// https://syzkaller.appspot.com/bug?id=5a1deffc3010498854333ccdb875ae0da0d5c2a6
// 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 <net/if_arp.h>
#include <netinet/in.h>
#include <pthread.h>
#include <sched.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.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/swap.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/falloc.h>
#include <linux/futex.h>
#include <linux/genetlink.h>
#include <linux/if_addr.h>
#include <linux/if_ether.h>
#include <linux/if_link.h>
#include <linux/if_tun.h>
#include <linux/in6.h>
#include <linux/ip.h>
#include <linux/neighbour.h>
#include <linux/net.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/tcp.h>
#include <linux/veth.h>

#ifndef __NR_bpf
#define __NR_bpf 321
#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 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 void thread_start(void* (*fn)(void*), void* arg)
{
  pthread_t th;
  pthread_attr_t attr;
  pthread_attr_init(&attr);
  pthread_attr_setstacksize(&attr, 128 << 10);
  int i = 0;
  for (; i < 100; i++) {
    if (pthread_create(&th, &attr, fn, arg) == 0) {
      pthread_attr_destroy(&attr);
      return;
    }
    if (errno == EAGAIN) {
      usleep(50);
      continue;
    }
    break;
  }
  exit(1);
}

#define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off))
#define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len)               \
  *(type*)(addr) =                                                             \
      htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) |           \
            (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len))))

typedef struct {
  int state;
} event_t;

static void event_init(event_t* ev)
{
  ev->state = 0;
}

static void event_reset(event_t* ev)
{
  ev->state = 0;
}

static void event_set(event_t* ev)
{
  if (ev->state)
    exit(1);
  __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE);
  syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000);
}

static void event_wait(event_t* ev)
{
  while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0);
}

static int event_isset(event_t* ev)
{
  return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE);
}

static int event_timedwait(event_t* ev, uint64_t timeout)
{
  uint64_t start = current_time_ms();
  uint64_t now = start;
  for (;;) {
    uint64_t remain = timeout - (now - start);
    struct timespec ts;
    ts.tv_sec = remain / 1000;
    ts.tv_nsec = (remain % 1000) * 1000 * 1000;
    syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts);
    if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE))
      return 1;
    now = current_time_ms();
    if (now - start > timeout)
      return 0;
  }
}

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_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_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 int netlink_add_addr(struct nlmsg* nlmsg, int sock, const char* dev,
                            const void* addr, int addrsize)
{
  struct ifaddrmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ifa_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ifa_prefixlen = addrsize == 4 ? 24 : 120;
  hdr.ifa_scope = RT_SCOPE_UNIVERSE;
  hdr.ifa_index = if_nametoindex(dev);
  netlink_init(nlmsg, RTM_NEWADDR, NLM_F_CREATE | NLM_F_REPLACE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, IFA_LOCAL, addr, addrsize);
  netlink_attr(nlmsg, IFA_ADDRESS, addr, addrsize);
  return netlink_send(nlmsg, sock);
}

static void netlink_add_addr4(struct nlmsg* nlmsg, int sock, const char* dev,
                              const char* addr)
{
  struct in_addr in_addr;
  inet_pton(AF_INET, addr, &in_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in_addr, sizeof(in_addr));
  if (err < 0) {
  }
}

static void netlink_add_addr6(struct nlmsg* nlmsg, int sock, const char* dev,
                              const char* addr)
{
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, addr, &in6_addr);
  int err = netlink_add_addr(nlmsg, sock, dev, &in6_addr, sizeof(in6_addr));
  if (err < 0) {
  }
}

static void netlink_add_neigh(struct nlmsg* nlmsg, int sock, const char* name,
                              const void* addr, int addrsize, const void* mac,
                              int macsize)
{
  struct ndmsg hdr;
  memset(&hdr, 0, sizeof(hdr));
  hdr.ndm_family = addrsize == 4 ? AF_INET : AF_INET6;
  hdr.ndm_ifindex = if_nametoindex(name);
  hdr.ndm_state = NUD_PERMANENT;
  netlink_init(nlmsg, RTM_NEWNEIGH, NLM_F_EXCL | NLM_F_CREATE, &hdr,
               sizeof(hdr));
  netlink_attr(nlmsg, NDA_DST, addr, addrsize);
  netlink_attr(nlmsg, NDA_LLADDR, mac, macsize);
  int err = netlink_send(nlmsg, sock);
  if (err < 0) {
  }
}

static struct nlmsg nlmsg;

static int tunfd = -1;

