static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
{
	struct ib_uverbs_completion_event_file *comp_ev_file =
		filp->private_data;

	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
}

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.