gistfile1.txt

// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.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;
}

static int inject_fault(int nth)
{
  int fd;
  char buf[16];

  fd = open("/proc/thread-self/fail-nth", O_RDWR);
  if (fd == -1)
    exit(printf("failed to open /proc/thread-self/fail-nth\n"));
  sprintf(buf, "%d", nth + 1);
  if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
    exit(printf("failed to write /proc/thread-self/fail-nth\n"));
  return fd;
}

void execute_one()
{
  int fd = syscall(__NR_socket, 0x26, 5, 0);
  *(uint16_t*)0x20000040 = 0x26;
  memcpy((void*)0x20000042,
         "\x72\x6e\x67\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 14);
  *(uint32_t*)0x20000050 = 0;
  *(uint32_t*)0x20000054 = 0;
  memcpy((void*)0x20000058,
         "\x64\x72\x62\x67\x5f\x70\x72\x5f\x63\x74\x72\x5f\x61\x65\x73\x31\x32"
         "\x38\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
         64);
  syscall(__NR_bind, fd, 0x20000040, 0x58);
  inject_fault(8);
  syscall(__NR_setsockopt, fd, 0x117, 1, 0x205b1fd0, 0);
}

int main()
{
  write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N");
  write_file("/sys/kernel/debug/fail_futex/ignore-private", "N");
  mmap((void*)0x20000000, 0x1000000, 3, 0x32, -1, 0);
  int i;
  for (i = 0; i < 8; i++) {
    if (fork() == 0) {
      for (;;) {
        int pid = fork();
        if (pid == 0) {
          execute_one();
          exit(0);
        }
        int status;
        while (waitpid(pid, &status, __WALL) != pid) {}
      }
    }
  }
  sleep(1000000);
  return 0;
}