syzkaller-repros/linux/3fc16c8757592a555c9b2faa8757f60d2bdcaacc.c

// 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 <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 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 (running)
          usleep((call == num_calls - 1) ? 10000 : 1000);
        break;
      }
    }
  }
}

uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
  long res;
  switch (call) {
  case 0:
    memcpy((void*)0x20000000, "./cgroup.cpu/syz0", 18);
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000000, 0x200002, 0);
    if (res != -1)
      r[0] = res;
    break;
  case 1:
    syscall(__NR_flock, r[0], 0xe);
    break;
  case 2:
    memcpy((void*)0x20000040, "syz0", 5);
    syscall(__NR_mkdirat, -1, 0x20000040, 0x1ff);
    break;
  case 3:
    syscall(__NR_mincore, 0x20ffa000, 0x3000, 0x200000c0);
    break;
  case 4:
    syscall(__NR_ioctl, -1, 0x5425, 0x81);
    break;
  case 5:
    memcpy((void*)0x20000080, "/dev/ptmx", 10);
    res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000080, 0x400000, 0);
    if (res != -1)
      r[1] = res;
    break;
  case 6:
    *(uint64_t*)0x20001540 = 0x20000180;
    *(uint64_t*)0x20001548 = 0xe3;
    *(uint64_t*)0x20001550 = 0x20000280;
    *(uint64_t*)0x20001558 = 0xaf;
    *(uint64_t*)0x20001560 = 0x20000340;
    *(uint64_t*)0x20001568 = 0x7a;
    *(uint64_t*)0x20001570 = 0x200003c0;
    *(uint64_t*)0x20001578 = 0x23;
    *(uint64_t*)0x20001580 = 0x20000400;
    *(uint64_t*)0x20001588 = 0x23;
    *(uint64_t*)0x20001590 = 0x20000440;
    *(uint64_t*)0x20001598 = 0xda;
    *(uint64_t*)0x200015a0 = 0x20000540;
    *(uint64_t*)0x200015a8 = 0x1000;
    syscall(__NR_readv, r[1], 0x20001540, 7);
    break;
  }
}

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

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