// https://syzkaller.appspot.com/bug?id=8cb5c46dff156b1f22ead052ffd8e29cc44b03c1
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <dirent.h>
#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sched.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/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

#include <linux/capability.h>
#include <linux/net.h>
#include <linux/usb/ch9.h>

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 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;
}

#define USB_DEBUG 0

#define USB_MAX_EP_NUM 32

struct usb_device_index {
  struct usb_device_descriptor* dev;
  struct usb_config_descriptor* config;
  unsigned config_length;
  struct usb_interface_descriptor* iface;
  struct usb_endpoint_descriptor* eps[USB_MAX_EP_NUM];
  unsigned eps_num;
};

static bool parse_usb_descriptor(char* buffer, size_t length,
                                 struct usb_device_index* index)
{
  if (length <
      sizeof(*index->dev) + sizeof(*index->config) + sizeof(*index->iface))
    return false;
  index->dev = (struct usb_device_descriptor*)buffer;
  index->config = (struct usb_config_descriptor*)(buffer + sizeof(*index->dev));
  index->config_length = length - sizeof(*index->dev);
  index->iface =
      (struct usb_interface_descriptor*)(buffer + sizeof(*index->dev) +
                                         sizeof(*index->config));
  index->eps_num = 0;
  size_t offset = 0;
  while (true) {
    if (offset + 1 >= length)
      break;
    uint8_t desc_length = buffer[offset];
    uint8_t desc_type = buffer[offset + 1];
    if (desc_length <= 2)
      break;
    if (offset + desc_length > length)
      break;
    if (desc_type == USB_DT_ENDPOINT) {
      index->eps[index->eps_num] =
          (struct usb_endpoint_descriptor*)(buffer + offset);
      index->eps_num++;
    }
    if (index->eps_num == USB_MAX_EP_NUM)
      break;
    offset += desc_length;
  }
  return true;
}

enum usb_fuzzer_event_type {
  USB_FUZZER_EVENT_INVALID,
  USB_FUZZER_EVENT_CONNECT,
  USB_FUZZER_EVENT_DISCONNECT,
  USB_FUZZER_EVENT_SUSPEND,
  USB_FUZZER_EVENT_RESUME,
  USB_FUZZER_EVENT_CONTROL,
};

struct usb_fuzzer_event {
  uint32_t type;
  uint32_t length;
  char data[0];
};

struct usb_fuzzer_init {
  uint64_t speed;
  const char* driver_name;
  const char* device_name;
};

struct usb_fuzzer_ep_io {
  uint16_t ep;
  uint16_t flags;
  uint32_t length;
  char data[0];
};

#define USB_FUZZER_IOCTL_INIT _IOW('U', 0, struct usb_fuzzer_init)
#define USB_FUZZER_IOCTL_RUN _IO('U', 1)
#define USB_FUZZER_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_fuzzer_event)
#define USB_FUZZER_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP0_READ _IOWR('U', 4, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor)
#define USB_FUZZER_IOCTL_EP_WRITE _IOW('U', 7, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_EP_READ _IOWR('U', 8, struct usb_fuzzer_ep_io)
#define USB_FUZZER_IOCTL_CONFIGURE _IO('U', 9)
#define USB_FUZZER_IOCTL_VBUS_DRAW _IOW('U', 10, uint32_t)

int usb_fuzzer_open()
{
  return open("/sys/kernel/debug/usb-fuzzer", O_RDWR);
}

int usb_fuzzer_init(int fd, uint32_t speed, const char* driver,
                    const char* device)
{
  struct usb_fuzzer_init arg;
  arg.speed = speed;
  arg.driver_name = driver;
  arg.device_name = device;
  return ioctl(fd, USB_FUZZER_IOCTL_INIT, &arg);
}

int usb_fuzzer_run(int fd)
{
  return ioctl(fd, USB_FUZZER_IOCTL_RUN, 0);
}

int usb_fuzzer_event_fetch(int fd, struct usb_fuzzer_event* event)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EVENT_FETCH, event);
}

int usb_fuzzer_ep0_write(int fd, struct usb_fuzzer_ep_io* io)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EP0_WRITE, io);
}

