| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | * You may select, at your option, one of the above-listed licenses. |
| 9 | */ |
| 10 | |
| 11 | /** |
| 12 | * This fuzz target attempts to decompress the fuzzed data with the simple |
| 13 | * decompression function to ensure the decompressor never crashes. |
| 14 | */ |
| 15 | |
| 16 | #define ZSTD_STATIC_LINKING_ONLY |
| 17 | |
| 18 | #include <stddef.h> |
| 19 | #include <stdlib.h> |
| 20 | #include <stdio.h> |
| 21 | #include "fuzz_helpers.h" |
| 22 | #include "zstd.h" |
| 23 | #include "fuzz_data_producer.h" |
| 24 | |
| 25 | static ZSTD_DStream *dstream = NULL; |
| 26 | uint32_t seed; |
| 27 | |
| 28 | static ZSTD_outBuffer makeOutBuffer(FUZZ_dataProducer_t *producer, void* buf, size_t bufSize) |
| 29 | { |
| 30 | ZSTD_outBuffer buffer = { buf, 0, 0 }; |
| 31 | |
| 32 | if (FUZZ_dataProducer_empty(producer)) { |
| 33 | buffer.size = bufSize; |
| 34 | } else { |
| 35 | buffer.size = (FUZZ_dataProducer_uint32Range(producer, 0, bufSize)); |
| 36 | } |
| 37 | FUZZ_ASSERT(buffer.size <= bufSize); |
| 38 | |
| 39 | if (buffer.size == 0) { |
| 40 | buffer.dst = NULL; |
| 41 | } |
| 42 | |
| 43 | return buffer; |
| 44 | } |
| 45 | |
| 46 | static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size, |
| 47 | FUZZ_dataProducer_t *producer) |
| 48 | { |
| 49 | ZSTD_inBuffer buffer = { *src, 0, 0 }; |
| 50 | |
| 51 | FUZZ_ASSERT(*size > 0); |
| 52 | if (FUZZ_dataProducer_empty(producer)) { |
| 53 | buffer.size = *size; |
| 54 | } else { |
| 55 | buffer.size = (FUZZ_dataProducer_uint32Range(producer, 0, *size)); |
| 56 | } |
| 57 | FUZZ_ASSERT(buffer.size <= *size); |
| 58 | *src += buffer.size; |
| 59 | *size -= buffer.size; |
| 60 | |
| 61 | if (buffer.size == 0) { |
| 62 | buffer.src = NULL; |
| 63 | } |
| 64 | |
| 65 | return buffer; |
| 66 | } |
| 67 | |
| 68 | int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size) |
| 69 | { |
| 70 | /* Give a random portion of src data to the producer, to use for |
| 71 | parameter generation. The rest will be used for (de)compression */ |
| 72 | FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size); |
| 73 | int stableOutBuffer; |
| 74 | ZSTD_outBuffer out; |
| 75 | void* buf; |
| 76 | size_t bufSize; |
| 77 | size = FUZZ_dataProducer_reserveDataPrefix(producer); |
| 78 | bufSize = MAX(10 * size, ZSTD_BLOCKSIZE_MAX); |
| 79 | |
| 80 | /* Allocate all buffers and contexts if not already allocated */ |
| 81 | buf = FUZZ_malloc(bufSize); |
| 82 | |
| 83 | if (!dstream) { |
| 84 | dstream = ZSTD_createDStream(); |
| 85 | FUZZ_ASSERT(dstream); |
| 86 | } else { |
| 87 | FUZZ_ZASSERT(ZSTD_DCtx_reset(dstream, ZSTD_reset_session_only)); |
| 88 | } |
| 89 | |
| 90 | stableOutBuffer = FUZZ_dataProducer_uint32Range(producer, 0, 10) == 5; |
| 91 | if (stableOutBuffer) { |
| 92 | FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dstream, ZSTD_d_stableOutBuffer, 1)); |
| 93 | out.dst = buf; |
| 94 | out.size = bufSize; |
| 95 | out.pos = 0; |
| 96 | } else { |
| 97 | out = makeOutBuffer(producer, buf, bufSize); |
| 98 | } |
| 99 | |
| 100 | while (size > 0) { |
| 101 | ZSTD_inBuffer in = makeInBuffer(&src, &size, producer); |
| 102 | do { |
| 103 | size_t const rc = ZSTD_decompressStream(dstream, &out, &in); |
| 104 | if (ZSTD_isError(rc)) goto error; |
| 105 | if (out.pos == out.size) { |
| 106 | if (stableOutBuffer) goto error; |
| 107 | out = makeOutBuffer(producer, buf, bufSize); |
| 108 | } |
| 109 | } while (in.pos != in.size); |
| 110 | } |
| 111 | |
| 112 | error: |
| 113 | #ifndef STATEFUL_FUZZING |
| 114 | ZSTD_freeDStream(dstream); dstream = NULL; |
| 115 | #endif |
| 116 | FUZZ_dataProducer_free(producer); |
| 117 | free(buf); |
| 118 | return 0; |
| 119 | } |