static int pmcraid_chr_fasync(int fd, struct file *filep, int mode)
{
	struct pmcraid_instance *pinstance;
	int rc;

	pinstance = filep->private_data;
	mutex_lock(&pinstance->aen_queue_lock);
	rc = fasync_helper(fd, filep, mode, &pinstance->aen_queue);
	mutex_unlock(&pinstance->aen_queue_lock);

	return rc;
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.