int usb_fuzzer_ep0_read(int fd, struct usb_fuzzer_ep_io* io)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EP0_READ, io);
}

int usb_fuzzer_ep_write(int fd, struct usb_fuzzer_ep_io* io)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EP_WRITE, io);
}

int usb_fuzzer_ep_read(int fd, struct usb_fuzzer_ep_io* io)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EP_READ, io);
}

int usb_fuzzer_ep_enable(int fd, struct usb_endpoint_descriptor* desc)
{
  return ioctl(fd, USB_FUZZER_IOCTL_EP_ENABLE, desc);
}

int usb_fuzzer_configure(int fd)
{
  return ioctl(fd, USB_FUZZER_IOCTL_CONFIGURE, 0);
}

int usb_fuzzer_vbus_draw(int fd, uint32_t power)
{
  return ioctl(fd, USB_FUZZER_IOCTL_VBUS_DRAW, power);
}

#define USB_MAX_PACKET_SIZE 1024

struct usb_fuzzer_control_event {
  struct usb_fuzzer_event inner;
  struct usb_ctrlrequest ctrl;
  char data[USB_MAX_PACKET_SIZE];
};

struct usb_fuzzer_ep_io_data {
  struct usb_fuzzer_ep_io inner;
  char data[USB_MAX_PACKET_SIZE];
};

struct vusb_connect_string_descriptor {
  uint32_t len;
  char* str;
} __attribute__((packed));

struct vusb_connect_descriptors {
  uint32_t qual_len;
  char* qual;
  uint32_t bos_len;
  char* bos;
  uint32_t strs_len;
  struct vusb_connect_string_descriptor strs[0];
} __attribute__((packed));

static const char* default_string = "syzkaller";

static bool lookup_connect_response(struct vusb_connect_descriptors* descs,
                                    struct usb_device_index* index,
                                    struct usb_ctrlrequest* ctrl,
                                    char** response_data,
                                    uint32_t* response_length)
{
  uint8_t str_idx;
  switch (ctrl->bRequestType & USB_TYPE_MASK) {
  case USB_TYPE_STANDARD:
    switch (ctrl->bRequest) {
    case USB_REQ_GET_DESCRIPTOR:
      switch (ctrl->wValue >> 8) {
      case USB_DT_DEVICE:
        *response_data = (char*)index->dev;
        *response_length = sizeof(*index->dev);
        return true;
      case USB_DT_CONFIG:
        *response_data = (char*)index->config;
        *response_length = index->config_length;
        return true;
      case USB_DT_STRING:
        str_idx = (uint8_t)ctrl->wValue;
        if (!descs || str_idx >= descs->strs_len) {
          *response_data = (char*)default_string;
          *response_length = strlen(default_string);
        } else {
          *response_data = descs->strs[str_idx].str;
          *response_length = descs->strs[str_idx].len;
        }
        return true;
      case USB_DT_BOS:
        *response_data = descs->bos;
        *response_length = descs->bos_len;
        return true;
      case USB_DT_DEVICE_QUALIFIER:
        *response_data = descs->qual;
        *response_length = descs->qual_len;
        return true;
      default:
        exit(1);
        return false;
      }
      break;
    default:
      exit(1);
      return false;
    }
    break;
  default:
    exit(1);
    return false;
  }
  return false;
}

