media: rc: check for integer overflow

The ioctl LIRC_SET_REC_TIMEOUT would set a timeout of 704ns if called
with a timeout of 4294968us.

Cc: <stable@vger.kernel.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/rc/ir-lirc-codec.c

@@ -298,11 +298,14 @@ static long ir_lirc_ioctl(struct file *filep, unsigned int cmd,
 		if (!dev->max_timeout)
 			return -ENOTTY;
 
+		/* Check for multiply overflow */
+		if (val > U32_MAX / 1000)
+			return -EINVAL;
+
 		tmp = val * 1000;
 
-		if (tmp < dev->min_timeout ||
-		    tmp > dev->max_timeout)
-				return -EINVAL;
+		if (tmp < dev->min_timeout || tmp > dev->max_timeout)
+			return -EINVAL;
 
 		if (dev->s_timeout)
 			ret = dev->s_timeout(dev, tmp);