linux-kernel - [PATCH] [media] rainshadow-cec: use strlcat instead of strncat

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Date:   Wed, 19 Apr 2017 19:15:32 +0200
From:   Arnd Bergmann <arnd@...db.de>
To:     Hans Verkuil <hverkuil@...all.nl>,
        Mauro Carvalho Chehab <mchehab@...nel.org>
Cc:     Arnd Bergmann <arnd@...db.de>, linux-media@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] [media] rainshadow-cec: use strlcat instead of strncat

gcc warns about an obviously incorrect use of strncat():

drivers/media/usb/rainshadow-cec/rainshadow-cec.c: In function 'rain_cec_adap_transmit':
drivers/media/usb/rainshadow-cec/rainshadow-cec.c:299:4: error: specified bound 48 equals the size of the destination [-Werror=stringop-overflow=]

It seems that strlcat was intended here, and using that makes the
code correct.

Fixes: 0f314f6c2e77 ("[media] rainshadow-cec: new RainShadow Tech HDMI CEC driver")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
 drivers/media/usb/rainshadow-cec/rainshadow-cec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
index 541ca543f71f..dc1f64f904cd 100644
--- a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
+++ b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c
@@ -296,7 +296,7 @@ static int rain_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
 			 cec_msg_destination(msg), msg->msg[1]);
 		for (i = 2; i < msg->len; i++) {
 			snprintf(hex, sizeof(hex), "%02x", msg->msg[i]);
-			strncat(cmd, hex, sizeof(cmd));
+			strlcat(cmd, hex, sizeof(cmd));
 		}
 	}
 	mutex_lock(&rain->write_lock);
-- 
2.9.0