From 5b13e1dc5770b73295f0c4a61c699a10eb7922e6 Mon Sep 17 00:00:00 2001 From: thestig Date: Fri, 19 Aug 2016 12:04:05 -0700 Subject: Add a fuzzer for CPDF_HintTables. BUG=636559 Review-Url: https://codereview.chromium.org/2255083004 --- core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp | 19 +++++- core/fpdfapi/fpdf_parser/cpdf_hint_tables.h | 15 +++-- testing/DEPS | 5 +- testing/libfuzzer/BUILD.gn | 15 +++++ testing/libfuzzer/pdf_hint_table_fuzzer.cc | 94 +++++++++++++++++++++++++++ 5 files changed, 136 insertions(+), 12 deletions(-) create mode 100644 testing/libfuzzer/pdf_hint_table_fuzzer.cc diff --git a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp index 4d48ab4bfa..f1e74dc6bc 100644 --- a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp +++ b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp @@ -60,6 +60,8 @@ bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) { // Item 1: The least number of objects in a page. uint32_t dwObjLeastNum = hStream->GetBits(32); + if (!dwObjLeastNum) + return FALSE; // Item 2: The location of the first page's page object. uint32_t dwFirstObjLoc = hStream->GetBits(32); @@ -78,13 +80,19 @@ bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) { // Item 3: The number of bits needed to represent the difference // between the greatest and least number of objects in a page. uint32_t dwDeltaObjectsBits = hStream->GetBits(16); + if (!dwDeltaObjectsBits) + return FALSE; // Item 4: The least length of a page in bytes. uint32_t dwPageLeastLen = hStream->GetBits(32); + if (!dwPageLeastLen) + return FALSE; // Item 5: The number of bits needed to represent the difference // between the greatest and least length of a page, in bytes. uint32_t dwDeltaPageLenBits = hStream->GetBits(16); + if (!dwDeltaPageLenBits) + return FALSE; // Skip Item 6, 7, 8, 9 total 96 bits. hStream->SkipBits(96); @@ -96,12 +104,16 @@ bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) { // Item 11: The number of bits needed to represent the numerically // greatest shared object identifier used by the pages. uint32_t dwSharedIdBits = hStream->GetBits(16); + if (!dwSharedObjBits) + return FALSE; // Item 12: The number of bits needed to represent the numerator of // the fractional position for each shared object reference. For each // shared object referenced from a page, there is an indication of // where in the page's content stream the object is first referenced. uint32_t dwSharedNumeratorBits = hStream->GetBits(16); + if (!dwSharedIdBits) + return FALSE; // Item 13: Skip Item 13 which has 16 bits. hStream->SkipBits(16); @@ -113,7 +125,7 @@ bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) { return false; const int nPages = GetNumberOfPages(); - if (nPages < 1) + if (nPages < 1 || nPages >= FPDF_PAGE_MAX_NUM) return false; const uint32_t dwPages = pdfium::base::checked_cast(nPages); @@ -136,13 +148,14 @@ bool CPDF_HintTables::ReadPageHintTable(CFX_BitStream* hStream) { if (!CanReadFromBitStream(hStream, required_bits)) return false; - CFX_ArrayTemplate dwPageLenArray; + std::vector dwPageLenArray; for (int i = 0; i < nPages; ++i) { FX_SAFE_UINT32 safePageLen = hStream->GetBits(dwDeltaPageLenBits); safePageLen += dwPageLeastLen; if (!safePageLen.IsValid()) return false; - dwPageLenArray.Add(safePageLen.ValueOrDie()); + + dwPageLenArray.push_back(safePageLen.ValueOrDie()); } int nOffsetE = GetEndOfFirstPageOffset(); diff --git a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.h b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.h index 35fbdcb79b..cda0925de8 100644 --- a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.h +++ b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.h @@ -20,7 +20,7 @@ class CPDF_Stream; class CPDF_HintTables { public: CPDF_HintTables(CPDF_DataAvail* pDataAvail, CPDF_Dictionary* pLinearized); - ~CPDF_HintTables(); + virtual ~CPDF_HintTables(); bool GetPagePos(int index, FX_FILESIZE* szPageStartPos, @@ -39,12 +39,13 @@ class CPDF_HintTables { uint32_t GetItemLength(int index, const std::vector& szArray); private: - int GetEndOfFirstPageOffset() const; - int GetNumberOfPages() const; - int GetFirstPageObjectNumber() const; - int GetFirstPageNumber() const; - int