From 67301a1c233e224c837b82bda8bcf9ea44ad93c1 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Thu, 7 Dec 2017 12:31:26 +0100
Subject: [PATCH] p2p/enr: check size limit when decoding

---
 p2p/enr/enr.go | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/p2p/enr/enr.go b/p2p/enr/enr.go
index 594c385d0d..b84f3ca880 100644
--- a/p2p/enr/enr.go
+++ b/p2p/enr/enr.go
@@ -33,11 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/rlp"
 )
 
-const (
-	// SizeLimit is the maximum encoded size of a node record in bytes.
-	// Implementations should reject records larger than this size.
-	SizeLimit = 300
-)
+const SizeLimit = 300 // maximum encoded size of a node record in bytes
 
 var (
 	errNoID           = errors.New("unknown or unspecified identity scheme")
@@ -140,6 +136,9 @@ func (r *Record) DecodeRLP(s *rlp.Stream) error {
 	if err != nil {
 		return err
 	}
+	if len(raw) > SizeLimit {
+		return errTooBig
+	}
 
 	// Decode the RLP container.
 	dec := Record{raw: raw}