// https://syzkaller.appspot.com/bug?id=5bbec74cb4d7b4ae0ac1e45d4a965fdaa3413422
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <sched.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include <linux/capability.h>

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 MAX_FDS 30

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

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

uint64_t r[1] = {0xffffffffffffffff};

void loop(void)
{
  intptr_t res = 0;
  res = syscall(__NR_socket, 0x2000000000000021ul, 2ul, 2);
  if (res != -1)
    r[0] = res;
  *(uint16_t*)0x20000080 = 0x21;
  *(uint16_t*)0x20000082 = 0;
  *(uint16_t*)0x20000084 = 2;
  *(uint16_t*)0x20000086 = 0x10;
  *(uint16_t*)0x20000088 = 2;
  *(uint16_t*)0x2000008a = htobe16(0x4e21);
  *(uint8_t*)0x2000008c = 0xac;
  *(uint8_t*)0x2000008d = 0x14;
  *(uint8_t*)0x2000008e = 0x14;
  *(uint8_t*)0x2000008f = 0;
  syscall(__NR_connect, r[0], 0x20000080ul, 0x24ul);
  *(uint64_t*)0x20005c00 = 0;
  *(uint32_t*)0x20005c08 = 0;
  *(uint64_t*)0x20005c10 = 0;
  *(uint64_t*)0x20005c18 = 0;
  *(uint64_t*)0x20005c20 = 0x20000180;
  memcpy((void*)0x20000180,
         "\x18\x00\x00\x00\x00\x00\x00\x00\x10\x01\x00\x00\x01\x00\x00\x00\x77"
         "\x00\x00\x00\x00\x00\x00\x00\xdb\xee\x1f\x2b\xa6\x8d\xf5\x0d\x9d\x16"
         "\x5f\xd7\x91\x54\x9e\xa2\x94\x19\xfa\x1c\x35\xdd\x96\x99\x22\xe4\xc5"
         "\xea\xa8\x87\xd6\xf6\x5d\xd2\xf2\xbc\xf0\x36\x1d\x4c\x49\x31\xa9\x85"
         "\x72\xfe\x33\x72\x78\xdb\x2f\x70\x10\xaf\x18\x87\x85\x15\x69\x42\x75"
         "\x7d\x03\x9f\xc5\xf9\xc1\x1f\x08\x08\x66\xed\xc2\x10\xdb\xf2\xd9\x4a"
         "\xec\xdf\x80\x5d\xcc\xc4\xdf\xcb\x24\x1a\x94\x33\x86\x7e\x95\xb9\xba"
         "\x88\x00\xcf\x2c\xcc\xdd\x0e\x0a\x01\xe7\x51\xbc\xe3\x93\x61\xa2\x15"
         "\x86\x06\x88\x66\x5e\x22\x9d\xcb\x84\x18\x1b\x1d\xf8\xb9\x5c\x06\x44"
         "\x20\x05\x27\xe3\x9b\x68\x30\x2b\x1f\x40\x49\x34\x88\x58\x92\xce\xa3"
         "\x32\xba\x4e\xe3\xb9\xde\x7c\x5e\xe0\x09\xcd\x97\x15\x42\x03\x1e\xda"
         "\xa9\x39\x6b\xf4\x1b\x72\x43\xd1\xf8\xd9\x3b\x8a\x0a\x4b\xa1\xbe\x62"
         "\xba\x14\xe3\x9f\xe9\xef\x9c\x91\x5f\x01\xa9\xc4\x49\x0a",
         218);
  *(uint64_t*)0x20005c28 = 0x18;
  *(uint32_t*)0x20005c30 = 0;
  *(uint32_t*)0x20005c38 = 0;
  syscall(__NR_sendmmsg, r[0], 0x20005c00ul, 1ul, 0ul);
  close_fds();
}
int main(void)
{
  syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0);
  do_sandbox_none();
  return 0;
}