From roel.kluin@gmail.com  Thu Aug 13 16:49:04 2009
From: Roel Kluin <roel.kluin@gmail.com>
Date: Sat, 08 Aug 2009 00:14:20 +0200
Subject: Staging: comedi: s626: Possible read buffer overflow fix
To: Greg Kroah-Hartman <gregkh@suse.de>, wfp5p@virginia.edu, devel@driverdev.osuosl.org, Andrew Morton <akpm@linux-foundation.org>
Message-ID: <4A7CA73C.7090607@gmail.com>


If `cmd->chanlist_len' is 0, then we write ppl[-1].

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/staging/comedi/drivers/s626.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/staging/comedi/drivers/s626.c
+++ b/drivers/staging/comedi/drivers/s626.c
@@ -1707,7 +1707,8 @@ static int s626_ai_load_polllist(uint8_t
 		else
 			ppl[n] = (CR_CHAN((cmd->chanlist)[n])) | (RANGE_10V);
 	}
-	ppl[n - 1] |= EOPL;
+	if (n != 0)
+		ppl[n - 1] |= EOPL;
 
 	return n;
 }