comedi: dac02: Add sanity checks for I/O base address

The "dac02" driver uses an admin-supplied configuration option
(`it->options[0]`) to configure the I/O port base address of a supported
DAC-02 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 0x3f8 on 8-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/20260130170416.49994-12-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/comedi/drivers/dac02.c b/drivers/comedi/drivers/dac02.c
index 4b011d66d7b014ce3dfab30769d4ba3d91add394..2c04472c507825e75c4e57418e81dac5f3368dc0 100644 (file)
--- a/drivers/comedi/drivers/dac02.c
+++ b/drivers/comedi/drivers/dac02.c
@@ -103,7 +103,8 @@ static int dac02_attach(struct comedi_device *dev, struct comedi_devconfig *it)
        struct comedi_subdevice *s;
        int ret;
 
-       ret = comedi_request_region(dev, it->options[0], 0x08);
+       ret = comedi_check_request_region(dev, it->options[0], 0x08,
+                                         0x200, 0x3ff, 8);
        if (ret)
                return ret;