#define TUN_IFACE "syz_tun"
#define LOCAL_MAC 0xaaaaaaaaaaaa
#define REMOTE_MAC 0xaaaaaaaaaabb
#define LOCAL_IPV4 "172.20.20.170"
#define REMOTE_IPV4 "172.20.20.187"
#define LOCAL_IPV6 "fe80::aa"
#define REMOTE_IPV6 "fe80::bb"

#define IFF_NAPI 0x0010

static void initialize_tun(void)
{
  tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
  if (tunfd == -1) {
    printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n");
    printf("otherwise fuzzing or reproducing might not work as intended\n");
    return;
  }
  const int kTunFd = 200;
  if (dup2(tunfd, kTunFd) < 0)
    exit(1);
  close(tunfd);
  tunfd = kTunFd;
  struct ifreq ifr;
  memset(&ifr, 0, sizeof(ifr));
  strncpy(ifr.ifr_name, TUN_IFACE, IFNAMSIZ);
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) {
    exit(1);
  }
  char sysctl[64];
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/accept_dad", TUN_IFACE);
  write_file(sysctl, "0");
  sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/router_solicitations", TUN_IFACE);
  write_file(sysctl, "0");
  int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if (sock == -1)
    exit(1);
  netlink_add_addr4(&nlmsg, sock, TUN_IFACE, LOCAL_IPV4);
  netlink_add_addr6(&nlmsg, sock, TUN_IFACE, LOCAL_IPV6);
  uint64_t macaddr = REMOTE_MAC;
  struct in_addr in_addr;
  inet_pton(AF_INET, REMOTE_IPV4, &in_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in_addr, sizeof(in_addr),
                    &macaddr, ETH_ALEN);
  struct in6_addr in6_addr;
  inet_pton(AF_INET6, REMOTE_IPV6, &in6_addr);
  netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in6_addr, sizeof(in6_addr),
                    &macaddr, ETH_ALEN);
  macaddr = LOCAL_MAC;
  netlink_device_change(&nlmsg, sock, TUN_IFACE, true, 0, &macaddr, ETH_ALEN,
                        NULL);
  close(sock);
}

static int runcmdline(char* cmdline)
{
  int ret = system(cmdline);
  if (ret) {
  }
  return ret;
}

static int read_tun(char* data, int size)
{
  if (tunfd < 0)
    return -1;
  int rv = read(tunfd, data, size);
  if (rv < 0) {
    if (errno == EAGAIN || errno == EBADFD)
      return -1;
    exit(1);
  }
  return rv;
}

static void flush_tun()
{
  char data[1000];
  while (read_tun(&data[0], sizeof(data)) != -1) {
  }
}

#define MAX_FDS 30

static void mount_cgroups(const char* dir, const char** controllers, int count)
{
  if (mkdir(dir, 0777)) {
    return;
  }
  char enabled[128] = {0};
  int i = 0;
  for (; i < count; i++) {
    if (mount("none", dir, "cgroup", 0, controllers[i])) {
      continue;
    }
    umount(dir);
    strcat(enabled, ",");
    strcat(enabled, controllers[i]);
  }
  if (enabled[0] == 0) {
    if (rmdir(dir) && errno != EBUSY)
      exit(1);
    return;
  }
  if (mount("none", dir, "cgroup", 0, enabled + 1)) {
    if (rmdir(dir) && errno != EBUSY)
      exit(1);
  }
  if (chmod(dir, 0777)) {
  }
}

static void mount_cgroups2(const char** controllers, int count)
{
  if (mkdir("/syzcgroup/unified", 0777)) {
    return;
  }
  if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) {
    if (rmdir("/syzcgroup/unified") && errno != EBUSY)
      exit(1);
    return;
  }
  if (chmod("/syzcgroup/unified", 0777)) {
  }
  int control = open("/syzcgroup/unified/cgroup.subtree_control", O_WRONLY);
  if (control == -1)
    return;
  int i;
  for (i = 0; i < count; i++)
    if (write(control, controllers[i], strlen(controllers[i])) < 0) {
    }
  close(control);
}

static void setup_cgroups()
{
  const char* unified_controllers[] = {"+cpu", "+io", "+pids"};
  const char* net_controllers[] = {"net", "net_prio", "devices", "blkio",
                                   "freezer"};
  const char* cpu_controllers[] = {"cpuset", "cpuacct", "hugetlb", "rlimit",
                                   "memory"};
  if (mkdir("/syzcgroup", 0777)) {
    return;
  }
  mount_cgroups2(unified_controllers,
                 sizeof(unified_controllers) / sizeof(unified_controllers[0]));
  mount_cgroups("/syzcgroup/net", net_controllers,
                sizeof(net_controllers) / sizeof(net_controllers[0]));
  mount_cgroups("/syzcgroup/cpu", cpu_controllers,
                sizeof(cpu_controllers) / sizeof(cpu_controllers[0]));
  write_file("/syzcgroup/cpu/cgroup.clone_children", "1");
  write_file("/syzcgroup/cpu/cpuset.memory_pressure_enabled", "1");
}

