card_number_show_attr(struct device *dev,
		     struct device_attribute *attr, char *buf)
{
	struct snd_card *card = container_of(dev, struct snd_card, card_dev);
	return snprintf(buf, PAGE_SIZE, "%i\n", card->number);
}

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.