syzkaller-repros/linux/00b395ed1c95e10c5623e185b2e3d5912cd72f63.c

// memory leak in device_add
// https://syzkaller.appspot.com/bug?id=00b395ed1c95e10c5623e185b2e3d5912cd72f63
// status:invalid
// 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/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

static __thread int skip_segv;
static __thread jmp_buf segv_env;

static void segv_handler(int sig, siginfo_t* info, void* ctx)
{
  uintptr_t addr = (uintptr_t)info->si_addr;
  const uintptr_t prog_start = 1 << 20;
  const uintptr_t prog_end = 100 << 20;
  if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
      (addr < prog_start || addr > prog_end)) {
    _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(...)                                                        \
  {                                                                            \
    __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
    if (_setjmp(segv_env) == 0) {                                              \
      __VA_ARGS__;                                                             \
    }                                                                          \
    __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST);                       \
  }

static uint64_t current_time_ms(void)
{
  struct timespec ts;
  if (clock_gettime(CLOCK_MONOTONIC, &ts))
    exit(1);
  return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000;
}

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 int inject_fault(int nth)
{
  int fd;
  fd = open("/proc/thread-self/fail-nth", O_RDWR);
  if (fd == -1)
    exit(1);
  char buf[16];
  sprintf(buf, "%d", nth + 1);
  if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf))
    exit(1);
  return fd;
}

static void setup_fault()
{
  static struct {
    const char* file;
    const char* val;
    bool fatal;
  } files[] = {
      {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true},
      {"/sys/kernel/debug/fail_futex/ignore-private", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false},
      {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false},
  };
  unsigned i;
  for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) {
    if (!write_file(files[i].file, files[i].val)) {
      if (files[i].fatal)
        exit(1);
    }
  }
}

#define KMEMLEAK_FILE "/sys/kernel/debug/kmemleak"

static void setup_leak()
{
  if (!write_file(KMEMLEAK_FILE, "scan"))
    exit(1);
  sleep(5);
  if (!write_file(KMEMLEAK_FILE, "scan"))
    exit(1);
  if (!write_file(KMEMLEAK_FILE, "clear"))
    exit(1);
}

static void check_leaks(void)
{
  int fd = open(KMEMLEAK_FILE, O_RDWR);
  if (fd == -1)
    exit(1);
  uint64_t start = current_time_ms();
  if (write(fd, "scan", 4) != 4)
    exit(1);
  sleep(1);
  while (current_time_ms() - start < 4 * 1000)
    sleep(1);
  if (write(fd, "scan", 4) != 4)
    exit(1);
  static char buf[128 << 10];
  ssize_t n = read(fd, buf, sizeof(buf) - 1);
  if (n < 0)
    exit(1);
  int nleaks = 0;
  if (n != 0) {
    sleep(1);
    if (write(fd, "scan", 4) != 4)
      exit(1);
    if (lseek(fd, 0, SEEK_SET) < 0)
      exit(1);
    n = read(fd, buf, sizeof(buf) - 1);
    if (n < 0)
      exit(1);
    buf[n] = 0;
    char* pos = buf;
    char* end = buf + n;
    while (pos < end) {
      char* next = strstr(pos + 1, "unreferenced object");
      if (!next)
        next = end;
      char prev = *next;
      *next = 0;
      fprintf(stderr, "BUG: memory leak\n%s\n", pos);
      *next = prev;
      pos = next;
      nleaks++;
    }
  }
  if (write(fd, "clear", 5) != 5)
    exit(1);
  close(fd);
  if (nleaks)
    exit(1);
}

uint64_t r[1] = {0xffffffffffffffff};

int main(void)
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  setup_leak();
  setup_fault();
  install_segv_handler();
  use_temporary_dir();
  intptr_t res = 0;
  res = syscall(__NR_socket, 0x10, 3, 0);
  if (res != -1)
    r[0] = res;
  syscall(__NR_socketpair, 1, 2, 0, 0);
  syscall(__NR_ioctl, -1, 0x8912, 0x400200);
  NONFAILING(*(uint64_t*)0x20000580 = 0);
  NONFAILING(*(uint32_t*)0x20000588 = 0xc8);
  NONFAILING(*(uint64_t*)0x20000590 = 0x20000000);
  NONFAILING(*(uint64_t*)0x20000000 = 0x20000140);
  NONFAILING(*(uint32_t*)0x20000140 = 0x50);
  NONFAILING(*(uint16_t*)0x20000144 = 0x10);
  NONFAILING(*(uint16_t*)0x20000146 = 0x705);
  NONFAILING(*(uint32_t*)0x20000148 = 0);
  NONFAILING(*(uint32_t*)0x2000014c = 0);
  NONFAILING(*(uint8_t*)0x20000150 = 0);
  NONFAILING(*(uint8_t*)0x20000151 = 0);
  NONFAILING(*(uint16_t*)0x20000152 = 0);
  NONFAILING(*(uint32_t*)0x20000154 = 0);
  NONFAILING(*(uint32_t*)0x20000158 = 0);
  NONFAILING(*(uint32_t*)0x2000015c = 0);
  NONFAILING(*(uint16_t*)0x20000160 = 8);
  NONFAILING(*(uint16_t*)0x20000162 = 0xd);
  NONFAILING(*(uint8_t*)0x20000164 = 0);
  NONFAILING(*(uint16_t*)0x20000168 = 0x28);
  NONFAILING(*(uint16_t*)0x2000016a = 0x12);
  NONFAILING(*(uint16_t*)0x2000016c = 0xc);
  NONFAILING(*(uint16_t*)0x2000016e = 1);
  NONFAILING(memcpy((void*)0x20000170, "veth\000", 5));
  NONFAILING(*(uint16_t*)0x20000178 = 0x18);
  NONFAILING(*(uint16_t*)0x2000017a = 2);
  NONFAILING(*(uint16_t*)0x2000017c = 0x14);
  NONFAILING(*(uint16_t*)0x2000017e = 1);
  NONFAILING(*(uint8_t*)0x20000180 = 0);
  NONFAILING(*(uint8_t*)0x20000181 = 0);
  NONFAILING(*(uint16_t*)0x20000182 = 0);
  NONFAILING(*(uint32_t*)0x20000184 = 0);
  NONFAILING(*(uint32_t*)0x20000188 = 0);
  NONFAILING(*(uint32_t*)0x2000018c = 0);
  NONFAILING(*(uint64_t*)0x20000008 = 0x50);
  NONFAILING(*(uint64_t*)0x20000598 = 1);
  NONFAILING(*(uint64_t*)0x200005a0 = 0);
  NONFAILING(*(uint64_t*)0x200005a8 = 0);
  NONFAILING(*(uint32_t*)0x200005b0 = 0);
  inject_fault(92);
  syscall(__NR_sendmsg, r[0], 0x20000580, 0);
  check_leaks();
  return 0;
}