static struct wait_queue_head *sock_get_poll_head(struct file *file,
		__poll_t events)
{
	struct socket *sock = file->private_data;

	if (!sock->ops->poll_mask)
		return NULL;
	sock_poll_busy_loop(sock, events);
	return sk_sleep(sock->sk);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.