From: Ian Abbott <abbotti@mev.co.uk>
Date: Thu, 15 Dec 2011 20:47:07 +0000 (+0000)
Subject: quatech_daqp_cs: don't access *data when insn->n == 0
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=77ebc7f8d65f976af8ba79f236061ea4361fa0cb;p=comedi.git

quatech_daqp_cs: don't access *data when insn->n == 0

Due to recent change to do_insnlist_ioctl() and do_insn_ioctl(), the
'data' pointer will be NULL when insn->n == 0.  Do not access *data
in this case.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---

diff --git a/comedi/drivers/quatech_daqp_cs.c b/comedi/drivers/quatech_daqp_cs.c
index b9c1a541..fb175054 100644
--- a/comedi/drivers/quatech_daqp_cs.c
+++ b/comedi/drivers/quatech_daqp_cs.c
@@ -825,6 +825,9 @@ static int daqp_ao_insn_write(comedi_device * dev, comedi_subdevice * s,
 		return -EIO;
 	}
 
+	if (insn->n == 0)
+		return 0;
+
 	chan = CR_CHAN(insn->chanspec);
 	d = data[0];
 	d &= 0x0fff;
@@ -866,6 +869,9 @@ static int daqp_do_insn_write(comedi_device * dev, comedi_subdevice * s,
 		return -EIO;
 	}
 
+	if (insn->n == 0)
+		return 0;
+
 	outw(data[0] & 0xf, dev->iobase + DAQP_DIGITAL_IO);
 
 	return 1;