// https://syzkaller.appspot.com/bug?id=3543b2daaecd0dd430ea6fe8a8543ac1fd681e25
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <arpa/inet.h>
#include <dirent.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/prctl.h>
#include <sys/socket.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/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_bpf
#define __NR_bpf 321
#endif
#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 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 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_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 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 {
    unsigned long nb = a1;
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf) - 1);
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(nb % 10);
      nb /= 10;
    }
    return open(buf, a2, 0);
  }
}

static long syz_genetlink_get_family_id(volatile long name,
                                        volatile long sock_arg)
{
  int fd = sock_arg;
  if (fd < 0) {
    fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
    if (fd == -1) {
      return -1;
    }
  }
  struct nlmsg nlmsg_tmp;
  int ret = netlink_query_family_id(&nlmsg_tmp, fd, (char*)name, false);
  if ((int)sock_arg < 0)
    close(fd);
  if (ret < 0) {
    return -1;
  }
  return ret;
}

//% 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, max_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 void reset_loop_device(const char* loopname)
{
  int loopfd = open(loopname, O_RDWR);
  if (loopfd == -1) {
    return;
  }
  if (ioctl(loopfd, LOOP_CLR_FD, 0)) {
  }
  close(loopfd);
}

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, 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) {
    int loopfd;
    memset(loopname, 0, sizeof(loopname));
    snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid);
    if (setup_loop_device(data, size, loopname, &loopfd) == -1)
      return -1;
    close(loopfd);
    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");
  } else if (strncmp(fs, "gfs2", 4) == 0 &&
             (strstr(opts, "errors=panic") || strstr(opts, "debug"))) {
    strcat(opts, ",errors=withdraw");
  }
  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)
    reset_loop_device(loopname);
  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");
}

static void setup_sysctl()
{
  int cad_pid = fork();
  if (cad_pid < 0)
    exit(1);
  if (cad_pid == 0) {
    for (;;)
      sleep(100);
  }
  char tmppid[32];
  snprintf(tmppid, sizeof(tmppid), "%d", cad_pid);
  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", tmppid},
  };
  for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].name, files[i].data)) {
    }
  }
  kill(cad_pid, SIGKILL);
  while (waitpid(cad_pid, NULL, 0) != cad_pid)
    ;
}

