Add a fuzzer for CPDF_HintTables.
BUG=636559
Review-Url: https://codereview.chromium.org/2255083004
diff --git a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
index 4d48ab4..f1e74dc 100644
--- a/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
+++ b/core/fpdfapi/fpdf_parser/cpdf_hint_tables.cpp
@@ -60,6 +60,8 @@
// 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 @@
// 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 @@
// 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 @@
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<uint32_t>(nPages);
@@ -136,13 +148,14 @@
if (!CanReadFromBitStream(hStream, required_bits))
return false;
- CFX_ArrayTemplate<uint32_t> dwPageLenArray;
+ std::vector<uint32_t> 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 35fbdcb..cda0925 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_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 @@
uint32_t GetItemLength(int index, const std::vector<FX_FILESIZE>& 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 babefb8..d3cc6f3 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 718a1db..811618d 100644
--- a/testing/libfuzzer/BUILD.gn
+++ b/testing/libfuzzer/BUILD.gn
@@ -183,3 +183,18 @@
":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 0000000..d14d946
--- /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 <cstdint>
+
+#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<size_t>(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<const int32_t*>(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;
+}
