syzkaller-repros/linux/37eefadff13665da133828ad3344b1d2b20d7837.c

// KASAN: use-after-free Read in fib6_add_1
// https://syzkaller.appspot.com/bug?id=37eefadff13665da133828ad3344b1d2b20d7837
// status:fixed
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <errno.h>
#include <linux/futex.h>
#include <pthread.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <sys/wait.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 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 loop();

static void sandbox_common()
{
  prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
  setpgrp();
  setsid();

  struct rlimit rlim;
  rlim.rlim_cur = rlim.rlim_max = 128 << 20;
  setrlimit(RLIMIT_AS, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 8 << 20;
  setrlimit(RLIMIT_MEMLOCK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_FSIZE, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 1 << 20;
  setrlimit(RLIMIT_STACK, &rlim);
  rlim.rlim_cur = rlim.rlim_max = 0;
  setrlimit(RLIMIT_CORE, &rlim);

#define CLONE_NEWCGROUP 0x02000000

  unshare(CLONE_NEWNS);
  unshare(CLONE_NEWIPC);
  unshare(CLONE_NEWCGROUP);
  unshare(CLONE_NEWNET);
  unshare(CLONE_NEWUTS);
  unshare(CLONE_SYSVSEM);
}

static int do_sandbox_none(int executor_pid, bool enable_tun)
{
  unshare(CLONE_NEWPID);
  int pid = fork();
  if (pid < 0)
    fail("sandbox fork failed");
  if (pid)
    return pid;

  sandbox_common();

  loop();
  doexit(1);
}

static void test();

void loop()
{
  while (1) {
    test();
  }
}

struct thread_t {
  int created, running, call;
  pthread_t th;
};

static struct thread_t threads[16];
static void execute_call(int call);
static int running;

static void* thr(void* arg)
{
  struct thread_t* th = (struct thread_t*)arg;
  for (;;) {
    while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
      syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
    execute_call(th->call);
    __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
    __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
    syscall(SYS_futex, &th->running, FUTEX_WAKE);
  }
  return 0;
}

static void execute(int num_calls)
{
  int call, thread;
  running = 0;
  for (call = 0; call < num_calls; call++) {
    for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
      struct thread_t* th = &threads[thread];
      if (!th->created) {
        th->created = 1;
        pthread_attr_t attr;
        pthread_attr_init(&attr);
        pthread_attr_setstacksize(&attr, 128 << 10);
        pthread_create(&th->th, &attr, thr, th);
      }
      if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
        th->call = call;
        __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
        __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
        syscall(SYS_futex, &th->running, FUTEX_WAKE);
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

