2 // libpng_read_fuzzer.cc
3 // Copyright 2017-2018 Glenn Randers-Pehrson
4 // Copyright 2015 The Chromium Authors. All rights reserved.
5 // Use of this source code is governed by a BSD-style license that may
6 // be found in the LICENSE file https://cs.chromium.org/chromium/src/LICENSE
8 // Last changed in libpng 1.6.35 [July 15, 2018]
10 // The modifications in 2017 by Glenn Randers-Pehrson include
11 // 1. addition of a PNG_CLEANUP macro,
12 // 2. setting the option to ignore ADLER32 checksums,
13 // 3. adding "#include <string.h>" which is needed on some platforms
14 // to provide memcpy().
15 // 4. adding read_end_info() and creating an end_info structure.
16 // 5. adding calls to png_set_*() transforms commonly used by browsers.
28 if(png_handler.png_ptr) \
30 if (png_handler.row_ptr) \
31 png_free(png_handler.png_ptr, png_handler.row_ptr); \
32 if (png_handler.end_info_ptr) \
33 png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
34 &png_handler.end_info_ptr); \
35 else if (png_handler.info_ptr) \
36 png_destroy_read_struct(&png_handler.png_ptr, &png_handler.info_ptr,\
39 png_destroy_read_struct(&png_handler.png_ptr, nullptr, nullptr); \
40 png_handler.png_ptr = nullptr; \
41 png_handler.row_ptr = nullptr; \
42 png_handler.info_ptr = nullptr; \
43 png_handler.end_info_ptr = nullptr; \
51 struct PngObjectHandler {
52 png_infop info_ptr = nullptr;
53 png_structp png_ptr = nullptr;
54 png_infop end_info_ptr = nullptr;
55 png_voidp row_ptr = nullptr;
56 BufState* buf_state = nullptr;
60 png_free(png_ptr, row_ptr);
62 png_destroy_read_struct(&png_ptr, &info_ptr, &end_info_ptr);
64 png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
66 png_destroy_read_struct(&png_ptr, nullptr, nullptr);
71 void user_read_data(png_structp png_ptr, png_bytep data, size_t length) {
72 BufState* buf_state = static_cast<BufState*>(png_get_io_ptr(png_ptr));
73 if (length > buf_state->bytes_left) {
74 png_error(png_ptr, "read error");
76 memcpy(data, buf_state->data, length);
77 buf_state->bytes_left -= length;
78 buf_state->data += length;
81 static const int kPngHeaderSize = 8;
83 // Entry point for LibFuzzer.
84 // Roughly follows the libpng book example:
85 // http://www.libpng.org/pub/png/book/chapter13.html
86 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
87 if (size < kPngHeaderSize) {
91 std::vector<unsigned char> v(data, data + size);
92 if (png_sig_cmp(v.data(), 0, kPngHeaderSize)) {
97 PngObjectHandler png_handler;
98 png_handler.png_ptr = nullptr;
99 png_handler.row_ptr = nullptr;
100 png_handler.info_ptr = nullptr;
101 png_handler.end_info_ptr = nullptr;
103 png_handler.png_ptr = png_create_read_struct
104 (PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
105 if (!png_handler.png_ptr) {
109 png_handler.info_ptr = png_create_info_struct(png_handler.png_ptr);
110 if (!png_handler.info_ptr) {
115 png_handler.end_info_ptr = png_create_info_struct(png_handler.png_ptr);
116 if (!png_handler.end_info_ptr) {
121 png_set_crc_action(png_handler.png_ptr, PNG_CRC_QUIET_USE, PNG_CRC_QUIET_USE);
122 #ifdef PNG_IGNORE_ADLER32
123 png_set_option(png_handler.png_ptr, PNG_IGNORE_ADLER32, PNG_OPTION_ON);
126 // Setting up reading from buffer.
127 png_handler.buf_state = new BufState();
128 png_handler.buf_state->data = data + kPngHeaderSize;
129 png_handler.buf_state->bytes_left = size - kPngHeaderSize;
130 png_set_read_fn(png_handler.png_ptr, png_handler.buf_state, user_read_data);
131 png_set_sig_bytes(png_handler.png_ptr, kPngHeaderSize);
133 if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
139 png_read_info(png_handler.png_ptr, png_handler.info_ptr);
141 // reset error handler to put png_deleter into scope.
142 if (setjmp(png_jmpbuf(png_handler.png_ptr))) {
147 png_uint_32 width, height;
148 int bit_depth, color_type, interlace_type, compression_type;
151 if (!png_get_IHDR(png_handler.png_ptr, png_handler.info_ptr, &width,
152 &height, &bit_depth, &color_type, &interlace_type,
153 &compression_type, &filter_type)) {
158 // This is going to be too slow.
159 if (width && height > 100000000 / width) {
164 // Set several transforms that browsers typically use:
165 png_set_gray_to_rgb(png_handler.png_ptr);
166 png_set_expand(png_handler.png_ptr);
167 png_set_packing(png_handler.png_ptr);
168 png_set_scale_16(png_handler.png_ptr);
169 png_set_tRNS_to_alpha(png_handler.png_ptr);
171 int passes = png_set_interlace_handling(png_handler.png_ptr);
173 png_read_update_info(png_handler.png_ptr, png_handler.info_ptr);
175 png_handler.row_ptr = png_malloc(
176 png_handler.png_ptr, png_get_rowbytes(png_handler.png_ptr,
177 png_handler.info_ptr));
179 for (int pass = 0; pass < passes; ++pass) {
180 for (png_uint_32 y = 0; y < height; ++y) {
181 png_read_row(png_handler.png_ptr,
182 static_cast<png_bytep>(png_handler.row_ptr), nullptr);
186 png_read_end(png_handler.png_ptr, png_handler.end_info_ptr);