static volatile long syz_usb_connect(volatile long a0, volatile long a1,
                                     volatile long a2, volatile long a3)
{
  uint64_t speed = a0;
  uint64_t dev_len = a1;
  char* dev = (char*)a2;
  struct vusb_connect_descriptors* descs = (struct vusb_connect_descriptors*)a3;
  if (!dev) {
    return -1;
  }
  struct usb_device_index index;
  memset(&index, 0, sizeof(index));
  int rv = 0;
  NONFAILING(rv = parse_usb_descriptor(dev, dev_len, &index));
  if (!rv) {
    return rv;
  }
  int fd = usb_fuzzer_open();
  if (fd < 0) {
    return fd;
  }
  char device[32];
  sprintf(&device[0], "dummy_udc.%llu", procid);
  rv = usb_fuzzer_init(fd, speed, "dummy_udc", &device[0]);
  if (rv < 0) {
    return rv;
  }
  rv = usb_fuzzer_run(fd);
  if (rv < 0) {
    return rv;
  }
  bool done = false;
  while (!done) {
    struct usb_fuzzer_control_event event;
    event.inner.type = 0;
    event.inner.length = sizeof(event.ctrl);
    rv = usb_fuzzer_event_fetch(fd, (struct usb_fuzzer_event*)&event);
    if (rv < 0) {
      return rv;
    }
    if (event.inner.type != USB_FUZZER_EVENT_CONTROL)
      continue;
    bool response_found = false;
    char* response_data = NULL;
    uint32_t response_length = 0;
    if (event.ctrl.bRequestType & USB_DIR_IN) {
      NONFAILING(response_found =
                     lookup_connect_response(descs, &index, &event.ctrl,
                                             &response_data, &response_length));
      if (!response_found) {
        return -1;
      }
    } else {
      if ((event.ctrl.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD ||
          event.ctrl.bRequest != USB_REQ_SET_CONFIGURATION) {
        exit(1);
        return -1;
      }
      done = true;
    }
    if (done) {
      rv = usb_fuzzer_vbus_draw(fd, index.config->bMaxPower);
      if (rv < 0) {
        return rv;
      }
      rv = usb_fuzzer_configure(fd);
      if (rv < 0) {
        return rv;
      }
      unsigned ep;
      for (ep = 0; ep < index.eps_num; ep++) {
        rv = usb_fuzzer_ep_enable(fd, index.eps[ep]);
        if (rv < 0) {
        } else {
        }
      }
    }
    struct usb_fuzzer_ep_io_data response;
    response.inner.ep = 0;
    response.inner.flags = 0;
    if (response_length > sizeof(response.data))
      response_length = 0;
    if (event.ctrl.wLength < response_length)
      response_length = event.ctrl.wLength;
    response.inner.length = response_length;
    if (response_data)
      memcpy(&response.data[0], response_data, response_length);
    else
      memset(&response.data[0], 0, response_length);
    if (event.ctrl.bRequestType & USB_DIR_IN) {
      rv = usb_fuzzer_ep0_write(fd, (struct usb_fuzzer_ep_io*)&response);
    } else {
      rv = usb_fuzzer_ep0_read(fd, (struct usb_fuzzer_ep_io*)&response);
    }
    if (rv < 0) {
      return rv;
    }
  }
  sleep_ms(200);
  return fd;
}

static volatile long syz_usb_ep_write(volatile long a0, volatile long a1,
                                      volatile long a2, volatile long a3)
{
  int fd = a0;
  uint16_t ep = a1;
  uint32_t len = a2;
  char* data = (char*)a3;
  struct usb_fuzzer_ep_io_data io_data;
  io_data.inner.ep = ep;
  io_data.inner.flags = 0;
  if (len > sizeof(io_data.data))
    len = sizeof(io_data.data);
  io_data.inner.length = len;
  NONFAILING(memcpy(&io_data.data[0], data, len));
  int rv = usb_fuzzer_ep_write(fd, (struct usb_fuzzer_ep_io*)&io_data);
  if (rv < 0) {
    return rv;
  }
  sleep_ms(200);
  return 0;
}

#define XT_TABLE_SIZE 1536
#define XT_MAX_ENTRIES 10

struct xt_counters {
  uint64_t pcnt, bcnt;
};

struct ipt_getinfo {
  char name[32];
  unsigned int valid_hooks;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_entries;
  unsigned int size;
};

struct ipt_get_entries {
  char name[32];
  unsigned int size;
  void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};

struct ipt_replace {
  char name[32];
  unsigned int valid_hooks;
  unsigned int num_entries;
  unsigned int size;
  unsigned int hook_entry[5];
  unsigned int underflow[5];
  unsigned int num_counters;
  struct xt_counters* counters;
  char entrytable[XT_TABLE_SIZE];
};

struct ipt_table_desc {
  const char* name;
  struct ipt_getinfo info;
  struct ipt_replace replace;
};

static struct ipt_table_desc ipv4_tables[] = {
    {.name = "filter"}, {.name = "nat"},      {.name = "mangle"},
    {.name = "raw"},    {.name = "security"},
};

static struct ipt_table_desc ipv6_tables[] = {
    {.name = "filter"}, {.name = "nat"},      {.name = "mangle"},
    {.name = "raw"},    {.name = "security"},
};

