blob: 06bae03207358e885ca1490d6bee87f6e4cbea89 [file] [log] [blame]
// Copyright 2015 The Chromium 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 <stddef.h>
#include <stdint.h>
#include <vector>
#include "base/bind.h"
#include "base/callback_helpers.h"
#define PNG_INTERNAL
#include "third_party/libpng/png.h"
struct BufState {
const uint8_t* data;
size_t bytes_left;
};
void user_read_data(png_structp png_ptr, png_bytep data, png_size_t length) {
BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
if (length > buf_state->bytes_left) {
png_error(png_ptr, "read error");
}
memcpy(data, buf_state->data, length);
buf_state->bytes_left -= length;
buf_state->data += length;
}
static const int kPngHeaderSize = 8;
// Entry point for LibFuzzer.
// Roughly follows the libpng book example:
// http://www.libpng.org/pub/png/book/chapter13.html
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
if (size < kPngHeaderSize) {
return 0;
}
std::vector<unsigned char> v(data, data + size);
if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
// not a PNG.
return 0;
}
png_structp png_ptr = png_create_read_struct
(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
assert(png_ptr);
#ifdef MEMORY_SANITIZER
// To avoid OOM with MSan (crbug.com/648073). These values are recommended as
// safe settings by https://github.com/glennrp/libpng/blob/libpng16/pngusr.dfa
png_set_user_limits(png_ptr, 65535, 65535);
#endif
png_set_crc_action(png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
png_infop info_ptr = png_create_info_struct(png_ptr);
assert(info_ptr);
base::ScopedClosureRunner struct_deleter(base::Bind(
&png_destroy_read_struct, &png_ptr, &info_ptr, nullptr));
// Setting up reading from buffer.
std::unique_ptr<BufState> buf_state(new BufState());
buf_state->data = data + kPngHeaderSize;
buf_state->bytes_left = size - kPngHeaderSize;
png_set_read_fn(png_ptr, buf_state.get(), user_read_data);
png_set_sig_bytes(png_ptr, kPngHeaderSize);
// libpng error handling.
if (setjmp(png_jmpbuf(png_ptr))) {
return 0;
}
// Reading.
png_read_info(png_ptr, info_ptr);
png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
base::ScopedClosureRunner png_deleter(base::Bind(
&png_free, png_ptr, row));
// reset error handler to put png_deleter into scope.
if (setjmp(png_jmpbuf(png_ptr))) {
return 0;
}
png_uint_32 width, height;
int bit_depth, color_type, interlace_type, compression_type;
int filter_type;
if (!png_get_IHDR(png_ptr, info_ptr, &width, &height,
&bit_depth, &color_type, &interlace_type,
&compression_type, &filter_type)) {
return 0;
}
// This is going to be too slow.
if (width && height > 100000000 / width)
return 0;
int passes = png_set_interlace_handling(png_ptr);
png_start_read_image(png_ptr);
for (int pass = 0; pass < passes; ++pass) {
for (png_uint_32 y = 0; y < height; ++y) {
png_read_row(png_ptr, static_cast<png_bytep>(row), NULL);
}
}
return 0;
}