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authorIan Abbott <abbotti@mev.co.uk>2026-01-30 19:48:06 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2026-04-02 16:49:40 +0300
commitc375d40dc77c449ded79675b6ae00d82e67559bd (patch)
tree66b94a2c04946d74e50d6c0f6906ed287bb4b021
parent0ca9f8150ce5a41a3b4bb65f043f0335e7ef67b5 (diff)
downloadlinux-c375d40dc77c449ded79675b6ae00d82e67559bd.tar.xz
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 <abbotti@mev.co.uk> Link: https://patch.msgid.link/20260130170416.49994-42-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/comedi/drivers/pcmda12.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/comedi/drivers/pcmda12.c b/drivers/comedi/drivers/pcmda12.c
index 611f13bedca0..6efd1ae6271a 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;