#define IPT_BASE_CTL 64
#define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
#define IPT_SO_GET_INFO (IPT_BASE_CTL)
#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)

struct arpt_getinfo {
  char name[32];
  unsigned int valid_hooks;
  unsigned int hook_entry[3];
  unsigned int underflow[3];
  unsigned int num_entries;
  unsigned int size;
};

struct arpt_get_entries {
  char name[32];
  unsigned int size;
  void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};

struct arpt_replace {
  char name[32];
  unsigned int valid_hooks;
  unsigned int num_entries;
  unsigned int size;
  unsigned int hook_entry[3];
  unsigned int underflow[3];
  unsigned int num_counters;
  struct xt_counters* counters;
  char entrytable[XT_TABLE_SIZE];
};

struct arpt_table_desc {
  const char* name;
  struct arpt_getinfo info;
  struct arpt_replace replace;
};

static struct arpt_table_desc arpt_tables[] = {
    {.name = "filter"},
};

#define ARPT_BASE_CTL 96
#define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL)
#define ARPT_SO_GET_INFO (ARPT_BASE_CTL)
#define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1)

static void checkpoint_iptables(struct ipt_table_desc* tables, int num_tables,
                                int family, int level)
{
  struct ipt_get_entries entries;
  socklen_t optlen;
  int fd, i;
  fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < num_tables; i++) {
    struct ipt_table_desc* table = &tables[i];
    strcpy(table->info.name, table->name);
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->info);
    if (getsockopt(fd, level, IPT_SO_GET_INFO, &table->info, &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      exit(1);
    }
    if (table->info.size > sizeof(table->replace.entrytable))
      exit(1);
    if (table->info.num_entries > XT_MAX_ENTRIES)
      exit(1);
    memset(&entries, 0, sizeof(entries));
    strcpy(entries.name, table->name);
    entries.size = table->info.size;
    optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
    if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
      exit(1);
    table->replace.valid_hooks = table->info.valid_hooks;
    table->replace.num_entries = table->info.num_entries;
    table->replace.size = table->info.size;
    memcpy(table->replace.hook_entry, table->info.hook_entry,
           sizeof(table->replace.hook_entry));
    memcpy(table->replace.underflow, table->info.underflow,
           sizeof(table->replace.underflow));
    memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
  }
  close(fd);
}

static void reset_iptables(struct ipt_table_desc* tables, int num_tables,
                           int family, int level)
{
  struct xt_counters counters[XT_MAX_ENTRIES];
  struct ipt_get_entries entries;
  struct ipt_getinfo info;
  socklen_t optlen;
  int fd, i;
  fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < num_tables; i++) {
    struct ipt_table_desc* table = &tables[i];
    if (table->info.valid_hooks == 0)
      continue;
    memset(&info, 0, sizeof(info));
    strcpy(info.name, table->name);
    optlen = sizeof(info);
    if (getsockopt(fd, level, IPT_SO_GET_INFO, &info, &optlen))
      exit(1);
    if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
      memset(&entries, 0, sizeof(entries));
      strcpy(entries.name, table->name);
      entries.size = table->info.size;
      optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
      if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
        exit(1);
      if (memcmp(table->replace.entrytable, entries.entrytable,
                 table->info.size) == 0)
        continue;
    }
    table->replace.num_counters = info.num_entries;
    table->replace.counters = counters;
    optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
             table->replace.size;
    if (setsockopt(fd, level, IPT_SO_SET_REPLACE, &table->replace, optlen))
      exit(1);
  }
  close(fd);
}

