// https://syzkaller.appspot.com/bug?id=4462682cd32aee8ff03a43c8b9be3963743bc506
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <errno.h>
#include <fcntl.h>
#include <fcntl.h>
#include <linux/capability.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <unistd.h>

__attribute__((noreturn)) static void doexit(int status)
{
  volatile unsigned i;
  syscall(__NR_exit_group, status);
  for (i = 0;; i++) {
  }
}

#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

const int kFailStatus = 67;
const int kRetryStatus = 69;

static void fail(const char* msg, ...)
{
  int e = errno;
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

#define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1)

#define BITMASK_LEN_OFF(type, bf_off, bf_len)                          \
  (type)(BITMASK_LEN(type, (bf_len)) << (bf_off))

#define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len)              \
  if ((bf_off) == 0 && (bf_len) == 0) {                                \
    *(type*)(addr) = (type)(val);                                      \
  } else {                                                             \
    type new_val = *(type*)(addr);                                     \
    new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len));             \
    new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off);  \
    *(type*)(addr) = new_val;                                          \
  }

struct csum_inet {
  uint32_t acc;
};

static void csum_inet_init(struct csum_inet* csum)
{
  csum->acc = 0;
}

static void csum_inet_update(struct csum_inet* csum,
                             const uint8_t* data, size_t length)
{
  if (length == 0)
    return;

  size_t i;
  for (i = 0; i < length - 1; i += 2)
    csum->acc += *(uint16_t*)&data[i];

  if (length & 1)
    csum->acc += (uint16_t)data[length - 1];

  while (csum->acc > 0xffff)
    csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16);
}

static uint16_t csum_inet_digest(struct csum_inet* csum)
{
  return ~csum->acc;
}

static void use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t 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 {
    char buf[1024];
    char* hash;
    strncpy(buf, (char*)a0, sizeof(buf));
    buf[sizeof(buf) - 1] = 0;
    while ((hash = strchr(buf, '#'))) {
      *hash = '0' + (char)(a1 % 10);
      a1 /= 10;
    }
    return open(buf, a2, 0);
  }
}

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 = 128 << 20;
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 8 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 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);

  unshare(CLONE_NEWNS);
  unshare(CLONE_NEWIPC);
  unshare(CLONE_IO);
}

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) {
    close(fd);
    return false;
  }
  close(fd);
  return true;
}

static int real_uid;
static int real_gid;
__attribute__((aligned(64 << 10))) static char sandbox_stack[1 << 20];

static int namespace_sandbox_proc(void* arg)
{
  sandbox_common();

  write_file("/proc/self/setgroups", "deny");
  if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid))
    fail("write of /proc/self/uid_map failed");
  if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid))
    fail("write of /proc/self/gid_map failed");

  if (mkdir("./syz-tmp", 0777))
    fail("mkdir(syz-tmp) failed");
  if (mount("", "./syz-tmp", "tmpfs", 0, NULL))
    fail("mount(tmpfs) failed");
  if (mkdir("./syz-tmp/newroot", 0777))
    fail("mkdir failed");
  if (mkdir("./syz-tmp/newroot/dev", 0700))
    fail("mkdir failed");
  if (mount("/dev", "./syz-tmp/newroot/dev", NULL,
            MS_BIND | MS_REC | MS_PRIVATE, NULL))
    fail("mount(dev) failed");
  if (mkdir("./syz-tmp/newroot/proc", 0700))
    fail("mkdir failed");
  if (mount(NULL, "./syz-tmp/newroot/proc", "proc", 0, NULL))
    fail("mount(proc) failed");
  if (mkdir("./syz-tmp/pivot", 0777))
    fail("mkdir failed");
  if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) {
    if (chdir("./syz-tmp"))
      fail("chdir failed");
  } else {
    if (chdir("/"))
      fail("chdir failed");
    if (umount2("./pivot", MNT_DETACH))
      fail("umount failed");
  }
  if (chroot("./newroot"))
    fail("chroot failed");
  if (chdir("/"))
    fail("chdir failed");

