--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -86,7 +86,7 @@ static int trailer_rcv(struct sk_buff *s
 
 	trailer = skb_tail_pointer(skb) - 4;
 	if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
-	    (trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00)
+	    (trailer[2] & 0xef) != 0x00 || (trailer[3] & 0xfe) != 0x00)
 		goto out_drop;
 
 	source_port = trailer[1] & 7;