syzkaller-repros/linux/ae8cd67e7e816f210105fee7719de41d6bcd010c.c

// INFO: task hung in fuse_reverse_inval_entry
// https://syzkaller.appspot.com/bug?id=ae8cd67e7e816f210105fee7719de41d6bcd010c
// 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>

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 (__atomic_load_n(&running, __ATOMIC_RELAXED))
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[1] = {0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    memcpy((void*)0x20000000, "./file0", 8);
    syscall(__NR_mkdirat, 0xffffff9c, 0x20000000, 0);
    break;
  case 1:
    memcpy((void*)0x20000640, "/dev/fuse", 10);
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000640, 2, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 2:
    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[0]);
    *(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 3:
    syscall(__NR_read, r[0], 0x20002000, 0x1000);
    break;
  case 4:
    syscall(__NR_pread64, r[0], 0x20000540, 0xec, 0);
    break;
  case 5:
    *(uint32_t*)0x20000100 = 0x50;
    *(uint32_t*)0x20000104 = 0;
    *(uint64_t*)0x20000108 = 1;
    *(uint32_t*)0x20000110 = 7;
    *(uint32_t*)0x20000114 = 0x1b;
    *(uint32_t*)0x20000118 = 0;
    *(uint32_t*)0x2000011c = 0;
    *(uint16_t*)0x20000120 = 0;
    *(uint16_t*)0x20000122 = 0;
    *(uint32_t*)0x20000124 = 0;
    *(uint32_t*)0x20000128 = 0;
    *(uint32_t*)0x2000012c = 0;
    *(uint32_t*)0x20000130 = 0;
    *(uint32_t*)0x20000134 = 0;
    *(uint32_t*)0x20000138 = 0;
    *(uint32_t*)0x2000013c = 0;
    *(uint32_t*)0x20000140 = 0;
    *(uint32_t*)0x20000144 = 0;
    *(uint32_t*)0x20000148 = 0;
    *(uint32_t*)0x2000014c = 0;
    syscall(__NR_write, r[0], 0x20000100, 0x50);
    break;
  case 6:
    memcpy((void*)0x20000500, "./file0/file0", 14);
    syscall(__NR_mkdirat, 0xffffff9c, 0x20000500, 0);
    break;
  case 7:
    *(uint32_t*)0x200000c0 = 0x29;
    *(uint32_t*)0x200000c4 = 3;
    *(uint64_t*)0x200000c8 = 0;
    *(uint64_t*)0x200000d0 = 1;
    *(uint32_t*)0x200000d8 = 8;
    *(uint32_t*)0x200000dc = 0;
    memcpy((void*)0x200000e0, "group_id", 8);
    *(uint8_t*)0x200000e8 = 0;
    syscall(__NR_write, r[0], 0x200000c0, 0x29);
    break;
  }
}

void loop()
{
  execute(8);
}

int main()
{
  syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
  loop();
  return 0;
}