
  if (n != (ssize_t)hdr->nlmsg_len) {
    if (dofail)
      exit(1);
    return -1;
  }
  n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  if (reply_len)
    *reply_len = 0;
  if (n < 0) {
    if (dofail)
      exit(1);
    return -1;
  }
  if (n < (ssize_t)sizeof(struct nlmsghdr)) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type == NLMSG_DONE)
    return 0;
  if (reply_len && hdr->nlmsg_type == reply_type) {
    *reply_len = n;
    return 0;
  }
  if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  if (hdr->nlmsg_type != NLMSG_ERROR) {
    errno = EINVAL;
    if (dofail)
      exit(1);
    return -1;
  }
  errno = -((struct nlmsgerr*)(hdr + 1))->error;
  return -errno;
}

static int netlink_send(struct nlmsg* nlmsg, int sock)
{
  return netlink_send_ext(nlmsg, sock, 0, NULL, true);
}

static int netlink_query_family_id(struct nlmsg* nlmsg, int sock,
                                   const char* family_name, bool dofail)
{
  struct genlmsghdr genlhdr;
  memset(&genlhdr, 0, sizeof(genlhdr));
  genlhdr.cmd = CTRL_CMD_GETFAMILY;
  netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr));
  netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name,
               strnlen(family_name, GENL_NAMSIZ - 1) + 1);
  int n = 0;
  int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail);
  if (err < 0) {
    return -1;
  }
  uint16_t id = 0;
  struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN +
                                         NLMSG_ALIGN(sizeof(genlhdr)));
  for (; (char*)attr < nlmsg->buf + n;
       attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) {
    if (attr->nla_type == CTRL_ATTR_FAMILY_ID) {
      id = *(uint16_t*)(attr + 1);
      break;
    }
  }
  if (!id) {
    errno = EINVAL;
    return -1;
  }
  recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0);
  return id;
}

static void netlink_add_device_impl(struct nlmsg* nlmsg, const char* type,
                                    const char* name, bool up)
{
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  netlink_init(nlmsg, RTM_NEWLINK, NLM_F_EXCL | NLM_F_CREATE, &hdr,
               sizeof(hdr));
  if (name)
    netlink_attr(nlmsg, IFLA_IFNAME, name, strlen(name));
  netlink_nest(nlmsg, IFLA_LINKINFO);
  netlink_attr(nlmsg, IFLA_INFO_KIND, type, strlen(type));
}

static void netlink_device_change(struct nlmsg* nlmsg, int sock,
                                  const char* name, bool up, const char* master,
                                  const void* mac, int macsize,
                                  const char* new_name)
{
  struct ifinfomsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  if (up)
    hdr.ifi_flags = hdr.ifi_change = IFF_UP;
  hdr.ifi_index = if_nametoindex(name);
  netlink_init(nlmsg, RTM_NEWLINK, 0, &hdr, sizeof(hdr));
  if (new_name)
    netlink_attr(nlmsg, IFLA_IFNAME, new_name, strlen(new_name));
  if (master) {
    int ifindex = if_nametoindex(master);
    netlink_attr(nlmsg, IFLA_MASTER, &ifindex, sizeof(ifindex));
  }
  if (macsize)
    netlink_attr(nlmsg, IFLA_ADDRESS, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static struct nlmsg nlmsg;

//% This code is derived from puff.{c,h}, found in the zlib development. The
//% original files come with the following copyright notice:

//% Copyright (C) 2002-2013 Mark Adler, all rights reserved
//% version 2.3, 21 Jan 2013
//% This software is provided 'as-is', without any express or implied
//% warranty.  In no event will the author be held liable for any damages
//% arising from the use of this software.
//% Permission is granted to anyone to use this software for any purpose,
//% including commercial applications, and to alter it and redistribute it
//% freely, subject to the following restrictions:
//% 1. The origin of this software must not be misrepresented; you must not
//%    claim that you wrote the original software. If you use this software
//%    in a product, an acknowledgment in the product documentation would be
//%    appreciated but is not required.
//% 2. Altered source versions must be plainly marked as such, and must not be
//%    misrepresented as being the original software.
//% 3. This notice may not be removed or altered from any source distribution.
//% Mark Adler    madler@alumni.caltech.edu

