comedi: dt2801: Add sanity checks for I/O base address

The "dt2801" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a supported
board in the DT2801 family.  It currently allows any base address to be
configured but the hardware only supports base addresses (configured by
an on-board DIP switch) in the range 0x200 to 0x3fe on 2-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>
Link: https://patch.msgid.link/20260130170416.49994-20-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/comedi/drivers/dt2801.c b/drivers/comedi/drivers/dt2801.c
index 230d25010f5800b5ae17258dfb0e546972455500..d790e69f98a053d3a81309a4aec9ced63ab295b5 100644 (file)
--- a/drivers/comedi/drivers/dt2801.c
+++ b/drivers/comedi/drivers/dt2801.c
@@ -540,7 +540,8 @@ static int dt2801_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        int ret = 0;
        int n_ai_chans;
 
-       ret = comedi_request_region(dev, it->options[0], 0x2);
+       ret = comedi_check_request_region(dev, it->options[0], 0x2,
+                                         0x200, 0x3ff, 2);
        if (ret)
                return ret;