On 19/04/17 19:15, Arnd Bergmann wrote:
> 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.
Oops! You're right, it should be strlcat.
Which gcc version do you use? Mine (6.3.0) didn't give an error (or warning, for that matter).
Regards,
Hans
>
> Fixes: 0f314f6c2e77 ("[media] rainshadow-cec: new RainShadow Tech HDMI CEC driver")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> 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);
>
