--- b6cef980095fe745340dc78ce550ed20985c91e9
+++ 476b24ee7b712fa4c65b9fd160c2a63b2dfbe18a
@@ -2164,6 +2164,14 @@ static int irda_getsockopt(struct socket
 
 	switch (optname) {
 	case IRLMP_ENUMDEVICES:
+
+		/* Offset to first device entry */
+		offset = sizeof(struct irda_device_list) -
+			sizeof(struct irda_device_info);
+
+		if (len < offset)
+			return -EINVAL;
+
 		/* Ask lmp for the current discovery log */
 		discoveries = irlmp_get_discoveries(&list.len, self->mask.word,
 						    self->nslots);
@@ -2173,15 +2181,9 @@ static int irda_getsockopt(struct socket
 		err = 0;
 
 		/* Write total list length back to client */
-		if (copy_to_user(optval, &list,
-				 sizeof(struct irda_device_list) -
-				 sizeof(struct irda_device_info)))
+		if (copy_to_user(optval, &list, offset))
 			err = -EFAULT;
 
-		/* Offset to first device entry */
-		offset = sizeof(struct irda_device_list) -
-			sizeof(struct irda_device_info);
-
 		/* Copy the list itself - watch for overflow */
 		if(list.len > 2048)
 		{