From b639fa305d71b2f3c9a19d20e186beee16408b0c Mon Sep 17 00:00:00 2001
From: Miek Gieben <miek@miek.nl>
Date: Sun, 29 Jan 2012 19:11:55 +0100
Subject: [PATCH] Fix overflow when the buffer is really small

---
 msg.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/msg.go b/msg.go
index f629af98..93bbc80a 100644
--- a/msg.go
+++ b/msg.go
@@ -806,8 +806,12 @@ func unpackStructValue(val reflect.Value, msg []byte, off int) (off1 int, ok boo
 					// Work because of rfc4034, section 3.17
 					consumed += len(val.FieldByName("SignerName").String()) + 1
 				default:
-					consumed = 0 // TODO
+					consumed = 0 // TODO, maybe error?
 				}
+                                if off+rdlength-consumed > lenmsg {
+                                        println("dns: failure unpacking base64")
+                                        return lenmsg, false
+                                }
 				s = unpackBase64(msg[off : off+rdlength-consumed])
 				off += rdlength - consumed
 			case "cdomain-name":