syzkaller-repros/linux/3538ce3ca74d05a57977b74ac6fd5edb1e96f378.c

// BUG: unable to handle kernel NULL pointer dereference in __list_del_entry_valid
// https://syzkaller.appspot.com/bug?id=3538ce3ca74d05a57977b74ac6fd5edb1e96f378
// status:dup
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <unistd.h>

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

#include <stdint.h>
#include <string.h>

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

static void exitf(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(kRetryStatus);
}

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

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

void loop()
{
  syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
          0xfffffffffffffffful, 0x0ul);
  *(uint32_t*)0x2001d000 = (uint32_t)0x2;
  *(uint32_t*)0x2001d004 = (uint32_t)0x78;
  *(uint8_t*)0x2001d008 = (uint8_t)0xe3;
  *(uint8_t*)0x2001d009 = (uint8_t)0x0;
  *(uint8_t*)0x2001d00a = (uint8_t)0x0;
  *(uint8_t*)0x2001d00b = (uint8_t)0x0;
  *(uint32_t*)0x2001d00c = (uint32_t)0x0;
  *(uint64_t*)0x2001d010 = (uint64_t)0x0;
  *(uint64_t*)0x2001d018 = (uint64_t)0x0;
  *(uint64_t*)0x2001d020 = (uint64_t)0x0;
  *(uint8_t*)0x2001d028 = (uint8_t)0x80000040fe;
  *(uint8_t*)0x2001d029 = (uint8_t)0x0;
  *(uint8_t*)0x2001d02a = (uint8_t)0x0;
  *(uint8_t*)0x2001d02b = (uint8_t)0x0;
  *(uint32_t*)0x2001d02c = (uint32_t)0x0;
  *(uint32_t*)0x2001d030 = (uint32_t)0x0;
  *(uint32_t*)0x2001d034 = (uint32_t)0x0;
  *(uint64_t*)0x2001d038 = (uint64_t)0x0;
  *(uint64_t*)0x2001d040 = (uint64_t)0x0;
  *(uint64_t*)0x2001d048 = (uint64_t)0x0;
  *(uint64_t*)0x2001d050 = (uint64_t)0x0;
  *(uint64_t*)0x2001d058 = (uint64_t)0x0;
  *(uint32_t*)0x2001d060 = (uint32_t)0x0;
  *(uint64_t*)0x2001d068 = (uint64_t)0x0;
  *(uint32_t*)0x2001d070 = (uint32_t)0x0;
  *(uint16_t*)0x2001d074 = (uint16_t)0x0;
  *(uint16_t*)0x2001d076 = (uint16_t)0x0;
  syscall(__NR_perf_event_open, 0x2001d000ul, 0x0ul, 0x0ul,
          0xfffffffffffffffful, 0x0ul);
  memcpy((void*)0x20f84000, "./file0", 8);
  syscall(__NR_creat, 0x20f84000ul, 0x0ul);
  memcpy((void*)0x206eaff8, "./file0", 8);
  memcpy((void*)0x206c6000, "./file0", 8);
  memcpy((void*)0x209aaffa, "tmpfs", 6);
  write_file("/sys/kernel/debug/failslab/ignore-gfp-wait", "N");
  write_file("/sys/kernel/debug/fail_futex/ignore-private", "N");
  inject_fault(13);
  syscall(__NR_mount, 0x206eaff8ul, 0x206c6000ul, 0x209aaffaul,
          0x200002ul, 0x20be9f95ul);
}

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