rec: a name can be present already when building the cname chain

diff --git a/pdns/recursordist/syncres.cc b/pdns/recursordist/syncres.cc
index 282944f54453634e25717f32fa52c681fd5e977a..e87206292ccce014244eefc7bf380472784d23ee 100644 (file)
--- a/pdns/recursordist/syncres.cc
+++ b/pdns/recursordist/syncres.cc
@@ -4395,7 +4395,10 @@ RCode::rcodes_ SyncRes::updateCacheFromRecords(unsigned int depth, const string&
         break;
       }
       initial = cnameIt->second;
-      wildcardCandidates.emplace(initial, false);
+      if (!wildcardCandidates.emplace(initial, false).second) {
+        // CNAME Loop
+        break;
+      }
     }
   }