From 7a40584f66f3c5d18300358653ca9e6318eda9ab Mon Sep 17 00:00:00 2001
From: Matt Liggett <mml@google.com>
Date: Thu, 23 Jun 2016 08:39:02 -0700
Subject: [PATCH] Verify that the we get a non-nil subtree before consulting
 it.

Fixes #27919
---
 pkg/dns/treecache.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pkg/dns/treecache.go b/pkg/dns/treecache.go
index d6c9c77c23d..6f7a9aa1fba 100644
--- a/pkg/dns/treecache.go
+++ b/pkg/dns/treecache.go
@@ -98,6 +98,9 @@ func (cache *TreeCache) setSubCache(key string, subCache *TreeCache, path ...str
 
 func (cache *TreeCache) getEntry(key string, path ...string) (interface{}, bool) {
 	childNode := cache.getSubCache(path...)
+	if childNode == nil {
+		return nil, false
+	}
 	val, ok := childNode.Entries[key]
 	return val, ok
 }