matcher: fix UB bug caused by dereferencing a bad optional (#14271)

Snow Pettersen · web-flow · commit ebdcf7cc28df · 2020-12-07T12:52:30.000-05:00
Signed-off-by: Snow Pettersen &lt;snowp@lyft.com&gt;
diff --git a/source/common/matcher/field_matcher.h b/source/common/matcher/field_matcher.h
@@ -16,7 +16,12 @@ struct FieldMatchResult {
   // The result, if matching was completed.
   absl::optional<bool> result_;
 
-  bool result() const { return *result_; }
+  // The unwrapped result. Should only be called if match_state_ == MatchComplete.
+  bool result() const {
+    ASSERT(match_state_ == MatchState::MatchComplete);
+    ASSERT(result_.has_value());
+    return *result_;
+  }
 };
 
 /**
@@ -87,6 +92,7 @@ template <class DataType> class AnyFieldMatcher : public FieldMatcher<DataType>
 
       if (result.match_state_ == MatchState::UnableToMatch) {
         unable_to_match_some_matchers = true;
+        continue;
       }
 
       if (result.result()) {