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/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(file, sizeof(file), "%s/memory.soft_limit_in_bytes", cgroupdir);
  write_file(file, "%d", 299 << 20);
  snprintf(file, sizeof(file), "%s/memory.limit_in_bytes", cgroupdir);
  write_file(file, "%d", 300 << 20);
  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)) {
  }
}

static void setup_binderfs()
{
  if (mkdir("/dev/binderfs", 0777)) {
  }
  if (mount("binder", "/dev/binderfs", "binder", 0, NULL)) {
  }
}

static void loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  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 = 128 << 20;
  setrlimit(RLIMIT_CORE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 256;
  setrlimit(RLIMIT_NOFILE, &rlim);
  if (unshare(CLONE_NEWNS)) {
  }
  if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) {
  }
  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);
}

static 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)) {
  }
  write_file("/proc/sys/net/ipv4/ping_group_range", "0 65535");
  initialize_tun();
  setup_binderfs();
  loop();
  exit(1);
}

#define FS_IOC_SETFLAGS _IOW('f', 2, long)
static void remove_dir(const char* dir)
{
  int iter = 0;
  DIR* dp = 0;
retry:
  while (umount2(dir, MNT_DETACH | UMOUNT_NOFOLLOW) == 0) {
  }
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exit(1);
    }
    exit(1);
  }
  struct dirent* ep = 0;
  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 | UMOUNT_NOFOLLOW) == 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 | UMOUNT_NOFOLLOW))
        exit(1);
    }
  }
  closedir(dp);
  for (int 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 | UMOUNT_NOFOLLOW))
          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);
  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 setup_loop()
{
  setup_cgroups_loop();
}

static void setup_test()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setup_cgroups_test();
  write_file("/proc/self/oom_score_adj", "1000");
  flush_tun();
  if (symlink("/dev/binderfs", "./binderfs")) {
  }
}

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

#define SWAP_FILE "./swap-file"
#define SWAP_FILE_SIZE (128 * 1000 * 1000)

static void setup_swap()
{
  swapoff(SWAP_FILE);
  unlink(SWAP_FILE);
  int fd = open(SWAP_FILE, O_CREAT | O_WRONLY | O_CLOEXEC, 0600);
  if (fd == -1) {
    exit(1);
    return;
  }
  fallocate(fd, FALLOC_FL_ZERO_RANGE, 0, SWAP_FILE_SIZE);
  close(fd);
  char cmdline[64];
  sprintf(cmdline, "mkswap %s", SWAP_FILE);
  if (runcmdline(cmdline)) {
    exit(1);
    return;
  }
  if (swapon(SWAP_FILE, SWAP_FLAG_PREFER) == 1) {
    exit(1);
    return;
  }
}

struct thread_t {
  int created, call;
  event_t ready, done;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    event_wait(&th->ready);
    event_reset(&th->ready);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    event_set(&th->done);
  }
  return 0;
}

static void execute_one(void)
{
  int i, call, thread;
  for (call = 0; call < 4; call++) {
    for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
         thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        event_init(&th->ready);
        event_init(&th->done);
        event_set(&th->done);
        thread_start(thr, th);
      }
      if (!event_isset(&th->done))
        continue;
      event_reset(&th->done);
      th->call = call;
      __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
      event_set(&th->ready);
      if (call == 2)
        break;
      event_timedwait(&th->done, 50);
      break;
    }
  }
  for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
    sleep_ms(1);
  close_fds();
}

static void execute_one(void);

#define WAIT_FLAGS __WALL

static void loop(void)
{
  setup_loop();
  int iter = 0;
  for (;; iter++) {
    char cwdbuf[32];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      exit(1);
    int pid = fork();
    if (pid < 0)
      exit(1);
    if (pid == 0) {
      if (chdir(cwdbuf))
        exit(1);
      setup_test();
      execute_one();
      exit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid)
        break;
      sleep_ms(1);
      if (current_time_ms() - start < 5000)
        continue;
      kill_and_wait(pid, &status);
      break;
    }
    remove_dir(cwdbuf);
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};