static void checkpoint_arptables(void)
{
  struct arpt_get_entries entries;
  socklen_t optlen;
  unsigned i;
  int fd;
  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
    struct arpt_table_desc* table = &arpt_tables[i];
    strcpy(table->info.name, table->name);
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->info);
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &table->info, &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      exit(1);
    }
    if (table->info.size > sizeof(table->replace.entrytable))
      exit(1);
    if (table->info.num_entries > XT_MAX_ENTRIES)
      exit(1);
    memset(&entries, 0, sizeof(entries));
    strcpy(entries.name, table->name);
    entries.size = table->info.size;
    optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
      exit(1);
    table->replace.valid_hooks = table->info.valid_hooks;
    table->replace.num_entries = table->info.num_entries;
    table->replace.size = table->info.size;
    memcpy(table->replace.hook_entry, table->info.hook_entry,
           sizeof(table->replace.hook_entry));
    memcpy(table->replace.underflow, table->info.underflow,
           sizeof(table->replace.underflow));
    memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
  }
  close(fd);
}

static void reset_arptables()
{
  struct xt_counters counters[XT_MAX_ENTRIES];
  struct arpt_get_entries entries;
  struct arpt_getinfo info;
  socklen_t optlen;
  unsigned i;
  int fd;
  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
    struct arpt_table_desc* table = &arpt_tables[i];
    if (table->info.valid_hooks == 0)
      continue;
    memset(&info, 0, sizeof(info));
    strcpy(info.name, table->name);
    optlen = sizeof(info);
    if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &info, &optlen))
      exit(1);
    if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
      memset(&entries, 0, sizeof(entries));
      strcpy(entries.name, table->name);
      entries.size = table->info.size;
      optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
      if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
        exit(1);
      if (memcmp(table->replace.entrytable, entries.entrytable,
                 table->info.size) == 0)
        continue;
    } else {
    }
    table->replace.num_counters = info.num_entries;
    table->replace.counters = counters;
    optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
             table->replace.size;
    if (setsockopt(fd, SOL_IP, ARPT_SO_SET_REPLACE, &table->replace, optlen))
      exit(1);
  }
  close(fd);
}

#define NF_BR_NUMHOOKS 6
#define EBT_TABLE_MAXNAMELEN 32
#define EBT_CHAIN_MAXNAMELEN 32
#define EBT_BASE_CTL 128
#define EBT_SO_SET_ENTRIES (EBT_BASE_CTL)
#define EBT_SO_GET_INFO (EBT_BASE_CTL)
#define EBT_SO_GET_ENTRIES (EBT_SO_GET_INFO + 1)
#define EBT_SO_GET_INIT_INFO (EBT_SO_GET_ENTRIES + 1)
#define EBT_SO_GET_INIT_ENTRIES (EBT_SO_GET_INIT_INFO + 1)

struct ebt_replace {
  char name[EBT_TABLE_MAXNAMELEN];
  unsigned int valid_hooks;
  unsigned int nentries;
  unsigned int entries_size;
  struct ebt_entries* hook_entry[NF_BR_NUMHOOKS];
  unsigned int num_counters;
  struct ebt_counter* counters;
  char* entries;
};

struct ebt_entries {
  unsigned int distinguisher;
  char name[EBT_CHAIN_MAXNAMELEN];
  unsigned int counter_offset;
  int policy;
  unsigned int nentries;
  char data[0] __attribute__((aligned(__alignof__(struct ebt_replace))));
};

struct ebt_table_desc {
  const char* name;
  struct ebt_replace replace;
  char entrytable[XT_TABLE_SIZE];
};

static struct ebt_table_desc ebt_tables[] = {
    {.name = "filter"}, {.name = "nat"}, {.name = "broute"},
};

static void checkpoint_ebtables(void)
{
  socklen_t optlen;
  unsigned i;
  int fd;
  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) {
    struct ebt_table_desc* table = &ebt_tables[i];
    strcpy(table->replace.name, table->name);
    optlen = sizeof(table->replace);
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_INFO, &table->replace,
                   &optlen)) {
      switch (errno) {
      case EPERM:
      case ENOENT:
      case ENOPROTOOPT:
        continue;
      }
      exit(1);
    }
    if (table->replace.entries_size > sizeof(table->entrytable))
      exit(1);
    table->replace.num_counters = 0;
    table->replace.entries = table->entrytable;
    optlen = sizeof(table->replace) + table->replace.entries_size;
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_ENTRIES, &table->replace,
                   &optlen))
      exit(1);
  }
  close(fd);
}