long r[5];
uint64_t procid;
void execute_call(int call)
{
  switch (call) {
  case 0:
    syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0);
    break;
  case 1:
    r[0] = syscall(__NR_socket, 2, 0x80a, 0);
    break;
  case 2:
    memcpy((void*)0x208a3fe0,
           "\x6c\x6f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x208a3ff0 = 0xfffd;
    syscall(__NR_ioctl, r[0], 0x8914, 0x208a3fe0);
    break;
  case 3:
    r[1] = syscall(__NR_socket, 0x10, 3, 0);
    break;
  case 4:
    memcpy((void*)0x208a3fe0,
           "\x6c\x6f\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint16_t*)0x208a3ff0 = 2;
    *(uint16_t*)0x208a3ff2 = 0;
    *(uint32_t*)0x208a3ff4 = htobe32(0);
    *(uint8_t*)0x208a3ff8 = 0;
    *(uint8_t*)0x208a3ff9 = 0;
    *(uint8_t*)0x208a3ffa = 0;
    *(uint8_t*)0x208a3ffb = 0;
    *(uint8_t*)0x208a3ffc = 0;
    *(uint8_t*)0x208a3ffd = 0;
    *(uint8_t*)0x208a3ffe = 0;
    *(uint8_t*)0x208a3fff = 0;
    syscall(__NR_ioctl, r[1], 0x8914, 0x208a3fe0);
    break;
  case 5:
    r[2] = syscall(__NR_socket, 0xa, 0x1000000000003, 4);
    break;
  case 6:
    memcpy((void*)0x202bf000,
           "\x73\x69\x74\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
           16);
    *(uint32_t*)0x202bf010 = 0;
    *(uint8_t*)0x202bf014 = 0;
    *(uint8_t*)0x202bf015 = 0;
    *(uint8_t*)0x202bf016 = 0;
    *(uint8_t*)0x202bf017 = 0;
    *(uint8_t*)0x202bf018 = 0;
    *(uint8_t*)0x202bf019 = 0;
    *(uint8_t*)0x202bf01a = 0;
    *(uint8_t*)0x202bf01b = 0;
    *(uint8_t*)0x202bf01c = 0;
    *(uint8_t*)0x202bf01d = 0;
    *(uint8_t*)0x202bf01e = 0;
    *(uint8_t*)0x202bf01f = 0;
    *(uint8_t*)0x202bf020 = 0;
    *(uint8_t*)0x202bf021 = 0;
    *(uint8_t*)0x202bf022 = 0;
    *(uint8_t*)0x202bf023 = 0;
    *(uint8_t*)0x202bf024 = 0;
    *(uint8_t*)0x202bf025 = 0;
    *(uint8_t*)0x202bf026 = 0;
    *(uint8_t*)0x202bf027 = 0;
    if (syscall(__NR_ioctl, r[2], 0x8933, 0x202bf000) != -1)
      r[3] = *(uint32_t*)0x202bf010;
    break;
  case 7:
    *(uint8_t*)0x20d03fb0 = 0;
    *(uint8_t*)0x20d03fb1 = 0;
    *(uint8_t*)0x20d03fb2 = 0;
    *(uint8_t*)0x20d03fb3 = 0;
    *(uint8_t*)0x20d03fb4 = 0;
    *(uint8_t*)0x20d03fb5 = 0;
    *(uint8_t*)0x20d03fb6 = 0;
    *(uint8_t*)0x20d03fb7 = 0;
    *(uint8_t*)0x20d03fb8 = 0;
    *(uint8_t*)0x20d03fb9 = 0;
    *(uint8_t*)0x20d03fba = 0;
    *(uint8_t*)0x20d03fbb = 0;
    *(uint8_t*)0x20d03fbc = 0;
    *(uint8_t*)0x20d03fbd = 0;
    *(uint8_t*)0x20d03fbe = 0;
    *(uint8_t*)0x20d03fbf = 0;
    *(uint8_t*)0x20d03fc0 = 0;
    *(uint8_t*)0x20d03fc1 = 0;
    *(uint8_t*)0x20d03fc2 = 0;
    *(uint8_t*)0x20d03fc3 = 0;
    *(uint8_t*)0x20d03fc4 = 0;
    *(uint8_t*)0x20d03fc5 = 0;
    *(uint8_t*)0x20d03fc6 = 0;
    *(uint8_t*)0x20d03fc7 = 0;
    *(uint8_t*)0x20d03fc8 = 0;