  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))
    fail("capget failed");
  cap_data[0].effective &= ~(1 << CAP_SYS_PTRACE);
  cap_data[0].permitted &= ~(1 << CAP_SYS_PTRACE);
  cap_data[0].inheritable &= ~(1 << CAP_SYS_PTRACE);
  if (syscall(SYS_capset, &cap_hdr, &cap_data))
    fail("capset failed");

  loop();
  doexit(1);
}

static int do_sandbox_namespace(int executor_pid, bool enable_tun)
{

  real_uid = getuid();
  real_gid = getgid();
  mprotect(sandbox_stack, 4096, PROT_NONE);
  return clone(
      namespace_sandbox_proc,
      &sandbox_stack[sizeof(sandbox_stack) - 64],
      CLONE_NEWUSER | CLONE_NEWPID | CLONE_NEWUTS | CLONE_NEWNET, NULL);
}

long r[94];
void* thr(void* arg)
{
  switch ((long)arg) {
  case 0:
    r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
                   0xfffffffffffffffful, 0x0ul);
    break;
  case 1:
    memcpy((void*)0x2002a000, "\x2f\x64\x65\x76\x2f\x73\x67\x23\x00",
           9);
    r[2] = syz_open_dev(0x2002a000ul, 0x0ul, 0x142ul);
    break;
  case 2:
    *(uint8_t*)0x205c3000 = (uint8_t)0x0;
    *(uint8_t*)0x205c3001 = (uint8_t)0x0;
    *(uint16_t*)0x205c3002 = (uint16_t)0x0;
    *(uint16_t*)0x205c3004 = (uint16_t)0x0;
    *(uint16_t*)0x205c3006 = (uint16_t)0x2;
    *(uint16_t*)0x205c3008 = (uint16_t)0x0;
    STORE_BY_BITMASK(uint8_t, 0x205c300a, 0x0, 0, 4);
    STORE_BY_BITMASK(uint8_t, 0x205c300a, 0x6, 4, 4);
    memcpy((void*)0x205c300b, "\xde\x57\x29", 3);
    *(uint16_t*)0x205c300e = (uint16_t)0x6000;
    *(uint8_t*)0x205c3010 = (uint8_t)0x0;
    *(uint8_t*)0x205c3011 = (uint8_t)0x0;
    *(uint8_t*)0x205c3012 = (uint8_t)0xfe;
    *(uint8_t*)0x205c3013 = (uint8_t)0x80;
    *(uint8_t*)0x205c3014 = (uint8_t)0x0;
    *(uint8_t*)0x205c3015 = (uint8_t)0x0;
    *(uint8_t*)0x205c3016 = (uint8_t)0x0;
    *(uint8_t*)0x205c3017 = (uint8_t)0x0;
    *(uint8_t*)0x205c3018 = (uint8_t)0x0;
    *(uint8_t*)0x205c3019 = (uint8_t)0x0;
    *(uint8_t*)0x205c301a = (uint8_t)0x0;
    *(uint8_t*)0x205c301b = (uint8_t)0x0;
    *(uint8_t*)0x205c301c = (uint8_t)0x0;
    *(uint8_t*)0x205c301d = (uint8_t)0x0;
    *(uint8_t*)0x205c301e = (uint8_t)0x0;
    *(uint8_t*)0x205c301f = (uint8_t)0x0;
    *(uint8_t*)0x205c3020 = (uint8_t)0x0;
    *(uint8_t*)0x205c3021 = (uint8_t)0xbb;
    *(uint8_t*)0x205c3022 = (uint8_t)0xfe;
    *(uint8_t*)0x205c3023 = (uint8_t)0x80;
    *(uint8_t*)0x205c3024 = (uint8_t)0x0;
    *(uint8_t*)0x205c3025 = (uint8_t)0x0;
    *(uint8_t*)0x205c3026 = (uint8_t)0x0;
    *(uint8_t*)0x205c3027 = (uint8_t)0x0;
    *(uint8_t*)0x205c3028 = (uint8_t)0x0;
    *(uint8_t*)0x205c3029 = (uint8_t)0x0;
    *(uint8_t*)0x205c302a = (uint8_t)0x0;
    *(uint8_t*)0x205c302b = (uint8_t)0x0;
    *(uint8_t*)0x205c302c = (uint8_t)0x0;
    *(uint8_t*)0x205c302d = (uint8_t)0x0;
    *(uint8_t*)0x205c302e = (uint8_t)0x0;
    *(uint8_t*)0x205c302f = (uint8_t)0x0;
    *(uint8_t*)0x205c3030 = (uint8_t)0x0;
    *(uint8_t*)0x205c3031 = (uint8_t)0xaa;
    *(uint8_t*)0x205c3032 = (uint8_t)0x0;
    *(uint8_t*)0x205c3033 = (uint8_t)0x0;
    *(uint8_t*)0x205c3034 = (uint8_t)0x0;
    *(uint8_t*)0x205c3035 = (uint8_t)0x0;
    *(uint8_t*)0x205c3036 = (uint8_t)0x0;