//% BEGIN CODE DERIVED FROM puff.{c,h}

#define MAXBITS 15
#define MAXLCODES 286
#define MAXDCODES 30
#define MAXCODES (MAXLCODES + MAXDCODES)
#define FIXLCODES 288

struct puff_state {
  unsigned char* out;
  unsigned long outlen;
  unsigned long outcnt;
  const unsigned char* in;
  unsigned long inlen;
  unsigned long incnt;
  int bitbuf;
  int bitcnt;
  jmp_buf env;
};
static int puff_bits(struct puff_state* s, int need)
{
  long val = s->bitbuf;
  while (s->bitcnt < need) {
    if (s->incnt == s->inlen)
      longjmp(s->env, 1);
    val |= (long)(s->in[s->incnt++]) << s->bitcnt;
    s->bitcnt += 8;
  }
  s->bitbuf = (int)(val >> need);
  s->bitcnt -= need;
  return (int)(val & ((1L << need) - 1));
}
static int puff_stored(struct puff_state* s)
{
  s->bitbuf = 0;
  s->bitcnt = 0;
  if (s->incnt + 4 > s->inlen)
    return 2;
  unsigned len = s->in[s->incnt++];
  len |= s->in[s->incnt++] << 8;
  if (s->in[s->incnt++] != (~len & 0xff) ||
      s->in[s->incnt++] != ((~len >> 8) & 0xff))
    return -2;
  if (s->incnt + len > s->inlen)
    return 2;
  if (s->outcnt + len > s->outlen)
    return 1;
  for (; len--; s->outcnt++, s->incnt++) {
    if (s->in[s->incnt])
      s->out[s->outcnt] = s->in[s->incnt];
  }
  return 0;
}
struct puff_huffman {
  short* count;
  short* symbol;
};
static int puff_decode(struct puff_state* s, const struct puff_huffman* h)
{
  int first = 0;
  int index = 0;
  int bitbuf = s->bitbuf;
  int left = s->bitcnt;
  int code = first = index = 0;
  int len = 1;
  short* next = h->count + 1;
  while (1) {
    while (left--) {
      code |= bitbuf & 1;
      bitbuf >>= 1;
      int count = *next++;
      if (code - count < first) {
        s->bitbuf = bitbuf;
        s->bitcnt = (s->bitcnt - len) & 7;
        return h->symbol[index + (code - first)];
      }
      index += count;
      first += count;
      first <<= 1;
      code <<= 1;
      len++;
    }
    left = (MAXBITS + 1) - len;
    if (left == 0)
      break;
    if (s->incnt == s->inlen)
      longjmp(s->env, 1);
    bitbuf = s->in[s->incnt++];
    if (left > 8)
      left = 8;
  }
  return -10;
}
static int puff_construct(struct puff_huffman* h, const short* length, int n)
{
  int len;
  for (len = 0; len <= MAXBITS; len++)
    h->count[len] = 0;
  int symbol;
  for (symbol = 0; symbol < n; symbol++)
    (h->count[length[symbol]])++;
  if (h->count[0] == n)
    return 0;
  int left = 1;
  for (len = 1; len <= MAXBITS; len++) {
    left <<= 1;
    left -= h->count[len];
    if (left < 0)
      return left;
  }
  short offs[MAXBITS + 1];
  offs[1] = 0;
  for (len = 1; len < MAXBITS; len++)
    offs[len + 1] = offs[len] + h->count[len];
  for (symbol = 0; symbol < n; symbol++)
    if (length[symbol] != 0)
      h->symbol[offs[length[symbol]]++] = symbol;
  return left;
}
static int puff_codes(struct puff_state* s, const struct puff_huffman* lencode,
                      const struct puff_huffman* distcode)
{
  static const short lens[29] = {3,  4,  5,  6,   7,   8,   9,   10,  11, 13,
                                 15, 17, 19, 23,  27,  31,  35,  43,  51, 59,
                                 67, 83, 99, 115, 131, 163, 195, 227, 258};
  static const short lext[29] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
                                 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0};
  static const short dists[30] = {
      1,    2,    3,    4,    5,    7,    9,    13,    17,    25,
      33,   49,   65,   97,   129,  193,  257,  385,   513,   769,
      1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
  static const short dext[30] = {0, 0, 0,  0,  1,  1,  2,  2,  3,  3,
                                 4, 4, 5,  5,  6,  6,  7,  7,  8,  8,
                                 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
  int symbol;
  do {
    symbol = puff_decode(s, lencode);
    if (symbol < 0)
      return symbol;
    if (symbol < 256) {
      if (s->outcnt == s->outlen)
        return 1;
      if (symbol)
        s->out[s->outcnt] = symbol;
      s->outcnt++;
    } else if (symbol > 256) {