ReadPrimaryHintStreamOffset() const; - int ReadPrimaryHintStreamLength() const; + // Tests can override. + virtual int GetEndOfFirstPageOffset() const; + virtual int GetNumberOfPages() const; + virtual int GetFirstPageObjectNumber() const; + virtual int GetFirstPageNumber() const; + virtual int ReadPrimaryHintStreamOffset() const; + virtual int ReadPrimaryHintStreamLength() const; // Helper for the ReadPrimaryHintStream methods above. int ReadPrimaryHintStream(int index) const; diff --git a/testing/DEPS b/testing/DEPS index babefb8593..d3cc6f3869 100644 --- a/testing/DEPS +++ b/testing/DEPS @@ -1,13 +1,14 @@ include_rules = [ - '+core/include', + '+core/fpdfapi', '+core/fxcodec', '+core/fxcrt/include', '+core/fxge/include', + '+core/include', '+fxjs/include', '+public', '+v8', '+xfa/fde', '+xfa/fgas', - '+xfa/fxfa/parser', '+xfa/fxfa/fm2js', + '+xfa/fxfa/parser', ] diff --git a/testing/libfuzzer/BUILD.gn b/testing/libfuzzer/BUILD.gn index 718a1db3c0..811618d089 100644 --- a/testing/libfuzzer/BUILD.gn +++ b/testing/libfuzzer/BUILD.gn @@ -183,3 +183,18 @@ source_set("pdf_psengine_fuzzer") { ":libfuzzer_config", ] } + +source_set("pdf_hint_table_fuzzer") { + testonly = true + sources = [ + "pdf_hint_table_fuzzer.cc", + ] + deps = [ + "//third_party/pdfium:pdfium", + ] + configs -= [ "//build/config/compiler:chromium_code" ] + configs += [ + "//build/config/compiler:no_chromium_code", + ":libfuzzer_config", + ] +} diff --git a/testing/libfuzzer/pdf_hint_table_fuzzer.cc b/testing/libfuzzer/pdf_hint_table_fuzzer.cc new file mode 100644 index 0000000000..d14d9464f5 --- /dev/null +++ b/testing/libfuzzer/pdf_hint_table_fuzzer.cc @@ -0,0 +1,94 @@ +// 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 + +#include "core/fpdfapi/fpdf_parser/cpdf_hint_tables.h" +#include "core/fpdfapi/fpdf_parser/include/cpdf_dictionary.h" + +struct DummyLinearizedDictionary { + int end_of_first_page_offset; + int number_of_pages; + int first_page_object_number; + int first_page_number; + int primary_hint_stream_offset; + int primary_hint_stream_length; + int shared_hint_table_offset; +}; + +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(DummyLinearizedDictionary* dict, + CPDF_Dictionary* linearized_dict) + : CPDF_HintTables(nullptr, linearized_dict), dict_(dict) {} + ~HintTableForFuzzing() {} + + void Fuzz(const uint8_t* data, size_t size) { + if (dict_->shared_hint_table_offset <= 0) + return; + + if (size < static_cast(dict_->shared_hint_table_offset)) + return; + + CFX_BitStream bs; + bs.Init(data, size); + if (!ReadPageHintTable(&bs)) + return; + ReadSharedObjHintTable(&bs, dict_->shared_hint_table_offset); + } + + private: + int GetEndOfFirstPageOffset() const override { + return dict_->end_of_first_page_offset; + } + int GetNumberOfPages() const override { return dict_->number_of_pages; } + int GetFirstPageObjectNumber() const override { + return dict_->first_page_object_number; + } + int GetFirstPageNumber() const override { return dict_->first_page_number; } + int ReadPrimaryHintStreamOffset() const override { + return dict_->primary_hint_stream_offset; + } + int ReadPrimaryHintStreamLength() const override { + return dict_->primary_hint_stream_length; + } + + DummyLinearizedDictionary* const dict_; +}; + +extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) { + // Need 28 bytes for |dummy_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(data); + DummyLinearizedDictionary dummy_dict; + dummy_dict.end_of_first_page_offset = GetData(&data32, &data, &size); + dummy_dict.number_of_pages = GetData(&data32, &data, &size); + dummy_dict.first_page_object_number = GetData(&data32, &data, &size); + dummy_dict.first_page_number = GetData(&data32, &data, &size); + dummy_dict.primary_hint_stream_offset = GetData(&data32, &data, &size); + dummy_dict.primary_hint_stream_length = GetData(&data32, &data, &size); + dummy_dict.shared_hint_table_offset = GetData(&data32, &data, &size); + + CPDF_Dictionary* dummy_linearized_dict = new CPDF_Dictionary; + + { + HintTableForFuzzing hint_table(&dummy_dict, dummy_linearized_dict); + hint_table.Fuzz(data, size); + } + + dummy_linearized_dict->Release(); + return 0; +} -- cgit v1.2.3