The "rti800" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a RTI-800
or RTI-815 board.  It currently allows any base address to be configured
but the hardware only supports base addresses (configured by on-board
DIP switches) in the range 0 to 0x3F0 on 16-byte boundaries.

Add a sanity check to ensure the device is not configured at an
unsupported base address.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/comedi/drivers/rti800.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/rti800.c b/drivers/comedi/drivers/rti800.c
index 1b02e47bdb4c..fa3965cf92f2 100644
--- a/drivers/comedi/drivers/rti800.c
+++ b/drivers/comedi/drivers/rti800.c
@@ -257,7 +257,8 @@ static int rti800_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	struct comedi_subdevice *s;
 	int ret;
 
-	ret = comedi_request_region(dev, it->options[0], 0x10);
+	ret = comedi_check_request_region(dev, it->options[0], 0x10,
+					  0, 0x3ff, 16);
 	if (ret)
 		return ret;
 
-- 
2.51.0