      symbol -= 257;
      if (symbol >= 29)
        return -10;
      int len = lens[symbol] + puff_bits(s, lext[symbol]);
      symbol = puff_decode(s, distcode);
      if (symbol < 0)
        return symbol;
      unsigned dist = dists[symbol] + puff_bits(s, dext[symbol]);
      if (dist > s->outcnt)
        return -11;
      if (s->outcnt + len > s->outlen)
        return 1;
      while (len--) {
        if (dist <= s->outcnt && s->out[s->outcnt - dist])
          s->out[s->outcnt] = s->out[s->outcnt - dist];
        s->outcnt++;
      }
    }
  } while (symbol != 256);
  return 0;
}
static int puff_fixed(struct puff_state* s)
{
  static int virgin = 1;
  static short lencnt[MAXBITS + 1], lensym[FIXLCODES];
  static short distcnt[MAXBITS + 1], distsym[MAXDCODES];
  static struct puff_huffman lencode, distcode;
  if (virgin) {
    lencode.count = lencnt;
    lencode.symbol = lensym;
    distcode.count = distcnt;
    distcode.symbol = distsym;
    short lengths[FIXLCODES];
    int symbol;
    for (symbol = 0; symbol < 144; symbol++)
      lengths[symbol] = 8;
    for (; symbol < 256; symbol++)
      lengths[symbol] = 9;
    for (; symbol < 280; symbol++)
      lengths[symbol] = 7;
    for (; symbol < FIXLCODES; symbol++)
      lengths[symbol] = 8;
    puff_construct(&lencode, lengths, FIXLCODES);
    for (symbol = 0; symbol < MAXDCODES; symbol++)
      lengths[symbol] = 5;
    puff_construct(&distcode, lengths, MAXDCODES);
    virgin = 0;
  }
  return puff_codes(s, &lencode, &distcode);
}
static int puff_dynamic(struct puff_state* s)
{
  static const short order[19] = {16, 17, 18, 0, 8,  7, 9,  6, 10, 5,
                                  11, 4,  12, 3, 13, 2, 14, 1, 15};
  int nlen = puff_bits(s, 5) + 257;
  int ndist = puff_bits(s, 5) + 1;
  int ncode = puff_bits(s, 4) + 4;
  if (nlen > MAXLCODES || ndist > MAXDCODES)
    return -3;
  short lengths[MAXCODES];
  int index;
  for (index = 0; index < ncode; index++)
    lengths[order[index]] = puff_bits(s, 3);
  for (; index < 19; index++)
    lengths[order[index]] = 0;
  short lencnt[MAXBITS + 1], lensym[MAXLCODES];
  struct puff_huffman lencode = {lencnt, lensym};
  int err = puff_construct(&lencode, lengths, 19);
  if (err != 0)
    return -4;
  index = 0;
  while (index < nlen + ndist) {
    int symbol;
    int len;
    symbol = puff_decode(s, &lencode);
    if (symbol < 0)
      return symbol;
    if (symbol < 16)
      lengths[index++] = symbol;
    else {
      len = 0;
      if (symbol == 16) {
        if (index == 0)
          return -5;
        len = lengths[index - 1];
        symbol = 3 + puff_bits(s, 2);
      } else if (symbol == 17)
        symbol = 3 + puff_bits(s, 3);
      else
        symbol = 11 + puff_bits(s, 7);
      if (index + symbol > nlen + ndist)
        return -6;
      while (symbol--)
        lengths[index++] = len;
    }
  }
  if (lengths[256] == 0)
    return -9;
  err = puff_construct(&lencode, lengths, nlen);
  if (err && (err < 0 || nlen != lencode.count[0] + lencode.count[1]))
    return -7;
  short distcnt[MAXBITS + 1], distsym[MAXDCODES];
  struct puff_huffman distcode = {distcnt, distsym};
  err = puff_construct(&distcode, lengths + nlen, ndist);
  if (err && (err < 0 || ndist != distcode.count[0] + distcode.count[1]))
    return -8;
  return puff_codes(s, &lencode, &distcode);
}
static int puff(unsigned char* dest, unsigned long* destlen,
                const unsigned char* source, unsigned long sourcelen)
{
  struct puff_state s = {
      .out = dest,
      .outlen = *destlen,
      .outcnt = 0,
      .in = source,
      .inlen = sourcelen,
      .incnt = 0,
      .bitbuf = 0,
      .bitcnt = 0,
  };
  int err;
  if (setjmp(s.env) != 0)
    err = 2;
  else {
    int last;
    do {
      last = puff_bits(&s, 1);
      int type = puff_bits(&s, 2);
      err = type == 0 ? puff_stored(&s)
                      : (type == 1 ? puff_fixed(&s)
                                   : (type == 2 ? puff_dynamic(&s) : -1));
      if (err != 0)
        break;
    } while (!last);
  }
  *destlen = s.outcnt;
  return err;
}

