Limit the number of warnings in json_fuzzer before giving up

m-holger
1 parent e14e828c
Showing 2 changed files with 12 additions and 6 deletions
fuzz/json_fuzzer.cc
libqpdf/QPDF_json.cc
@@ -33,6 +33,7 @@ FuzzHelper::doChecks()
         std::cerr << "runtime_error parsing json: " << e.what() << std::endl;
     }
     QPDF q;
+    q.setMaxWarnings(1000);
     Buffer buf(const_cast<unsigned char*>(data), size);
     auto is = std::make_shared<BufferInputSource>("json", &buf);
     q.createFromJSON(is);
@@ -233,12 +233,13 @@ provide_data(std::shared_ptr&lt;InputSource&gt; is, qpdf_offset_t start, qpdf_offset_t
 class QPDF::JSONReactor: public JSON::Reactor
 {
   public:
-    JSONReactor(QPDF& pdf, std::shared_ptr<InputSource> is, bool must_be_complete) :
+    JSONReactor(QPDF& pdf, std::shared_ptr<InputSource> is, bool must_be_complete, int max_warnings) :
         pdf(pdf),
         is(is),
         must_be_complete(must_be_complete),
         descr(std::make_shared<QPDFValue::Description>(
-            QPDFValue::JSON_Descr(std::make_shared<std::string>(is->getName()), "")))
+            QPDFValue::JSON_Descr(std::make_shared<std::string>(is->getName()), ""))),
+        max_warnings(max_warnings)
     {
         for (auto& oc: pdf.m->obj_cache) {
             if (oc.second.object->getTypeCode() == ::ot_reserved) {
@@ -291,7 +292,8 @@ class QPDF::JSONReactor: public JSON::Reactor
     std::shared_ptr<InputSource> is;
     bool must_be_complete{true};
     std::shared_ptr<QPDFValue::Description> descr;
-    bool errors{false};
+    int errors{0};
+    int max_warnings{0};
     bool saw_qpdf{false};
     bool saw_qpdf_meta{false};
     bool saw_objects{false};
@@ -314,18 +316,21 @@ class QPDF::JSONReactor: public JSON::Reactor
 void
 QPDF::JSONReactor::error(qpdf_offset_t offset, std::string const& msg)
 {
-    this->errors = true;
+    ++errors;
     std::string object = this->cur_object;
     if (is->getName() != pdf.getFilename()) {
         object += " from " + is->getName();
     }
     this->pdf.warn(qpdf_e_json, object, offset, msg);
+    if (max_warnings > 0 && errors >= max_warnings) {
+        throw std::runtime_error("errors found in JSON");
+    }
 }
 bool
 QPDF::JSONReactor::anyErrors() const
 {
-    return this->errors;
+    return errors > 0;
 }
 void
@@ -820,7 +825,7 @@ QPDF::updateFromJSON(std::shared_ptr&lt;InputSource&gt; is)
 void
 QPDF::importJSON(std::shared_ptr<InputSource> is, bool must_be_complete)
 {
-    JSONReactor reactor(*this, is, must_be_complete);
+    JSONReactor reactor(*this, is, must_be_complete, m->max_warnings);
     try {
         JSON::parse(*is, &reactor);
     } catch (std::runtime_error& e) {