From c375d40dc77c449ded79675b6ae00d82e67559bd Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Fri, 30 Jan 2026 16:48:06 +0000 Subject: [PATCH] comedi: pcmda12: Add sanity checks for I/O base address The "pcmda12" driver uses an admin-supplied configuration option (`it->options[0]`) to configure the I/O port base address of a PCM-D/A-12 or PCM-A/D-16 board. It currently allows any base address to be configured. I cannot find a full manual, but the short datasheet says it uses 15 consecutive I/O addresses on "any even sixteen port boundary", so assume it supports base addresses (configured by on-board jumpers) in the range 0 to 0x3E0 on 32-byte boundaries. Add a sanity check to ensure the device is not configured at an unsupported base address. Signed-off-by: Ian Abbott Link: https://patch.msgid.link/20260130170416.49994-42-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman --- drivers/comedi/drivers/pcmda12.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/comedi/drivers/pcmda12.c b/drivers/comedi/drivers/pcmda12.c index 611f13bedca05..6efd1ae6271a8 100644 --- a/drivers/comedi/drivers/pcmda12.c +++ b/drivers/comedi/drivers/pcmda12.c @@ -120,7 +120,14 @@ static int pcmda12_attach(struct comedi_device *dev, struct comedi_subdevice *s; int ret; - ret = comedi_request_region(dev, it->options[0], 0x10); + /* + * The datasheet says it requires 16 contiguous addresses and is + * "configurable on any even sixteen port boundary". So require + * a 32-byte boundary and assume it uses 10-bit addresses like + * similar boards. + */ + ret = comedi_check_request_region(dev, it->options[0], 0x10, + 0, 0x3ff, 32); if (ret) return ret; -- 2.47.3