//% END CODE DERIVED FROM puff.{c,h}

#define ZLIB_HEADER_WIDTH 2

static int puff_zlib_to_file(const unsigned char* source,
                             unsigned long sourcelen, int dest_fd)
{
  if (sourcelen < ZLIB_HEADER_WIDTH)
    return 0;
  source += ZLIB_HEADER_WIDTH;
  sourcelen -= ZLIB_HEADER_WIDTH;
  const unsigned long max_destlen = 132 << 20;
  void* ret = mmap(0, max_destlen, PROT_WRITE | PROT_READ,
                   MAP_PRIVATE | MAP_ANON, -1, 0);
  if (ret == MAP_FAILED)
    return -1;
  unsigned char* dest = (unsigned char*)ret;
  unsigned long destlen = max_destlen;
  int err = puff(dest, &destlen, source, sourcelen);
  if (err) {
    munmap(dest, max_destlen);
    errno = -err;
    return -1;
  }
  if (write(dest_fd, dest, destlen) != (ssize_t)destlen) {
    munmap(dest, max_destlen);
    return -1;
  }
  return munmap(dest, destlen);
}

static int setup_loop_device(unsigned char* data, unsigned long size,
                             const char* loopname, int* loopfd_p)
{
  int err = 0, loopfd = -1;
  int memfd = syscall(__NR_memfd_create, "syzkaller", 0);
  if (memfd == -1) {
    err = errno;
    goto error;
  }
  if (puff_zlib_to_file(data, size, memfd)) {
    err = errno;
    goto error_close_memfd;
  }
  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;
    }
  }
  close(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 long flags, volatile long optsarg,
                            volatile long change_dir,
                            volatile unsigned long size, volatile long image)
{
  unsigned char* data = (unsigned char*)image;
  int res = -1, err = 0, loopfd = -1, need_loop_device = !!size;
  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(data, size, loopname, &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) {
    bool has_remount_ro = false;
    char* remount_ro_start = strstr(opts, "errors=remount-ro");
    if (remount_ro_start != NULL) {
      char after = *(remount_ro_start + strlen("errors=remount-ro"));
      char before = remount_ro_start == opts ? '\0' : *(remount_ro_start - 1);
      has_remount_ro = ((before == '\0' || before == ',') &&
                        (after == '\0' || after == ','));
    }
    if (strstr(opts, "errors=panic") || !has_remount_ro)
      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);
  }
  errno = err;
  return res;
}

