syzkaller-repros/linux/38d8778225e33561d93e68e045a89cd322683ddd.c

// kernel panic: Attempted to kill init!
// https://syzkaller.appspot.com/bug?id=38d8778225e33561d93e68e045a89cd322683ddd
// status:invalid
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <errno.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>

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

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

__attribute__((noreturn)) static void fail(const char* msg, ...)
{
  int e = errno;
  fflush(stdout);
  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);
}

__attribute__((noreturn)) static void exitf(const char* msg, ...)
{
  int e = errno;
  fflush(stdout);
  va_list args;
  va_start(args, msg);
  vfprintf(stderr, msg, args);
  va_end(args);
  fprintf(stderr, " (errno %d)\n", e);
  doexit(kRetryStatus);
}

static uint64_t current_time_ms()
{
  struct timespec ts;

  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    fail("clock_gettime failed");
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

static void test();

void loop()
{
  int iter;
  for (iter = 0;; iter++) {
    int pid = fork();
    if (pid < 0)
      fail("clone failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      test();
      doexit(0);
    }
    int status = 0;
    uint64_t start = current_time_ms();
    for (;;) {
      int res = waitpid(-1, &status, __WALL | WNOHANG);
      if (res == pid)
        break;
      usleep(1000);
      if (current_time_ms() - start > 5 * 1000) {
        kill(-pid, SIGKILL);
        kill(pid, SIGKILL);
        while (waitpid(-1, &status, __WALL) != pid) {
        }
        break;
      }
    }
  }
}

long r[9];
void test()
{
  memset(r, -1, sizeof(r));
  r[0] = syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
                 0xfffffffffffffffful, 0x0ul);
  r[1] = syscall(__NR_inotify_init1, 0x0ul);
  *(uint32_t*)0x20afa000 = (uint32_t)0xc;
  r[3] = syscall(__NR_getsockopt, 0xfffffffffffffffful, 0x1ul, 0x11ul,
                 0x20962000ul, 0x20afa000ul);
  if (r[3] != -1)
    r[4] = *(uint32_t*)0x20962000;
  r[5] = syscall(__NR_fcntl, r[1], 0x8ul, r[4]);
  r[6] = syscall(__NR_fcntl, r[1], 0x10ul, 0x20c1fff8ul);
  if (r[6] != -1)
    r[7] = *(uint32_t*)0x20c1fffc;
  r[8] = syscall(__NR_ptrace, 0x4206ul, r[7], 0x0ul, 0x100020ul);
}

int main()
{
  loop();
  return 0;
}