void execute_call(int call)
{
  intptr_t res = 0;
  switch (call) {
  case 0:
    NONFAILING(*(uint32_t*)0x200004c0 = 3);
    NONFAILING(*(uint32_t*)0x200004c4 = 3);
    NONFAILING(*(uint64_t*)0x200004c8 = 0x20000580);
    NONFAILING(*(uint8_t*)0x20000580 = 0x18);
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000581, 0, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000581, 0, 4, 4));
    NONFAILING(*(uint16_t*)0x20000582 = 0);
    NONFAILING(*(uint32_t*)0x20000584 = 0);
    NONFAILING(*(uint8_t*)0x20000588 = 0);
    NONFAILING(*(uint8_t*)0x20000589 = 0);
    NONFAILING(*(uint16_t*)0x2000058a = 0);
    NONFAILING(*(uint32_t*)0x2000058c = 0);
    NONFAILING(*(uint8_t*)0x20000590 = 0x95);
    NONFAILING(*(uint8_t*)0x20000591 = 0);
    NONFAILING(*(uint16_t*)0x20000592 = 0);
    NONFAILING(*(uint32_t*)0x20000594 = 0);
    NONFAILING(*(uint64_t*)0x200004d0 = 0x20000600);
    NONFAILING(memcpy((void*)0x20000600, "GPL\000", 4));
    NONFAILING(*(uint32_t*)0x200004d8 = 0);
    NONFAILING(*(uint32_t*)0x200004dc = 0);
    NONFAILING(*(uint64_t*)0x200004e0 = 0);
    NONFAILING(*(uint32_t*)0x200004e8 = 0);
    NONFAILING(*(uint32_t*)0x200004ec = 0);
    NONFAILING(memset((void*)0x200004f0, 0, 16));
    NONFAILING(*(uint32_t*)0x20000500 = 0);
    NONFAILING(*(uint32_t*)0x20000504 = 0);
    NONFAILING(*(uint32_t*)0x20000508 = 0);
    NONFAILING(*(uint32_t*)0x2000050c = 0);
    NONFAILING(*(uint64_t*)0x20000510 = 0);
    NONFAILING(*(uint32_t*)0x20000518 = 0);
    NONFAILING(*(uint32_t*)0x2000051c = 0);
    NONFAILING(*(uint64_t*)0x20000520 = 0);
    NONFAILING(*(uint32_t*)0x20000528 = 0);
    NONFAILING(*(uint32_t*)0x2000052c = 0);
    NONFAILING(*(uint32_t*)0x20000530 = 0);
    NONFAILING(*(uint32_t*)0x20000534 = 0);
    NONFAILING(*(uint64_t*)0x20000538 = 0);
    NONFAILING(*(uint64_t*)0x20000540 = 0);
    NONFAILING(*(uint32_t*)0x20000548 = 0);
    NONFAILING(*(uint32_t*)0x2000054c = 0);
    res = syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x200004c0ul, /*size=*/0x90ul);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    NONFAILING(*(uint32_t*)0x20000740 = 3);
    NONFAILING(*(uint32_t*)0x20000744 = 4);
    NONFAILING(*(uint32_t*)0x20000748 = 4);
    NONFAILING(*(uint32_t*)0x2000074c = 0xa);
    NONFAILING(*(uint32_t*)0x20000750 = 0);
    NONFAILING(*(uint32_t*)0x20000754 = 0);
    NONFAILING(*(uint32_t*)0x20000758 = 0);
    NONFAILING(memset((void*)0x2000075c, 0, 16));
    NONFAILING(*(uint32_t*)0x2000076c = 0);
    NONFAILING(*(uint32_t*)0x20000770 = 0);
    NONFAILING(*(uint32_t*)0x20000774 = 0);
    NONFAILING(*(uint32_t*)0x20000778 = 0);
    NONFAILING(*(uint32_t*)0x2000077c = 0);
    NONFAILING(*(uint64_t*)0x20000780 = 0);
    res = syscall(__NR_bpf, /*cmd=*/0ul, /*arg=*/0x20000740ul, /*size=*/0x48ul);
    if (res != -1)
      r[1] = res;
    break;
  case 2:
    NONFAILING(*(uint32_t*)0x200007c0 = r[1]);
    NONFAILING(*(uint64_t*)0x200007c8 = 0x20000800);
    NONFAILING(*(uint32_t*)0x20000800 = 0);
    NONFAILING(*(uint64_t*)0x200007d0 = 0x20000840);
    NONFAILING(*(uint32_t*)0x20000840 = r[0]);
    NONFAILING(*(uint64_t*)0x200007d8 = 0);
    syscall(__NR_bpf, /*cmd=*/2ul, /*arg=*/0x200007c0ul, /*size=*/0x1cul);
    break;
  case 3:
    NONFAILING(*(uint32_t*)0x20000880 = 3);
    NONFAILING(*(uint32_t*)0x20000884 = 8);
    NONFAILING(*(uint64_t*)0x20000888 = 0x20000940);
    NONFAILING(*(uint8_t*)0x20000940 = 0x18);
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000941, 0, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000941, 0, 4, 4));