static int inject_fault(int nth)
{
  int fd;
  fd = open("/proc/thread-self/fail-nth", O_RDWR);
  if (fd == -1)
    exit(1);
  char buf[16];
  sprintf(buf, "%d", nth);
  if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
    exit(1);
  return fd;
}

static void setup_fault()
{
  static struct {
    const char* file;
    const char* val;
    bool fatal;
  } files[] = {
      {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true},
      {"/sys/kernel/debug/fail_futex/ignore-private", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false},
  };
  unsigned i;
  for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].file, files[i].val)) {
      if (files[i].fatal)
        exit(1);
    }
  }
}

static void setup_sysctl()
{
  char mypid[32];
  snprintf(mypid, sizeof(mypid), "%d", getpid());
  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", mypid},
  };
  for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].name, files[i].data))
      printf("write to %s failed: %s\n", files[i].name, strerror(errno));
  }
}

#define NL802154_CMD_SET_SHORT_ADDR 11
#define NL802154_ATTR_IFINDEX 3
#define NL802154_ATTR_SHORT_ADDR 10

static void setup_802154()
{
  int sock_route = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if (sock_route == -1)
    exit(1);
  int sock_generic = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
  if (sock_generic < 0)
    exit(1);
  int nl802154_family_id =
      netlink_query_family_id(&nlmsg, sock_generic, "nl802154", true);
  for (int i = 0; i < 2; i++) {
    char devname[] = "wpan0";
    devname[strlen(devname) - 1] += i;
    uint64_t hwaddr = 0xaaaaaaaaaaaa0002 + (i << 8);
    uint16_t shortaddr = 0xaaa0 + i;
    int ifindex = if_nametoindex(devname);
    struct genlmsghdr genlhdr;
    memset(&genlhdr, 0, sizeof(genlhdr));
    genlhdr.cmd = NL802154_CMD_SET_SHORT_ADDR;
    netlink_init(&nlmsg, nl802154_family_id, 0, &genlhdr, sizeof(genlhdr));
    netlink_attr(&nlmsg, NL802154_ATTR_IFINDEX, &ifindex, sizeof(ifindex));
    netlink_attr(&nlmsg, NL802154_ATTR_SHORT_ADDR, &shortaddr,
                 sizeof(shortaddr));
    int err = netlink_send(&nlmsg, sock_generic);
    if (err < 0) {
    }
    netlink_device_change(&nlmsg, sock_route, devname, true, 0, &hwaddr,
                          sizeof(hwaddr), 0);
    if (i == 0) {
      netlink_add_device_impl(&nlmsg, "lowpan", "lowpan0", false);
      netlink_done(&nlmsg);
      netlink_attr(&nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex));
      int err = netlink_send(&nlmsg, sock_route);
      if (err < 0) {
      }
    }
  }
  close(sock_route);
  close(sock_generic);
}

