--- x/drivers/comedi/drivers/pcl812.c
+++ y/drivers/comedi/drivers/pcl812.c
@@ -1148,6 +1148,8 @@ static int pcl812_attach(struct comedi_d
 					 I8254_OSC_BASE_2MHZ, I8254_IO8, 0);
 		if (IS_ERR(dev->pacer))
 			return PTR_ERR(dev->pacer);
+		if (it->options[1] < 0 || it->options[1] > 31)
+			return -EINVAL;
 
 		if ((1 << it->options[1]) & board->irq_bits) {
 			ret = request_irq(it->options[1], pcl812_interrupt, 0,