[PATCH] comedi: aio_iiro_16: Prevent invlaid irq number

[Edward Adam Davis]

The irq number 0x2166 passed by the reproducer is too large and is not
within the supported range [2-7, 10-12, 14, or 15], which triggers the oob.

Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection")
Reported-by: syzbot+f1bb7e4ea47ea12b535c@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=f1bb7e4ea47ea12b535c
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
---
 drivers/comedi/drivers/aio_iiro_16.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/aio_iiro_16.c b/drivers/comedi/drivers/aio_iiro_16.c
index b00fab0b89d4..e43730f00c8b 100644
--- a/drivers/comedi/drivers/aio_iiro_16.c
+++ b/drivers/comedi/drivers/aio_iiro_16.c
@@ -177,7 +177,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev,
 	 * Digital input change of state interrupts are optionally supported
 	 * using IRQ 2-7, 10-12, 14, or 15.
 	 */
-	if ((1 << it->options[1]) & 0xdcfc) {
+	if (it->options[1] > 1 && it->options[1] < 16 &&
+	    (1 << it->options[1]) & 0xdcfc) {
 		ret = request_irq(it->options[1], aio_iiro_16_cos, 0,
 				  dev->board_name, dev);
 		if (ret == 0)
-- 
2.43.0