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);
  setup_sysctl();
  setup_fault();
  setup_802154();
  install_segv_handler();
  use_temporary_dir();
  NONFAILING(memcpy((void*)0x200004c0, "udf\000", 4));
  NONFAILING(memcpy((void*)0x20000500, "./file0\000", 8));
  NONFAILING(*(uint8_t*)0x20000540 = 0);
  NONFAILING(memcpy(
      (void*)0x20000580,
      "\x78\x9c\xec\xdb\x4d\x6c\x54\x55\x18\xc6\xf1\xe7\x9d\x3b\x33\x4c\x07\x94"
      "\xf2\x61\x41\x43\x70\x8c\x0b\x0a\x6a\x69\x3b\x20\x24\x35\x31\x85\x5a\x95"
      "\xf0\xa1\x40\x4d\x34\x46\x52\xe9\x14\x2b\xfd\x4a\xa7\x18\x4a\x88\xb0\x70"
      "\xa3\xae\x59\xba\x32\xba\x31\xd1\xe8\x4a\x5d\xb8\x23\xd1\xc4\x18\x63\x8c"
      "\xc1\x05\x71\xa3\x6e\xdc\xcc\x4a\x96\x98\x73\xe7\x7e\xcd\x50\xe8\x54\xda"
      "\x19\x4a\xff\x3f\x02\xe7\xde\x3b\xef\x0c\xe7\xbc\xef\xdc\x39\xe7\x4c\x5a"
      "\x01\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\x00\x00\x00\x00\x00\x00\x00\x00\xe9\xc0\x73\xfd\xdd\x3d"
      "\xd6\xea\x5e\x00\x00\x80\x66\x3a\x7a\xe2\x78\x77\x91\xf9\x1f\x00\x80\x55"
      "\xe5\x24\xfb\x7f\x00\x00\x80\xd5\xc4\xe4\xe9\x4b\x99\x76\x3c\x5f\xb1\x23"
      "\xfe\x79\x55\xee\xf0\xd8\xe4\xb9\xf3\x43\x03\x83\xf3\x3f\xad\xcd\x64\x4a"
      "\xc9\xf3\xe3\xdd\xdf\x5c\x4f\x6f\x71\xcf\xde\xa7\xf7\xed\x0f\xdb\x3b\x3f"
      "\x7f\xa9\x3d\xac\x63\x27\x4e\xf6\x17\x0e\x4e\x4d\x4c\xcf\x94\xca\xe5\xd2"
      "\x48\x61\x68\x72\xec\xf4\xd4\x48\xa9\xe1\x57\xb8\xdb\xe7\xd7\xdb\xe5\x27"
      "\xa0\x30\x71\xf6\xdc\xc8\xe8\x68\xb9\xd0\xdb\x55\xac\x79\xf8\x7c\xfb\xdf"
      "\x6b\xd6\x76\xb4\xf7\xed\x3b\xd4\x75\x28\x8c\x1d\x1a\x18\x1c\x3c\x91\x88"
      "\x49\x67\xfe\xf7\xff\x7e\x8b\xdb\xad\xf0\xb3\xf2\xb4\x53\xa6\xb7\xbf\xfe"
      "\xdc\x8e\x4a\x4a\xe9\xee\x73\xb1\xc0\x7b\x67\xb9\xb5\xf9\x83\xd8\xe5\x0f"
      "\x62\x68\x60\xd0\x1f\xc8\xf8\xd8\xf0\xe4\xac\x7b\xd0\x52\x41\x54\xaa\x36"
      "\x27\xd9\x30\x47\x4d\xa8\xc5\x5d\x49\x49\xae\x5f\x96\x5d\x9a\x3d\x5b\x46"
      "\x9e\xbe\x95\xe9\xc0\xee\x8a\x1d\x93\xe4\x85\x79\x78\xc2\xff\x62\xb8\xa1"
      "\xfe\xb4\x42\xda\x6d\x5d\x25\x75\x6a\x05\xd4\xec\x1e\xb6\x46\x9e\x4e\xc9"