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 (;;) {
      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;
    }
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  //  syz_mount_image$erofs arguments: [
  //    fs: ptr[in, buffer] {
  //      buffer: {65 72 6f 66 73 00} (length 0x6)
  //    }
  //    dir: ptr[in, buffer] {
  //      buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8)
  //    }
  //    flags: mount_flags = 0x810410 (8 bytes)
  //    opts: ptr[inout, array[ANYUNION]] {
  //      array[ANYUNION] {
  //      }
  //    }
  //    chdir: int8 = 0x1 (1 bytes)
  //    size: len = 0x1e1 (8 bytes)
  //    img: ptr[in, buffer] {
  //      buffer: (compressed buffer with length 0x1e1)
  //    }
  //  ]
  //  returns fd_dir
  NONFAILING(memcpy((void*)0x200000000080, "erofs\000", 6));
  NONFAILING(memcpy((void*)0x200000000200, "./file0\000", 8));
  NONFAILING(memcpy(
      (void*)0x200000000240,
      "\x78\x9c\xec\x99\xbf\xcf\xd2\x40\x18\xc7\xbf\x77\xed\x0b\xaf\x6f\x8c\x89"
      "\x8b\x83\x8b\x83\x18\x31\x4a\x69\x8b\x1a\x16\x06\x4c\xdc\x4d\xf0\xe7\x26"
      "\x91\x4a\xd0\x02\x06\x6a\x02\x24\x0e\xc4\xc5\xc5\xd1\xc1\xc4\xd5\x7f\xc0"
      "\xc1\x81\xc9\xc1\xcd\xcd\x55\x07\x35\x31\x71\x90\xd1\x49\x93\x9a\xbb\x1e"
      "\xed\xa5\xb5\x1a\x44\x06\xf3\x3e\x9f\x84\x87\xef\x3d\xf7\xeb\xb9\x6b\xf8"
      "\x92\x00\x08\x82\xd8\xb7\x7c\xfa\xf8\xed\xc3\xe3\x0b\xf5\xcb\x67\x00\x1c"
      "\x44\x09\x45\x95\xff\x62\x24\x63\xb8\x36\xfe\xfd\xd3\xfb\xa7\x9f\x34\x2e"
      "\x3e\x7b\xf1\xee\xf9\xeb\xc1\xa1\x07\x8b\xf4\x7a\xc5\x35\xf7\x17\xdb\xbc"
      "\x6a\x1a\x08\xf0\x3d\x0c\x43\x91\x89\xe2\x8a\x92\x8c\xcc\x14\x55\x94\x54"
      "\xee\x0a\x38\x4e\x29\x7d\x0d\x0c\x27\x94\xbe\x09\x8e\xab\x4a\x7b\x60\xb8"
      "\xa1\xf4\x1d\x4d\x0f\x0f\x28\xe1\x7b\xd6\xad\xa1\xdf\xb9\xdd\xf3\x3d\x5b"
      "\x04\x47\x04\x57\x84\x9a\xbe\xbf\x09\x60\x39\x67\xe8\x00\xd8\x95\xd5\x85"
      "\x21\xd3\xfa\xc7\xd3\xd9\xdd\xb6\xef\x7b\xa3\xb4\xd8\x09\x57\xfb\x64\xba"
      "\xd6\x15\xbf\xbb\x3f\x59\x5f\x93\xa3\xa1\xda\xa2\x3e\xf1\xbc\xae\x3f\x7a"
      "\x38\x17\x6d\x4b\xe5\x6d\xed\xfe\x1c\x70\x38\x4a\xd7\xc0\xd0\x52\xba\x8e"
      "\x22\x2c\xcb\x4a\xae\x44\x3b\xff\x51\x33\x59\xdf\xc8\x3d\x3f\xff\x07\xa7"
      "\x4d\x0b\xe3\xef\xa7\x1f\xae\x6c\xa1\x1e\x12\xff\xbb\x60\xe9\x8c\xf8\x40"
      "\xc7\x99\x23\xcb\xc5\x9b\xec\xac\xcf\x9b\xef\xce\xfe\x64\x19\xdb\x12\xd2"
      "\xb8\x00\x64\xba\xde\xee\x6d\xb6\x72\x41\x9d\xe8\x97\x63\x12\x7f\x12\xee"
      "\x7d\x52\xf3\x27\x13\x66\xec\x1f\xd5\xa0\x7f\xaf\x3a\x9e\xce\x2a\xbd\x7e"
      "\xbb\xeb\x75\xbd\x81\xeb\xd6\xce\xdb\x67\x6d\xfb\x9c\x5b\x95\x46\x14\xc5"
      "\x8c\xef\xfd\x88\xfd\x6f\x57\xfa\xd3\x9e\xb6\xfe\x4e\x8e\x57\x16\x58\x01"
      "\x93\x76\x10\x8c\x9c\x09\x10\x8c\x9c\xb8\xed\x46\x51\x73\xdc\xd6\xcb\xe1"
      "\x57\x39\x87\x4b\xff\xe3\x28\x1f\x8f\xd6\x10\x0f\x51\x1e\x3b\xe7\x8b\x8e"
      "\xa9\x17\x97\xef\x42\x95\x8d\x9c\x72\x08\x82\x20\x08\x82\x20\x08\x82\x20"
      "\x08\x82\x20\x08\x82\x20\xd6\xe4\x18\x98\xfc\x15\x54\xfd\x51\x15\xe6\xe0"
      "\x5e\x92\xa3\x7f\x06\x00\x00\xff\xff\x3a\x56\x65\xb1",
      481));
  NONFAILING(syz_mount_image(
      /*fs=*/0x200000000080, /*dir=*/0x200000000200,
      /*flags=MS_I_VERSION|MS_POSIXACL|MS_SYNCHRONOUS|MS_NOATIME*/ 0x810410,
      /*opts=*/0x2000000000c0, /*chdir=*/1, /*size=*/0x1e1,
      /*img=*/0x200000000240));
  //  socket arguments: [
  //    domain: socket_domain = 0x11 (8 bytes)
  //    type: socket_type = 0x3 (8 bytes)
  //    proto: int32 = 0x0 (4 bytes)
  //  ]
  //  returns sock
  syscall(__NR_socket, /*domain=AF_PACKET*/ 0x11ul, /*type=SOCK_RAW*/ 3ul,
          /*proto=*/0);
  //  openat$dir arguments: [
  //    fd: const = 0xffffffffffffff9c (8 bytes)
