You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
59 lines
2.0 KiB
59 lines
2.0 KiB
// Copyright 2017 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 <vector>
|
|
|
|
#include "core/fxcodec/gif/cfx_lzwdecompressor.h"
|
|
#include "third_party/base/numerics/safe_conversions.h"
|
|
|
|
// Between 2x and 5x is a standard range for LZW according to a quick
|
|
// search of papers. Running up to 10x to catch any niche cases.
|
|
constexpr uint32_t kMinCompressionRatio = 2;
|
|
constexpr uint32_t kMaxCompressionRatio = 10;
|
|
|
|
void LZWFuzz(const uint8_t* src_buf,
|
|
size_t src_size,
|
|
uint8_t color_exp,
|
|
uint8_t code_exp) {
|
|
std::unique_ptr<CFX_LZWDecompressor> decompressor =
|
|
CFX_LZWDecompressor::Create(color_exp, code_exp);
|
|
if (!decompressor)
|
|
return;
|
|
|
|
for (uint32_t compressions_ratio = kMinCompressionRatio;
|
|
compressions_ratio <= kMaxCompressionRatio; compressions_ratio++) {
|
|
std::vector<uint8_t> dest_buf(compressions_ratio * src_size);
|
|
// This cast should be safe since the caller is checking for overflow on
|
|
// the initial data.
|
|
uint32_t dest_size = static_cast<uint32_t>(dest_buf.size());
|
|
if (CFX_GifDecodeStatus::InsufficientDestSize !=
|
|
decompressor->Decode(src_buf, src_size, dest_buf.data(), &dest_size)) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
|
|
// Need at least 3 bytes to do anything.
|
|
if (size < 3)
|
|
return 0;
|
|
|
|
// Normally the GIF would provide the code and color sizes, instead, going
|
|
// to assume they are the first two bytes of data provided.
|
|
uint8_t color_exp = data[0];
|
|
uint8_t code_exp = data[1];
|
|
const uint8_t* lzw_data = data + 2;
|
|
uint32_t lzw_data_size = static_cast<uint32_t>(size - 2);
|
|
// Check that there isn't going to be an overflow in the destination buffer
|
|
// size.
|
|
if (lzw_data_size >
|
|
std::numeric_limits<uint32_t>::max() / kMaxCompressionRatio) {
|
|
return 0;
|
|
}
|
|
|
|
LZWFuzz(lzw_data, lzw_data_size, color_exp, code_exp);
|
|
|
|
return 0;
|
|
}
|