syzkaller-repros/linux/c82773a3bdc9c1074543b9da0e865b945a3e9ef0.c

// BUG: unable to handle kernel NULL pointer dereference in __crypto_alg_lookup
// https://syzkaller.appspot.com/bug?id=c82773a3bdc9c1074543b9da0e865b945a3e9ef0
// status:dup
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE

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

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

#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

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

static void fail(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((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus);
}

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 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 use_temporary_dir()
{
  char tmpdir_template[] = "./syzkaller.XXXXXX";
  char* tmpdir = mkdtemp(tmpdir_template);
  if (!tmpdir)
    fail("failed to mkdtemp");
  if (chmod(tmpdir, 0777))
    fail("failed to chmod");
  if (chdir(tmpdir))
    fail("failed to chdir");
}

static void remove_dir(const char* dir)
{
  DIR* dp;
  struct dirent* ep;
  int iter = 0;
retry:
  dp = opendir(dir);
  if (dp == NULL) {
    if (errno == EMFILE) {
      exitf("opendir(%s) failed due to NOFILE, exiting");
    }
    exitf("opendir(%s) failed", dir);
  }
  while ((ep = readdir(dp))) {
    if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0)
      continue;
    char filename[FILENAME_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
    struct stat st;
    if (lstat(filename, &st))
      exitf("lstat(%s) failed", filename);
    if (S_ISDIR(st.st_mode)) {
      remove_dir(filename);
      continue;
    }
    int i;
    for (i = 0;; i++) {
      if (unlink(filename) == 0)
        break;
      if (errno == EROFS) {
        break;
      }
      if (errno != EBUSY || i > 100)
        exitf("unlink(%s) failed", filename);
      if (umount2(filename, MNT_DETACH))
        exitf("umount(%s) failed", filename);
    }
  }
  closedir(dp);
  int i;
  for (i = 0;; i++) {
    if (rmdir(dir) == 0)
      break;
    if (i < 100) {
      if (errno == EROFS) {
        break;
      }
      if (errno == EBUSY) {
        if (umount2(dir, MNT_DETACH))
          exitf("umount(%s) failed", dir);
        continue;
      }
      if (errno == ENOTEMPTY) {
        if (iter < 100) {
          iter++;
          goto retry;
        }
      }
    }
    exitf("rmdir(%s) failed", dir);
  }
}

static void test();

void loop()
{
  int iter;
  for (iter = 0;; iter++) {
    char cwdbuf[256];
    sprintf(cwdbuf, "./%d", iter);
    if (mkdir(cwdbuf, 0777))
      fail("failed to mkdir");
    int pid = fork();
    if (pid < 0)
      fail("loop fork failed");
    if (pid == 0) {
      prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
      setpgrp();
      if (chdir(cwdbuf))
        fail("failed to chdir");
      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;
      }
    }
    remove_dir(cwdbuf);
  }
}

long r[2];
void test()
{
  memset(r, -1, sizeof(r));
  syscall(__NR_mmap, 0x20000000ul, 0xfff000ul, 0x3ul, 0x32ul,
          0xfffffffffffffffful, 0x0ul);
  r[0] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul);
  *(uint16_t*)0x20b5efa8 = (uint16_t)0x26;
  memcpy((void*)0x20b5efaa,
         "\x61\x65\x61\x64\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
         14);
  *(uint32_t*)0x20b5efb8 = (uint32_t)0x0;
  *(uint32_t*)0x20b5efbc = (uint32_t)0x0;
  memcpy((void*)0x20b5efc0,
         "\x70\x63\x72\x79\x70\x74\x28\x73\x65\x71\x69\x76\x28\x70\x63"
         "\x72\x79\x70\x74\x28\x67\x63\x6d\x28\x61\x65\x73\x29\x29\x29"
         "\x29\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, r[0], 0x20b5efa8ul, 0x58ul);
  r[1] = syscall(__NR_socket, 0x26ul, 0x5ul, 0x0ul);
  *(uint16_t*)0x20269000 = (uint16_t)0x26;
  memcpy((void*)0x20269002,
         "\x61\x65\x61\x64\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
         14);
  *(uint32_t*)0x20269010 = (uint32_t)0x0;
  *(uint32_t*)0x20269014 = (uint32_t)0x0;
  memcpy((void*)0x20269018,
         "\x70\x63\x72\x79\x70\x74\x28\x67\x63\x6d\x5f\x62\x61\x73\x65"
         "\x28\x63\x74\x72\x28\x61\x65\x73\x2d\x61\x65\x73\x6e\x69\x29"
         "\x2c\x67\x68\x61\x73\x68\x2d\x67\x65\x6e\x65\x72\x69\x63\x29"
         "\x29\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
         "\x00\x00\x00\x00",
         64);
  syscall(__NR_bind, r[1], 0x20269000ul, 0x58ul);
}

int main()
{
  int i;
  for (i = 0; i < 8; i++) {
    if (fork() == 0) {
      use_temporary_dir();
      loop();
      return 0;
    }
  }
  sleep(1000000);
  return 0;
}