1 /* 2 * Copyright 2018 Google, LLC 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkBitmap.h" 9 #include "SkCodec.h" 10 #include "SkData.h" 11 FuzzIncrementalImageDecode(sk_sp<SkData> bytes)12bool FuzzIncrementalImageDecode(sk_sp<SkData> bytes) { 13 auto codec = SkCodec::MakeFromData(bytes); 14 if (!codec) { 15 return false; 16 } 17 18 SkBitmap bm; 19 if (!bm.tryAllocPixels(codec->getInfo())) { 20 // May fail in memory-constrained fuzzing environments 21 return false; 22 } 23 24 auto result = codec->startIncrementalDecode(bm.info(), bm.getPixels(), bm.rowBytes()); 25 if (result != SkCodec::kSuccess) { 26 return false; 27 } 28 29 // Deliberately uninitialized to verify that incrementalDecode initializes it when it 30 // returns kIncompleteInput or kErrorInInput. 31 int rowsDecoded; 32 result = codec->incrementalDecode(&rowsDecoded); 33 switch (result) { 34 case SkCodec::kIncompleteInput: 35 case SkCodec::kErrorInInput: 36 if (rowsDecoded < bm.height()) { 37 void* dst = SkTAddOffset<void>(bm.getPixels(), rowsDecoded * bm.rowBytes()); 38 sk_bzero(dst, (bm.height() - rowsDecoded) * bm.rowBytes()); 39 } 40 return true; // decoded a partial image 41 case SkCodec::kSuccess: 42 return true; 43 default: 44 return false; 45 } 46 } 47 48 #if defined(IS_FUZZING_WITH_LIBFUZZER) LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)49extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { 50 auto bytes = SkData::MakeWithoutCopy(data, size); 51 FuzzIncrementalImageDecode(bytes); 52 return 0; 53 } 54 #endif 55