    NONFAILING(*(uint16_t*)0x20000942 = 0);
    NONFAILING(*(uint32_t*)0x20000944 = 0);
    NONFAILING(*(uint8_t*)0x20000948 = 0);
    NONFAILING(*(uint8_t*)0x20000949 = 0);
    NONFAILING(*(uint16_t*)0x2000094a = 0);
    NONFAILING(*(uint32_t*)0x2000094c = 0);
    NONFAILING(*(uint8_t*)0x20000950 = 0x18);
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000951, 2, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000951, 1, 4, 4));
    NONFAILING(*(uint16_t*)0x20000952 = 0);
    NONFAILING(*(uint32_t*)0x20000954 = r[1]);
    NONFAILING(*(uint8_t*)0x20000958 = 0);
    NONFAILING(*(uint8_t*)0x20000959 = 0);
    NONFAILING(*(uint16_t*)0x2000095a = 0);
    NONFAILING(*(uint32_t*)0x2000095c = 0);
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000960, 7, 0, 3));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000960, 0, 3, 1));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000960, 0xb, 4, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000961, 3, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000961, 0, 4, 4));
    NONFAILING(*(uint16_t*)0x20000962 = 0);
    NONFAILING(*(uint32_t*)0x20000964 = 0);
    NONFAILING(*(uint8_t*)0x20000968 = 0x85);
    NONFAILING(*(uint8_t*)0x20000969 = 0);
    NONFAILING(*(uint16_t*)0x2000096a = 0);
    NONFAILING(*(uint32_t*)0x2000096c = 0xc);
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000970, 7, 0, 3));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000970, 0, 3, 1));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000970, 0xb, 4, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000971, 0, 0, 4));
    NONFAILING(STORE_BY_BITMASK(uint8_t, , 0x20000971, 0, 4, 4));
    NONFAILING(*(uint16_t*)0x20000972 = 0);
    NONFAILING(*(uint32_t*)0x20000974 = 0);
    NONFAILING(*(uint8_t*)0x20000978 = 0x95);
    NONFAILING(*(uint8_t*)0x20000979 = 0);
    NONFAILING(*(uint16_t*)0x2000097a = 0);
    NONFAILING(*(uint32_t*)0x2000097c = 0);
    NONFAILING(*(uint64_t*)0x20000890 = 0x20000980);
    NONFAILING(memcpy((void*)0x20000980, "GPL\000", 4));
    NONFAILING(*(uint32_t*)0x20000898 = 0);
    NONFAILING(*(uint32_t*)0x2000089c = 0);
    NONFAILING(*(uint64_t*)0x200008a0 = 0);
    NONFAILING(*(uint32_t*)0x200008a8 = 0);
    NONFAILING(*(uint32_t*)0x200008ac = 0);
    NONFAILING(memset((void*)0x200008b0, 0, 16));
    NONFAILING(*(uint32_t*)0x200008c0 = 0);
    NONFAILING(*(uint32_t*)0x200008c4 = 0);
    NONFAILING(*(uint32_t*)0x200008c8 = 0);
    NONFAILING(*(uint32_t*)0x200008cc = 0);
    NONFAILING(*(uint64_t*)0x200008d0 = 0);
    NONFAILING(*(uint32_t*)0x200008d8 = 0);
    NONFAILING(*(uint32_t*)0x200008dc = 0);
    NONFAILING(*(uint64_t*)0x200008e0 = 0);
    NONFAILING(*(uint32_t*)0x200008e8 = 0);
    NONFAILING(*(uint32_t*)0x200008ec = 0);
    NONFAILING(*(uint32_t*)0x200008f0 = 0);
    NONFAILING(*(uint32_t*)0x200008f4 = 0);
    NONFAILING(*(uint64_t*)0x200008f8 = 0);
    NONFAILING(*(uint64_t*)0x20000900 = 0);
    NONFAILING(*(uint32_t*)0x20000908 = 0);
    NONFAILING(*(uint32_t*)0x2000090c = 0);
    syscall(__NR_bpf, /*cmd=*/5ul, /*arg=*/0x20000880ul, /*size=*/0xa0ul);
    break;
  }
}
int main(void)
{
  syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul,
          /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
  syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul,
          /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
  setup_cgroups();
  setup_swap();
  install_segv_handler();
  use_temporary_dir();
  do_sandbox_none();
  return 0;
}