static void reset_ebtables()
{
  struct ebt_replace replace;
  char entrytable[XT_TABLE_SIZE];
  socklen_t optlen;
  unsigned i, j, h;
  int fd;
  fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (fd == -1) {
    switch (errno) {
    case EAFNOSUPPORT:
    case ENOPROTOOPT:
      return;
    }
    exit(1);
  }
  for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) {
    struct ebt_table_desc* table = &ebt_tables[i];
    if (table->replace.valid_hooks == 0)
      continue;
    memset(&replace, 0, sizeof(replace));
    strcpy(replace.name, table->name);
    optlen = sizeof(replace);
    if (getsockopt(fd, SOL_IP, EBT_SO_GET_INFO, &replace, &optlen))
      exit(1);
    replace.num_counters = 0;
    table->replace.entries = 0;
    for (h = 0; h < NF_BR_NUMHOOKS; h++)
      table->replace.hook_entry[h] = 0;
    if (memcmp(&table->replace, &replace, sizeof(table->replace)) == 0) {
      memset(&entrytable, 0, sizeof(entrytable));
      replace.entries = entrytable;
      optlen = sizeof(replace) + replace.entries_size;
      if (getsockopt(fd, SOL_IP, EBT_SO_GET_ENTRIES, &replace, &optlen))
        exit(1);
      if (memcmp(table->entrytable, entrytable, replace.entries_size) == 0)
        continue;
    }
    for (j = 0, h = 0; h < NF_BR_NUMHOOKS; h++) {
      if (table->replace.valid_hooks & (1 << h)) {
        table->replace.hook_entry[h] =
            (struct ebt_entries*)table->entrytable + j;
        j++;
      }
    }
    table->replace.entries = table->entrytable;
    optlen = sizeof(table->replace) + table->replace.entries_size;
    if (setsockopt(fd, SOL_IP, EBT_SO_SET_ENTRIES, &table->replace, optlen))
      exit(1);
  }
  close(fd);
}

static void checkpoint_net_namespace(void)
{
  checkpoint_ebtables();
  checkpoint_arptables();
  checkpoint_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
                      AF_INET, SOL_IP);
  checkpoint_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
                      AF_INET6, SOL_IPV6);
}

static void reset_net_namespace(void)
{
  reset_ebtables();
  reset_arptables();
  reset_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
                 AF_INET, SOL_IP);
  reset_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
                 AF_INET6, SOL_IPV6);
}

static void setup_cgroups()
{
  if (mkdir("/syzcgroup", 0777)) {
  }
  if (mkdir("/syzcgroup/unified", 0777)) {
  }
  if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) {
  }
  if (chmod("/syzcgroup/unified", 0777)) {
  }
  write_file("/syzcgroup/unified/cgroup.subtree_control",
             "+cpu +memory +io +pids +rdma");
  if (mkdir("/syzcgroup/cpu", 0777)) {
  }
  if (mount("none", "/syzcgroup/cpu", "cgroup", 0,
            "cpuset,cpuacct,perf_event,hugetlb")) {
  }
  write_file("/syzcgroup/cpu/cgroup.clone_children", "1");
  if (chmod("/syzcgroup/cpu", 0777)) {
  }
  if (mkdir("/syzcgroup/net", 0777)) {
  }
  if (mount("none", "/syzcgroup/net", "cgroup", 0,
            "net_cls,net_prio,devices,freezer")) {
  }
  if (chmod("/syzcgroup/net", 0777)) {
  }
}

