1 files changed, 93 insertions, 0 deletions
diff --git a/testing/fuzzers/pdf_hint_table_fuzzer.cc b/testing/fuzzers/pdf_hint_table_fuzzer.cc
new file mode 100644
index 0000000000..50ca5cd693
--- /dev/null
+++ b/testing/fuzzers/pdf_hint_table_fuzzer.cc
@@ -0,0 +1,93 @@
+// Copyright 2016 The PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <cstdint>
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_boolean.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_hint_tables.h"
+#include "core/fpdfapi/parser/cpdf_linearized_header.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
+#include "core/fxcrt/cfx_bitstream.h"
+#include "third_party/base/ptr_util.h"
+#include "third_party/base/span.h"
+
+int32_t GetData(const int32_t** data32, const uint8_t** data, size_t* size) {
+  const int32_t* ret = *data32;
+  ++(*data32);
+  *data += 4;
+  *size -= 4;
+  return *ret;
+}
+
+class HintTableForFuzzing : public CPDF_HintTables {
+ public:
+  HintTableForFuzzing(CPDF_LinearizedHeader* pLinearized,
+                      int shared_hint_table_offset)
+      : CPDF_HintTables(nullptr, pLinearized),
+        shared_hint_table_offset_(shared_hint_table_offset) {}
+  ~HintTableForFuzzing() {}
+
+  void Fuzz(const uint8_t* data, size_t size) {
+    if (shared_hint_table_offset_ <= 0)
+      return;
+
+    if (size < static_cast<size_t>(shared_hint_table_offset_))
+      return;
+
+    CFX_BitStream bs(pdfium::make_span(data, size));
+    if (!ReadPageHintTable(&bs))
+      return;
+    ReadSharedObjHintTable(&bs, shared_hint_table_offset_);
+  }
+
+ private:
+  int shared_hint_table_offset_;
+};
+
+class FakeLinearized : public CPDF_LinearizedHeader {
+ public:
+  explicit FakeLinearized(CPDF_Dictionary* linearized_dict)
+      : CPDF_LinearizedHeader(linearized_dict, 0) {}
+};
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  // Need 28 bytes for |linearized_dict|.
+  // The header section of page offset hint table is 36 bytes.
+  // The header section of shared object hint table is 24 bytes.
+  if (size < 28 + 36 + 24)
+    return 0;
+
+  const int32_t* data32 = reinterpret_cast<const int32_t*>(data);
+
+  auto linearized_dict = pdfium::MakeUnique<CPDF_Dictionary>();
+  // Set initial value.
+  linearized_dict->SetNewFor<CPDF_Boolean>("Linearized", true);
+  // Set first page end offset
+  linearized_dict->SetNewFor<CPDF_Number>("E", GetData(&data32, &data, &size));
+  // Set page count
+  linearized_dict->SetNewFor<CPDF_Number>("N", GetData(&data32, &data, &size));
+  // Set first page obj num
+  linearized_dict->SetNewFor<CPDF_Number>("O", GetData(&data32, &data, &size));
+  // Set first page no
+  linearized_dict->SetNewFor<CPDF_Number>("P", GetData(&data32, &data, &size));
+
+  auto hint_info = pdfium::MakeUnique<CPDF_Array>();
+  // Add primary hint stream offset
+  hint_info->AddNew<CPDF_Number>(GetData(&data32, &data, &size));
+  // Add primary hint stream size
+  hint_info->AddNew<CPDF_Number>(GetData(&data32, &data, &size));
+  // Set hint stream info.
+  linearized_dict->SetFor("H", std::move(hint_info));
+
+  const int shared_hint_table_offset = GetData(&data32, &data, &size);
+
+  {
+    FakeLinearized linearized(linearized_dict.get());
+    HintTableForFuzzing hint_table(&linearized, shared_hint_table_offset);
+    hint_table.Fuzz(data, size);
+  }
+  return 0;
+}