      "\x74\x75\x77\xbb\x5e\x0a\xf2\xea\xd7\x3f\x2b\x5d\x6c\x75\xe7\xb0\xec\xd2"
      "\xc1\xfd\x3f\x65\x15\x7b\xd9\xff\x3c\x70\xf7\x93\xfb\xd8\x3c\xfc\x4a\xe1"
      "\xc5\xc9\xd1\xa9\x44\xac\xa5\x82\x3b\x6a\xa5\xcf\x0f\xcd\x74\x8f\x7f\x36"
      "\xe5\xe4\xe9\x98\x7f\xc7\x57\xec\x78\xab\x3b\x83\xa6\x6b\x93\xa7\x83\x32"
      "\x7d\xf7\xc5\x3b\xfe\xba\x42\xfe\xba\x74\x7d\xdf\xfe\xc7\x06\x4e\x25\x57"
      "\x18\x5b\x16\x78\x1d\x17\xdb\x15\xdc\x5c\x8d\xcc\xc9\x99\x60\xe9\x60\x29"
      "\xf7\x67\xe9\xc7\x85\xc6\xe4\xcc\xd3\x5f\x32\xdd\xf8\x3d\xe7\x9f\x77\x86"
      "\x73\x80\x74\xf9\x66\x6b\xbb\x86\x66\x30\x4f\x47\x65\xfa\xf1\xc3\x8a\x59"
      "\xdd\xbe\xd4\x4b\xec\xef\x23\x2b\x7d\xee\x5f\xde\xfe\xb7\xe5\x0e\x4e\x4d"
      "\xcf\xcd\x8c\x9d\x79\x6b\x76\xde\xc7\xf3\xb9\xfe\x37\xcb\xb3\x33\xc3\xa7"
      "\xe7\x7f\xb8\xba\x77\xf5\x92\x57\x16\xda\xc7\xd6\x4b\x2d\x6e\x4b\x96\x37"
      "\x4f\xcf\xca\xf4\xd3\x74\x25\x7a\x5e\xb0\x07\x78\xa0\x7a\x16\xf7\xe6\x93"
      "\x8b\xf1\x7b\xa1\xb3\xae\x0d\x25\xdf\x3f\x8d\x1c\x37\xbc\x8b\x5d\xc4\x3a"
      "\xca\xf5\xc9\xcc\xd3\x9f\x32\x8d\xbe\xb1\xb5\x3a\xcf\x28\xbf\xe8\xdc\xac"
      "\x06\xae\xfe\xbf\xca\x74\x69\xe6\x67\x0b\x2b\x1d\xd4\x3f\x5d\x3d\x4b\xd4"
      "\xff\x99\x38\x7f\x39\xab\x6d\x23\x7e\x6d\x1f\xac\x7e\xaf\x15\xae\x25\x0a"
      "\xdb\x1f\xbd\xdd\xf5\xe5\xa8\xbf\xeb\x93\xab\xff\xab\x32\x1d\xf8\x77\x6b"
      "\xf0\x9d\x46\xb5\xfe\x5e\x5d\xac\x8b\xeb\x90\xe9\xf5\x2b\xdb\x82\xb8\x54"
      "\xd6\xc5\xa5\xc3\xe1\x54\x5f\x71\x74\x6c\xbc\xd4\xed\x62\x6f\xca\xb4\xf1"
      "\xfb\x30\x56\x7e\x6c\x3e\x88\xdd\x14\xc7\xf6\xb8\xd8\xb2\x4c\xef\x5f\xad"
      "\x8d\x5d\x1b\xc4\x6e\x8e\x63\x7b\x5d\xec\x35\x99\xae\xff\x36\x7f\xec\x43"
      "\x71\x6c\xd1\xc5\xce\xc9\x54\xbe\x5e\x08\x63\xf3\x2e\x76\x7b\x10\xdb\x11"
      "\xc7\x76\x9d\x9e\x1a\x1f\x59\x28\xad\xae\xfe\x1f\xcb\xd4\x9f\x7d\xc1\xc2"
      "\x31\xdf\xb6\xfe\x89\xfb\xff\x72\x5d\x1b\xb9\xa5\xe6\x77\x3e\x5e\xaa\xfa"
      "\xb7\x27\xae\x5d\x0e\xea\xfa\x5a\x50\xff\xf4\x02\xf5\xff\x40\xa6\xb9\x7f"
      "\xb6\x85\xe3\xf6\x73\x1f\xbe\xad\x36\xf8\xff\xc6\xf5\x9f\x90\xe9\xab\x2b"
      "\xb5\xb1\xe1\x86\x72\x63\x1c\xdb\xd3\xe8\xb0\x5a\xcd\xd5\xff\x53\x99\xd6"
