int snd_card_file_add(struct snd_card *card, struct file *file)
{
	struct snd_monitor_file *mfile;

	mfile = kmalloc(sizeof(*mfile), GFP_KERNEL);
	if (mfile == NULL)
		return -ENOMEM;
	mfile->file = file;
	mfile->disconnected_f_op = NULL;
	INIT_LIST_HEAD(&mfile->shutdown_list);
	spin_lock(&card->files_lock);
	if (card->shutdown) {
		spin_unlock(&card->files_lock);
		kfree(mfile);
		return -ENODEV;
	}
	list_add(&mfile->list, &card->files_list);
	get_device(&card->card_dev);
	spin_unlock(&card->files_lock);
	return 0;
}

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.