The "amplc_pc236" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a supported
PC36AT board.  It currently allows any base address to be configured but
the hardware only supports base addresses (set by on-board DIP switches)
in the range 0 to 0xFFC on 4-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/amplc_pc236.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/comedi/drivers/amplc_pc236.c b/drivers/comedi/drivers/amplc_pc236.c
index b21e0c906aab..eadee10983bf 100644
--- a/drivers/comedi/drivers/amplc_pc236.c
+++ b/drivers/comedi/drivers/amplc_pc236.c
@@ -45,7 +45,8 @@ static int pc236_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	if (!devpriv)
 		return -ENOMEM;
 
-	ret = comedi_request_region(dev, it->options[0], 0x4);
+	ret = comedi_check_request_region(dev, it->options[0], 0x4,
+					  0, 0xfff, 4);
 	if (ret)
 		return ret;
 
-- 
2.51.0