[ 035/147] staging: comedi: dont dereference user memory for INSN_INTTRIG

Ben Hutchings
2012-10-14T14:49:05Z

From: Ian Abbott <abbotti@mev.co.uk>

commit 5d06e3df280bd230e2eadc16372e62818c63e894 upstream.

`parse_insn()` is dereferencing the user-space pointer `insn->data`
directly when handling the `INSN_INTTRIG` comedi instruction. It
shouldn't be using `insn->data` at all; it should be using the separate
`data` pointer passed to the function. Fix it.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/staging/comedi/comedi_fops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index 9b9d4e8..f496f4d 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -950,7 +950,7 @@ static int parse_insn(struct comedi_device *dev, struct comedi_insn *insn,
ret = -EAGAIN;
break;
}
- ret = s->async->inttrig(dev, s, insn->data[0]);
+ ret = s->async->inttrig(dev, s, data[0]);
if (ret >= 0)
ret = 1;
break;