  //    file: ptr[in, buffer] {
  //      buffer: {2e 00} (length 0x2)
  //    }
  //    flags: open_flags = 0x0 (4 bytes)
  //    mode: open_mode = 0x0 (2 bytes)
  //  ]
  //  returns fd_dir
  NONFAILING(memcpy((void*)0x2000000002c0, ".\000", 2));
  res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul,
                /*file=*/0x2000000002c0ul, /*flags=*/0, /*mode=*/0);
  if (res != -1)
    r[0] = res;
  //  prlimit64 arguments: [
  //    pid: pid (resource)
  //    res: rlimit_type = 0xe (8 bytes)
  //    new: ptr[in, rlimit] {
  //      rlimit {
  //        soft: intptr = 0x8 (8 bytes)
  //        hard: intptr = 0x8b (8 bytes)
  //      }
  //    }
  //    old: nil
  //  ]
  NONFAILING(*(uint64_t*)0x200000000140 = 8);
  NONFAILING(*(uint64_t*)0x200000000148 = 0x8b);
  syscall(__NR_prlimit64, /*pid=*/0, /*res=RLIMIT_RTPRIO*/ 0xeul,
          /*new=*/0x200000000140ul, /*old=*/0ul);
  //  socket$inet_icmp_raw arguments: [
  //    domain: const = 0x2 (8 bytes)
  //    type: const = 0x3 (8 bytes)
  //    proto: const = 0x1 (4 bytes)
  //  ]
  //  returns sock_icmp
  syscall(__NR_socket, /*domain=*/2ul, /*type=*/3ul, /*proto=*/1);
  //  prctl$PR_SCHED_CORE arguments: [
  //    option: const = 0x3e (8 bytes)
  //    cmd: intptr = 0x10000000001 (8 bytes)
  //    pid: pid (resource)
  //    type: pid_type = 0x2 (8 bytes)
  //    uaddr: nil
  //  ]
  syscall(__NR_prctl, /*option=*/0x3eul, /*cmd=*/0x10000000001ul, /*pid=*/0,
          /*type=PIDTYPE_PGID*/ 2ul, /*uaddr=*/0ul);
  //  sched_setscheduler arguments: [
  //    pid: pid (resource)
  //    policy: sched_policy = 0x1 (8 bytes)
  //    prio: ptr[in, int32] {
  //      int32 = 0x1 (4 bytes)
  //    }
  //  ]
  NONFAILING(*(uint32_t*)0x200000000080 = 1);
  syscall(__NR_sched_setscheduler, /*pid=*/0, /*policy=SCHED_FIFO*/ 1ul,
          /*prio=*/0x200000000080ul);
  //  syz_open_dev$MSR arguments: [
  //    dev: nil
  //    id: intptr = 0x0 (8 bytes)
  //    flags: const = 0x0 (8 bytes)
  //  ]
  //  returns fd_msr
  NONFAILING(syz_open_dev(/*dev=*/0, /*id=*/0, /*flags=*/0));
  //  setsockopt$inet_mreqn arguments: [
  //    fd: sock_in (resource)
  //    level: const = 0x0 (4 bytes)
  //    optname: sockopt_opt_ip_mreq = 0x20 (4 bytes)
  //    optval: nil
  //    optlen: len = 0x300 (8 bytes)
  //  ]
  syscall(__NR_setsockopt, /*fd=*/(intptr_t)-1, /*level=*/0,
          /*optname=IP_MULTICAST_IF*/ 0x20, /*optval=*/0ul, /*optlen=*/0x300ul);
  //  socket arguments: [
  //    domain: socket_domain = 0x10 (8 bytes)
  //    type: socket_type = 0x3 (8 bytes)
  //    proto: int32 = 0x0 (4 bytes)
  //  ]
  //  returns sock
  syscall(__NR_socket, /*domain=AF_NETLINK*/ 0x10ul, /*type=SOCK_RAW*/ 3ul,
          /*proto=*/0);
  //  bpf$MAP_CREATE arguments: [
  //    cmd: const = 0x0 (8 bytes)
  //    arg: nil
  //    size: len = 0x0 (8 bytes)
  //  ]
  //  returns fd_bpf_map
  syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0ul, /*size=*/0ul);
  //  syz_genetlink_get_family_id$nl80211 arguments: [
  //    name: nil
  //    fd: sock_nl_generic (resource)
  //  ]
  //  returns nl80211_family_id
  NONFAILING(syz_genetlink_get_family_id(/*name=*/0, /*fd=*/-1));
  //  getdents64 arguments: [
  //    fd: fd_dir (resource)
  //    ent: nil
  //    count: len = 0x0 (8 bytes)
  //  ]
  syscall(__NR_getdents64, /*fd=*/r[0], /*ent=*/0ul, /*count=*/0ul);
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul,
          /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul,
          /*fd=*/(intptr_t)-1, /*offset=*/0ul);
  setup_sysctl();
  const char* reason;
  (void)reason;
  install_segv_handler();
  for (procid = 0; procid < 5; procid++) {
    if (fork() == 0) {
      loop();
    }
  }
  sleep(1000000);
  return 0;
}