static void setup_cgroups_loop()
{
  int pid = getpid();
  char file[128];
  char cgroupdir[64];
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
  if (mkdir(cgroupdir, 0777)) {
  }
  snprintf(file, sizeof(file), "%s/pids.max", cgroupdir);
  write_file(file, "32");
  snprintf(file, sizeof(file), "%s/memory.low", cgroupdir);
  write_file(file, "%d", 298 << 20);
  snprintf(file, sizeof(file), "%s/memory.high", cgroupdir);
  write_file(file, "%d", 299 << 20);
  snprintf(file, sizeof(file), "%s/memory.max", cgroupdir);
  write_file(file, "%d", 300 << 20);
  snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
  write_file(file, "%d", pid);
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
  if (mkdir(cgroupdir, 0777)) {
  }
  snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
  write_file(file, "%d", pid);
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
  if (mkdir(cgroupdir, 0777)) {
  }
  snprintf(file, sizeof(file), "%s/cgroup.procs", cgroupdir);
  write_file(file, "%d", pid);
}

static void setup_cgroups_test()
{
  char cgroupdir[64];
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
  if (symlink(cgroupdir, "./cgroup")) {
  }
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/cpu/syz%llu", procid);
  if (symlink(cgroupdir, "./cgroup.cpu")) {
  }
  snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/net/syz%llu", procid);
  if (symlink(cgroupdir, "./cgroup.net")) {
  }
}

static void setup_common()
{
  if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) {
  }
  setup_cgroups();
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setsid();
  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = (200 << 20);
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 32 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 136 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 0;
  setrlimit(RLIMIT_CORE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (unshare(CLONE_NEWIPC)) {
  }
  if (unshare(0x02000000)) {
  }
  if (unshare(CLONE_NEWUTS)) {
  }
  if (unshare(CLONE_SYSVSEM)) {
  }
  typedef struct {
    const char* name;
    const char* value;
  } sysctl_t;
  static const sysctl_t sysctls[] = {
      {"/proc/sys/kernel/shmmax", "16777216"},
      {"/proc/sys/kernel/shmall", "536870912"},
      {"/proc/sys/kernel/shmmni", "1024"},
      {"/proc/sys/kernel/msgmax", "8192"},
      {"/proc/sys/kernel/msgmni", "1024"},
      {"/proc/sys/kernel/msgmnb", "1024"},
      {"/proc/sys/kernel/sem", "1024 1048576 500 1024"},
  };
  unsigned i;
  for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++)
    write_file(sysctls[i].name, sysctls[i].value);
}

int wait_for_loop(int pid)
{
  if (pid < 0)
    exit(1);
  int status = 0;
  while (waitpid(-1, &status, __WALL) != pid) {
  }
  return WEXITSTATUS(status);
}

static void drop_caps(void)
{
  struct __user_cap_header_struct cap_hdr = {};
  struct __user_cap_data_struct cap_data[2] = {};
  cap_hdr.version = _LINUX_CAPABILITY_VERSION_3;
  cap_hdr.pid = getpid();
  if (syscall(SYS_capget, &cap_hdr, &cap_data))
    exit(1);
  const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE);
  cap_data[0].effective &= ~drop;
  cap_data[0].permitted &= ~drop;
  cap_data[0].inheritable &= ~drop;
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    exit(1);
}

static int do_sandbox_none(void)
{
  if (unshare(CLONE_NEWPID)) {
  }
  int pid = fork();
  if (pid != 0)
    return wait_for_loop(pid);
  setup_common();
  sandbox_common();
  drop_caps();
  if (unshare(CLONE_NEWNET)) {
  }
  loop();
  exit(1);
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  while (umount2(dir, MNT_DETACH) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exit(1);
    }
    exit(1);
  }
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    while (umount2(filename, MNT_DETACH) == 0) {
    }
    struct stat st;
    if (lstat(filename, &st))
      exit(1);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EPERM) {
        int fd = open(filename, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
            close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exit(1);
      if (umount2(filename, MNT_DETACH))
        exit(1);
    }
  }
  closedir(dp);
  int i;
  for (i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EPERM) {
        int fd = open(dir, O_RDONLY);
        if (fd != -1) {
          long flags = 0;
          if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0)
            close(fd);
          continue;
        }
      }
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH))
          exit(1);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exit(1);
  }
}

