From: Roel Kluin <roel.kluin@gmail.com>
Date: Fri, 7 Aug 2009 22:14:20 +0000 (+0200)
Subject: Staging: comedi: s626: Possible read buffer overflow fix
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4ff863b1db411481971de481002aa644057b1fa6;p=openwrt%2Fstaging%2Fblogic.git

Staging: comedi: s626: Possible read buffer overflow fix

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>
---

diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c
index 6549d116f2e6..80d2787d1063 100644
--- 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 * ppl, struct comedi_cmd *cmd)
 		else
 			ppl[n] = (CR_CHAN((cmd->chanlist)[n])) | (RANGE_10V);
 	}
-	ppl[n - 1] |= EOPL;
+	if (n != 0)
+		ppl[n - 1] |= EOPL;
 
 	return n;
 }