    *(uint8_t*)0x205c3037 = (uint8_t)0x0;
    *(uint8_t*)0x205c3038 = (uint8_t)0x0;
    *(uint8_t*)0x205c3039 = (uint8_t)0x0;
    *(uint16_t*)0x205c303a = (uint16_t)0x204e;
    *(uint16_t*)0x205c303c = (uint16_t)0x214e;
    *(uint32_t*)0x205c303e = (uint32_t)0x42424242;
    *(uint32_t*)0x205c3042 = (uint32_t)0x42424242;
    STORE_BY_BITMASK(uint8_t, 0x205c3046, 0x0, 0, 1);
    STORE_BY_BITMASK(uint8_t, 0x205c3046, 0x0, 1, 3);
    STORE_BY_BITMASK(uint8_t, 0x205c3046, 0x16, 4, 4);
    *(uint8_t*)0x205c3047 = (uint8_t)0x0;
    *(uint16_t*)0x205c3048 = (uint16_t)0x0;
    *(uint16_t*)0x205c304a = (uint16_t)0x0;
    *(uint16_t*)0x205c304c = (uint16_t)0x0;
    *(uint8_t*)0x205c304e = (uint8_t)0x5;
    *(uint8_t*)0x205c304f = (uint8_t)0x26;
    *(uint32_t*)0x205c3050 = (uint32_t)0x80000;
    *(uint32_t*)0x205c3054 = (uint32_t)0x9000000;
    *(uint32_t*)0x205c3058 = (uint32_t)0x1000000;
    *(uint32_t*)0x205c305c = (uint32_t)0x1f000000;
    *(uint32_t*)0x205c3060 = (uint32_t)0x41000000;
    *(uint32_t*)0x205c3064 = (uint32_t)0x5000000;
    *(uint32_t*)0x205c3068 = (uint32_t)0x1000100;
    *(uint32_t*)0x205c306c = (uint32_t)0x4000000;
    *(uint32_t*)0x205c3070 = (uint32_t)0x1010000;
    *(uint8_t*)0x205c3074 = (uint8_t)0x2;
    *(uint8_t*)0x205c3075 = (uint8_t)0x4;
    *(uint16_t*)0x205c3076 = (uint16_t)0xac1;
    *(uint8_t*)0x205c3078 = (uint8_t)0xfe;
    *(uint8_t*)0x205c3079 = (uint8_t)0x2;
    *(uint8_t*)0x205c307a = (uint8_t)0x0;
    *(uint8_t*)0x205c307b = (uint8_t)0x13;
    *(uint8_t*)0x205c307c = (uint8_t)0x12;
    memcpy((void*)0x205c307d, "\x40\x08\x07\xe3\xee\xe9\xb1\x73\xb4\x08"
                              "\x11\x5e\xf4\x5c\x5e\x18",
           16);
    *(uint8_t*)0x205c308d = (uint8_t)0x3;
    *(uint8_t*)0x205c308e = (uint8_t)0x3;
    *(uint8_t*)0x205c308f = (uint8_t)0x6;
    struct csum_inet csum_89;
    csum_inet_init(&csum_89);
    csum_inet_update(&csum_89, (const uint8_t*)0x205c3012, 16);
    csum_inet_update(&csum_89, (const uint8_t*)0x205c3022, 16);
    uint32_t csum_89_chunk_2 = 0x58000000;
    csum_inet_update(&csum_89, (const uint8_t*)&csum_89_chunk_2, 4);
    uint32_t csum_89_chunk_3 = 0x6000000;
    csum_inet_update(&csum_89, (const uint8_t*)&csum_89_chunk_3, 4);
    csum_inet_update(&csum_89, (const uint8_t*)0x205c303a, 88);
    *(uint16_t*)0x205c304a = csum_inet_digest(&csum_89);
    r[90] = syscall(__NR_write, r[2], 0x205c3000ul, 0x92ul);
    break;
  case 3:
    *(uint64_t*)0x206e4000 = (uint64_t)0x20c7d000;
    *(uint64_t*)0x206e4008 = (uint64_t)0xb7;
    r[93] = syscall(__NR_readv, r[2], 0x206e4000ul, 0x1ul);
    break;
  }
  return 0;
}

void loop()
{
  long i;
  pthread_t th[8];

  memset(r, -1, sizeof(r));
  srand(getpid());
  for (i = 0; i < 4; i++) {
    pthread_create(&th[i], 0, thr, (void*)i);
    usleep(rand() % 10000);
  }
  for (i = 0; i < 4; i++) {
    pthread_create(&th[4 + i], 0, thr, (void*)i);
    if (rand() % 2)
      usleep(rand() % 10000);
  }
  usleep(rand() % 100000);
}

int main()
{
  use_temporary_dir();
  int pid = do_sandbox_namespace(0, false);
  int status = 0;
  while (waitpid(pid, &status, __WALL) != pid) {
  }
  return 0;
}