comedi: dt2815: Add sanity checks for I/O base address

The "dt2815" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a DT2815
board.  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/20260130170416.49994-23-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/comedi/drivers/dt2815.c b/drivers/comedi/drivers/dt2815.c
index 03ba2fd18a216930be179051a251cbb740fae592..3fa1844515234a432de271758093fe545a1aa61a 100644 (file)
--- a/drivers/comedi/drivers/dt2815.c
+++ b/drivers/comedi/drivers/dt2815.c
@@ -144,7 +144,8 @@ static int dt2815_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        const struct comedi_lrange *current_range_type, *voltage_range_type;
        int ret;
 
-       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;