// https://syzkaller.appspot.com/bug?id=08acfb3ecee71b9442e8275dde26607f2ad7c6a1
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.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/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

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 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;
}

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)
    ;
}

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

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();
  use_temporary_dir();
  intptr_t res = 0;
  if (write(1, "executing program\n", sizeof("executing program\n") - 1)) {
  }
  //  socket$pppl2tp arguments: [
  //    domain: const = 0x18 (8 bytes)
  //    type: const = 0x1 (8 bytes)
  //    proto: const = 0x1 (4 bytes)
  //  ]
  //  returns sock_pppl2tp
  res = syscall(__NR_socket, /*domain=*/0x18ul, /*type=*/1ul, /*proto=*/1);
  if (res != -1)
    r[0] = res;
  //  socket$inet6_udp arguments: [
  //    domain: const = 0xa (8 bytes)
  //    type: const = 0x2 (8 bytes)
  //    proto: const = 0x0 (4 bytes)
  //  ]
  //  returns sock_udp6
  res = syscall(__NR_socket, /*domain=*/0xaul, /*type=*/2ul, /*proto=*/0);
  if (res != -1)
    r[1] = res;
  //  connect$pppl2tp arguments: [
  //    fd: sock_pppl2tp (resource)
  //    addr: ptr[in, sockaddr_pppl2tp] {
  //      union sockaddr_pppl2tp {
  //        pppol2tpv3: sockaddr_pppl2tp_t[pppol2tpv3_addr] {
  //          sa_family: const = 0x18 (2 bytes)
  //          sa_protocol: const = 0x1 (4 bytes)
  //          addr: pppol2tp_addr_t[int32] {
  //            pid: const = 0x3 (4 bytes)
  //            fd: sock (resource)
  //            addr: sockaddr_in {
  //              family: const = 0x2 (2 bytes)
  //              port: int16be = 0x4e23 (2 bytes)
  //              addr: union ipv4_addr {
  //                broadcast: const = 0xffffffff (4 bytes)
  //              }
  //              pad = 0x0 (8 bytes)
  //            }
  //            s_tunnel: int32 = 0x2 (4 bytes)
  //            s_session: int32 = 0x0 (4 bytes)
  //            d_tunnel: int32 = 0x4 (4 bytes)
  //            d_session: int32 = 0x0 (4 bytes)
  //          }
  //        }
  //      }
  //    }
  //    addrlen: len = 0x2e (8 bytes)
  //  ]
  NONFAILING(*(uint16_t*)0x200000000740 = 0x18);
  NONFAILING(*(uint32_t*)0x200000000742 = 1);
  NONFAILING(*(uint32_t*)0x200000000746 = 3);
  NONFAILING(*(uint32_t*)0x20000000074a = r[1]);
  NONFAILING(*(uint16_t*)0x20000000074e = 2);
  NONFAILING(*(uint16_t*)0x200000000750 = htobe16(0x4e23));
  NONFAILING(*(uint32_t*)0x200000000752 = htobe32(-1));
  NONFAILING(*(uint32_t*)0x20000000075e = 2);
  NONFAILING(*(uint32_t*)0x200000000762 = 0);
  NONFAILING(*(uint32_t*)0x200000000766 = 4);
  NONFAILING(*(uint32_t*)0x20000000076a = 0);
  syscall(__NR_connect, /*fd=*/r[0], /*addr=*/0x200000000740ul,
          /*addrlen=*/0x2eul);
  //  ioctl$PPPIOCGFLAGS arguments: [
  //    fd: sock_pppox (resource)
  //    cmd: const = 0x8004745a (4 bytes)
  //    arg: nil
  //  ]
  syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x8004745a, /*arg=*/0ul);
  return 0;
}