    *(uint8_t*)0x20d03fc9 = 0;
    *(uint8_t*)0x20d03fca = 0;
    *(uint8_t*)0x20d03fcb = 0;
    *(uint8_t*)0x20d03fcc = 0;
    *(uint8_t*)0x20d03fcd = 0;
    *(uint8_t*)0x20d03fce = 0;
    *(uint8_t*)0x20d03fcf = 0;
    *(uint8_t*)0x20d03fd0 = 0xfe;
    *(uint8_t*)0x20d03fd1 = 0x80;
    *(uint8_t*)0x20d03fd2 = 0;
    *(uint8_t*)0x20d03fd3 = 0;
    *(uint8_t*)0x20d03fd4 = 0;
    *(uint8_t*)0x20d03fd5 = 0;
    *(uint8_t*)0x20d03fd6 = 0;
    *(uint8_t*)0x20d03fd7 = 0;
    *(uint8_t*)0x20d03fd8 = 0;
    *(uint8_t*)0x20d03fd9 = 0;
    *(uint8_t*)0x20d03fda = 0;
    *(uint8_t*)0x20d03fdb = 0;
    *(uint8_t*)0x20d03fdc = 0;
    *(uint8_t*)0x20d03fdd = 0;
    *(uint8_t*)0x20d03fde = 0;
    *(uint8_t*)0x20d03fdf = 0xaa;
    *(uint32_t*)0x20d03fe0 = 0;
    *(uint16_t*)0x20d03fe4 = 0;
    *(uint16_t*)0x20d03fe6 = 0;
    *(uint32_t*)0x20d03fe8 = 0;
    *(uint64_t*)0x20d03ff0 = 4;
    *(uint32_t*)0x20d03ff8 = 0xc100bf;
    *(uint32_t*)0x20d03ffc = r[3];
    syscall(__NR_ioctl, r[2], 0x890b, 0x20d03fb0);
    break;
  case 8:
    r[4] = syscall(__NR_socket, 0xa, 1, 0);
    break;
  case 9:
    *(uint64_t*)0x20fd7000 = htobe64(0);
    *(uint64_t*)0x20fd7008 = htobe64(1);
    *(uint8_t*)0x20fd7010 = 0xfe;
    *(uint8_t*)0x20fd7011 = 0x80;
    *(uint8_t*)0x20fd7012 = 0;
    *(uint8_t*)0x20fd7013 = 0;
    *(uint8_t*)0x20fd7014 = 0;
    *(uint8_t*)0x20fd7015 = 0;
    *(uint8_t*)0x20fd7016 = 0;
    *(uint8_t*)0x20fd7017 = 0;
    *(uint8_t*)0x20fd7018 = 0;
    *(uint8_t*)0x20fd7019 = 0;
    *(uint8_t*)0x20fd701a = 0;
    *(uint8_t*)0x20fd701b = 0;
    *(uint8_t*)0x20fd701c = 0;
    *(uint8_t*)0x20fd701d = 0;
    *(uint8_t*)0x20fd701e = 0;
    *(uint8_t*)0x20fd701f = 0xbb;
    *(uint8_t*)0x20fd7020 = -1;
    *(uint8_t*)0x20fd7021 = 1;
    *(uint8_t*)0x20fd7022 = 0;
    *(uint8_t*)0x20fd7023 = 0;
    *(uint8_t*)0x20fd7024 = 0;
    *(uint8_t*)0x20fd7025 = 0;
    *(uint8_t*)0x20fd7026 = 0;
    *(uint8_t*)0x20fd7027 = 0;
    *(uint8_t*)0x20fd7028 = 0;
    *(uint8_t*)0x20fd7029 = 0;
    *(uint8_t*)0x20fd702a = 0;
    *(uint8_t*)0x20fd702b = 0;
    *(uint8_t*)0x20fd702c = 0;
    *(uint8_t*)0x20fd702d = 0;
    *(uint8_t*)0x20fd702e = 0;
    *(uint8_t*)0x20fd702f = 1;
    *(uint32_t*)0x20fd7030 = 0;
    *(uint16_t*)0x20fd7034 = 0;
    *(uint16_t*)0x20fd7036 = 0x40;
    *(uint32_t*)0x20fd7038 = 0;
    *(uint64_t*)0x20fd7040 = 0;
    *(uint32_t*)0x20fd7048 = 0;
    *(uint32_t*)0x20fd704c = 1;
    syscall(__NR_ioctl, r[4], 0x890b, 0x20fd7000);
    break;
  }
}

void test()
{
  memset(r, -1, sizeof(r));
  execute(10);
}

int main()
{
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        int pid = do_sandbox_none(procid, false);
        int status = 0;
        while (waitpid(pid, &status, __WALL) != pid) {
        }
      }
    }
  }
  sleep(1000000);
  return 0;
}