      "\x7f\x76\x2d\x1a\x73\x30\xb6\xe0\x34\xae\x50\xb2\xfe\x8f\xa4\x6b\xdb\x28"
      "\xaf\x2d\xaa\xff\x86\xc4\xb5\xf6\xa0\x5f\xd9\x45\xe6\x62\x35\x2a\xcf\x5d"
      "\x38\x3b\x3c\x3e\x5e\x9a\xe1\x80\x03\x0e\x38\x88\x0e\x5a\xfd\xc9\x84\x66"
      "\x70\xf3\x7f\x49\xa6\x9d\x05\xcf\xc2\x75\x4c\x30\xff\xaf\xab\x9e\xc5\x2b"
      "\xa6\x1b\xef\xc6\xf3\x7f\x5f\x5d\x1b\x69\xd1\xfc\xbf\x31\x71\xad\x2f\x58"
      "\xb5\x64\xd2\x52\x6e\x76\x62\x3a\xb3\x45\xca\x95\xe7\x2e\x3c\x35\x36\x31"
      "\x7c\xa6\x74\xa6\x34\xd9\x5b\xdc\xdb\xdd\xbd\xa7\xd8\xb3\xbf\x98\xc9\x86"
      "\x8b\xbb\xf8\xa8\xe1\xdc\xdd\x0f\x5c\xfd\xbf\x91\xe9\x87\xcc\x2f\xd1\x3e"
      "\xa6\x76\xfd\x37\xff\xfa\x3f\x5f\xd7\x46\x5a\x54\xff\x4d\xc9\x31\xd5\xac"
      "\x6b\x1a\x4e\xc5\xaa\xe4\xea\xdf\x2f\xd3\x1f\xd3\xd7\xa2\xfd\xe6\x9d\xd6"
      "\xff\xe1\xfe\xbf\xf3\xf1\xda\x36\xba\xff\x5a\x54\xff\xcd\x89\x6b\xed\x41"
      "\xbf\xd6\x2d\x32\x17\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
      "\xb0\x92\xe4\xcd\xd3\x1a\x99\xde\xdb\xf9\xa4\x85\xbf\x43\xd4\xc8\xcf\xff"
      "\x8d\xd4\xb5\x91\x16\xfd\xfc\x57\x47\xe2\xda\x48\x93\x7e\xaf\xa1\xe1\x24"
      "\x03\x00\x00\x00\x00\x00\x00\x00\x00\x34\x51\x4a\x9e\x3e\x92\x69\x87\x2a"
      "\x76\xc9\x5d\x58\x27\x1d\x49\xb6\xb8\xaf\xfd\x17\x00\x00\xff\xff\x7d\x77"
      "\x45\x2f",
      1190));
  NONFAILING(syz_mount_image(0x200004c0, 0x20000500, 0, 0x20000540, 1, 0x4a6,
                             0x20000580));
  NONFAILING(memcpy((void*)0x200004c0, "./file2\000", 8));
  NONFAILING(
      memcpy((void*)0x20000100,
             "./"
             "file2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\000",
             252));
  syscall(__NR_symlink, 0x200004c0ul, 0x20000100ul);
  NONFAILING(
      memcpy((void*)0x20000200,
             "./"
             "file2aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
             "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\000",
             252));
  NONFAILING(memcpy((void*)0x200000c0, "./file2\000", 8));
  inject_fault(13);
  syscall(__NR_rename, 0x20000200ul, 0x200000c0ul);
  return 0;
}