// https://syzkaller.appspot.com/bug?id=c5f3199cfcf4d6f57d92bc76bf2f138350829e2d // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include 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 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[1] = {0xffffffffffffffff}; uint64_t procid; void execute_call(int call) { long res; switch (call) { case 0: memcpy((void*)0x20000000, "/dev/ashmem", 12); res = syscall(__NR_openat, 0xffffffffffffff9c, 0x20000000, 0, 0); if (res != -1) r[0] = res; break; case 1: syscall(__NR_ioctl, r[0], 0x40087703, 0x400); break; case 2: syscall(__NR_mmap, 0x20447000, 0x4000, 0, 0x13, r[0], 0); break; case 3: syscall(__NR_ioctl, r[0], 0x7709, 0); break; case 4: syscall(__NR_mmap, 0x20448000, 0x2000, 2, 0x8012, r[0], 0); break; } } void test() { execute(5); collide = 1; execute(5); } 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; }