syzkaller-repros/linux/69c1eb1079b9db12bec3d4c6c90cdfe37ab6012c.c

// general protection fault in process_init_reply
// https://syzkaller.appspot.com/bug?id=69c1eb1079b9db12bec3d4c6c90cdfe37ab6012c
// status:open
// autogenerated by syzkaller (http://github.com/google/syzkaller)

#define _GNU_SOURCE
#include <endian.h>
#include <linux/futex.h>
#include <pthread.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/syscall.h>
#include <unistd.h>

static void execute_one();
extern unsigned long long procid;

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

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 int collide;

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);
        if (collide && call % 2)
          break;
        struct timespec ts;
        ts.tv_sec = 0;
        ts.tv_nsec = 20 * 1000 * 1000;
        syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
        if (__atomic_load_n(&running, __ATOMIC_RELAXED))
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
unsigned long long procid;
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    memcpy((void*)0x20000100, "./file0", 8);
    syscall(__NR_mknod, 0x20000100, 0, 0);
    break;
  case 1:
    memcpy((void*)0x20000740, "./file0", 8);
    res = syscall(__NR_open, 0x20000740, 0, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 2:
    *(uint32_t*)0x20000780 = -1;
    syscall(__NR_ioctl, r[0], 0x541b, 0x20000780);
    break;
  case 3:
    memcpy((void*)0x20000000, "./file0", 8);
    syscall(__NR_mkdirat, 0xffffff9c, 0x20000000, 0);
    break;
  case 4:
    memcpy((void*)0x20000100, "/dev/fuse", 10);
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000100, 2, 0);
    if (res != -1)
      r[1] = res;
    break;
  case 5:
    memcpy((void*)0x20000200, "./file0", 8);
    memcpy((void*)0x20000300, "fuse", 5);
    memcpy((void*)0x20000400, "fd", 2);
    *(uint8_t*)0x20000402 = 0x3d;
    sprintf((char*)0x20000403, "0x%016llx", (long long)r[1]);
    *(uint8_t*)0x20000415 = 0x2c;
    memcpy((void*)0x20000416, "rootmode", 8);
    *(uint8_t*)0x2000041e = 0x3d;
    sprintf((char*)0x2000041f, "%023llo", (long long)0x4000);
    *(uint8_t*)0x20000436 = 0x2c;
    memcpy((void*)0x20000437, "user_id", 7);
    *(uint8_t*)0x2000043e = 0x3d;
    sprintf((char*)0x2000043f, "%020llu", (long long)0);
    *(uint8_t*)0x20000453 = 0x2c;
    memcpy((void*)0x20000454, "group_id", 8);
    *(uint8_t*)0x2000045c = 0x3d;
    sprintf((char*)0x2000045d, "%020llu", (long long)0);
    *(uint8_t*)0x20000471 = 0x2c;
    *(uint8_t*)0x20000472 = 0;
    syscall(__NR_mount, 0, 0x20000200, 0x20000300, 0, 0x20000400);
    break;
  case 6:
    syscall(__NR_read, r[1], 0x20001000, 0x1000);
    break;
  }
}

void execute_one()
{
  execute(7);
  collide = 1;
  execute(7);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  for (procid = 0; procid < 8; procid++) {
    if (fork() == 0) {
      for (;;) {
        loop();
      }
    }
  }
  sleep(1000000);
  return 0;
}