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Diffstat (limited to 'tests/fuzzer/huffman_fuzzer.c')
-rw-r--r-- | tests/fuzzer/huffman_fuzzer.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/tests/fuzzer/huffman_fuzzer.c b/tests/fuzzer/huffman_fuzzer.c new file mode 100644 index 00000000..03e1fdc4 --- /dev/null +++ b/tests/fuzzer/huffman_fuzzer.c @@ -0,0 +1,65 @@ +// Copyright 2023 Google Inc. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +//////////////////////////////////////////////////////////////////////////////// + +#include <stdint.h> +#include <string.h> + +#include "src/dec/vp8li_dec.h" +#include "src/utils/bit_reader_utils.h" +#include "src/utils/huffman_utils.h" +#include "src/utils/utils.h" +#include "src/webp/format_constants.h" + +int LLVMFuzzerTestOneInput(const uint8_t* const data, size_t size) { + // Number of bits to initialize data. + static const int kColorCacheBitsBits = 4; + // 'num_htree_groups' is contained in the RG channel, hence 16 bits. + static const int kNumHtreeGroupsBits = 16; + if (size * sizeof(*data) < kColorCacheBitsBits + kNumHtreeGroupsBits) { + return 0; + } + + // A non-NULL mapping brings minor changes that are tested by the normal + // fuzzer. + int* const mapping = NULL; + HuffmanTables huffman_tables; + memset(&huffman_tables, 0, sizeof(huffman_tables)); + HTreeGroup* htree_groups = NULL; + + VP8LDecoder* dec = VP8LNew(); + if (dec == NULL) goto Error; + VP8LBitReader* const br = &dec->br_; + VP8LInitBitReader(br, data, size); + + const int color_cache_bits = VP8LReadBits(br, kColorCacheBitsBits); + if (color_cache_bits < 1 || color_cache_bits > MAX_CACHE_BITS) goto Error; + + const int num_htree_groups = VP8LReadBits(br, kNumHtreeGroupsBits); + // 'num_htree_groups' cannot be 0 as it is built from a non-empty image. + if (num_htree_groups == 0) goto Error; + // This variable is only useful when mapping is not NULL. + const int num_htree_groups_max = num_htree_groups; + (void)ReadHuffmanCodesHelper(color_cache_bits, num_htree_groups, + num_htree_groups_max, mapping, dec, + &huffman_tables, &htree_groups); + + Error: + WebPSafeFree(mapping); + VP8LHtreeGroupsFree(htree_groups); + VP8LHuffmanTablesDeallocate(&huffman_tables); + VP8LDelete(dec); + return 0; +} |