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 setup_loop()
{
  setup_cgroups_loop();
  checkpoint_net_namespace();
}

static void reset_loop()
{
  reset_net_namespace();
}

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

static void close_fds()
{
  int fd;
  for (fd = 3; fd < 30; fd++)
    close(fd);
}

static void setup_binfmt_misc()
{
  if (mount(0, "/proc/sys/fs/binfmt_misc", "binfmt_misc", 0, 0)) {
  }
  write_file("/proc/sys/fs/binfmt_misc/register", ":syz0:M:0:\x01::./file0:");
  write_file("/proc/sys/fs/binfmt_misc/register",
             ":syz1:M:1:\x02::./file0:POC");
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  setup_loop();
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    reset_loop();
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      if (chdir(cwdbuf))
        exit(1);
      setup_test();
      execute_one();
      close_fds();
      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;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[1] = {0xffffffffffffffff};

void execute_one(void)
{
  intptr_t res = 0;
  NONFAILING(*(uint8_t*)0x200001c0 = 0x12);
  NONFAILING(*(uint8_t*)0x200001c1 = 1);
  NONFAILING(*(uint16_t*)0x200001c2 = 0);
  NONFAILING(*(uint8_t*)0x200001c4 = 4);
  NONFAILING(*(uint8_t*)0x200001c5 = 0xe1);
  NONFAILING(*(uint8_t*)0x200001c6 = 0x34);
  NONFAILING(*(uint8_t*)0x200001c7 = 8);
  NONFAILING(*(uint16_t*)0x200001c8 = 0x5ac);
  NONFAILING(*(uint16_t*)0x200001ca = 0x9219);
  NONFAILING(*(uint16_t*)0x200001cc = 0x7d82);
  NONFAILING(*(uint8_t*)0x200001ce = 0);
  NONFAILING(*(uint8_t*)0x200001cf = 0);
  NONFAILING(*(uint8_t*)0x200001d0 = 0);
  NONFAILING(*(uint8_t*)0x200001d1 = 1);
  NONFAILING(*(uint8_t*)0x200001d2 = 9);
  NONFAILING(*(uint8_t*)0x200001d3 = 2);
  NONFAILING(*(uint16_t*)0x200001d4 = 0x1b);
  NONFAILING(*(uint8_t*)0x200001d6 = 1);
  NONFAILING(*(uint8_t*)0x200001d7 = 0);
  NONFAILING(*(uint8_t*)0x200001d8 = 0);
  NONFAILING(*(uint8_t*)0x200001d9 = 0);
  NONFAILING(*(uint8_t*)0x200001da = 0);
  NONFAILING(*(uint8_t*)0x200001db = 9);
  NONFAILING(*(uint8_t*)0x200001dc = 4);
  NONFAILING(*(uint8_t*)0x200001dd = 0x10);
  NONFAILING(*(uint8_t*)0x200001de = 0);
  NONFAILING(*(uint8_t*)0x200001df = 1);
  NONFAILING(*(uint8_t*)0x200001e0 = 3);
  NONFAILING(*(uint8_t*)0x200001e1 = 0xb8);
  NONFAILING(*(uint8_t*)0x200001e2 = 0);
  NONFAILING(*(uint8_t*)0x200001e3 = 0);
  NONFAILING(*(uint8_t*)0x200001e4 = 9);
  NONFAILING(*(uint8_t*)0x200001e5 = 5);
  NONFAILING(*(uint8_t*)0x200001e6 = 0x85);
  NONFAILING(*(uint8_t*)0x200001e7 = 0xb);
  NONFAILING(*(uint16_t*)0x200001e8 = 8);
  NONFAILING(*(uint8_t*)0x200001ea = 0);
  NONFAILING(*(uint8_t*)0x200001eb = 0);
  NONFAILING(*(uint8_t*)0x200001ec = 0);
  res = syz_usb_connect(0, 0x2d, 0x200001c0, 0);
  if (res != -1)
    r[0] = res;
  syz_usb_ep_write(r[0], 0x1c, 0, 0);
  NONFAILING(memcpy((void*)0x20002c40, "X", 1));
  syz_usb_ep_write(r[0], 0, 1, 0x20002c40);
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  setup_binfmt_misc();
  install_segv_handler();
  for (procid = 0; procid < 6; procid++) {
    if (fork() == 0) {
      use_temporary_dir();
      do_sandbox_none();
    }
  }
  sleep(1000000);
  return 0;
}