5717bd39ee
When the output buffer is `NULL` with size 0, but the frame content size is non-zero, we will write to the NULL pointer because our bounds check underflowed. This was exposed by a recent PR that allowed an empty frame into the single-pass shortcut in streaming mode. * Fix the bug. * Fix another NULL dereference in zstd-v1. * Overflow checks in 32-bit mode. * Add a dedicated test. * Expose the bug in the dedicated simple_decompress fuzzer. * Switch all mallocs in fuzzers to return NULL for size=0. * Fix a new timeout in a fuzzer. Neither clang nor gcc show a decompression speed regression on x86-64. On x86-32 clang is slightly positive and gcc loses 2.5% of speed. Credit to OSS-Fuzz.
104 lines
3.7 KiB
C
104 lines
3.7 KiB
C
/*
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* Copyright (c) 2016-2020, Facebook, Inc.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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/**
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* This fuzz target makes sure that whenever a compression dictionary can be
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* loaded, the data can be round tripped.
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*/
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#include <stddef.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "fuzz_helpers.h"
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#include "zstd_helpers.h"
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#include "fuzz_data_producer.h"
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/**
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* Compresses the data and returns the compressed size or an error.
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*/
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static size_t compress(void* compressed, size_t compressedCapacity,
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void const* source, size_t sourceSize,
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void const* dict, size_t dictSize,
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ZSTD_dictLoadMethod_e dictLoadMethod,
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ZSTD_dictContentType_e dictContentType,
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int const refPrefix)
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{
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ZSTD_CCtx* cctx = ZSTD_createCCtx();
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if (refPrefix)
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FUZZ_ZASSERT(ZSTD_CCtx_refPrefix_advanced(
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cctx, dict, dictSize, dictContentType));
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else
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FUZZ_ZASSERT(ZSTD_CCtx_loadDictionary_advanced(
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cctx, dict, dictSize, dictLoadMethod, dictContentType));
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size_t const compressedSize = ZSTD_compress2(
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cctx, compressed, compressedCapacity, source, sourceSize);
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ZSTD_freeCCtx(cctx);
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return compressedSize;
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}
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static size_t decompress(void* result, size_t resultCapacity,
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void const* compressed, size_t compressedSize,
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void const* dict, size_t dictSize,
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ZSTD_dictLoadMethod_e dictLoadMethod,
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ZSTD_dictContentType_e dictContentType,
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int const refPrefix)
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{
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ZSTD_DCtx* dctx = ZSTD_createDCtx();
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if (refPrefix)
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FUZZ_ZASSERT(ZSTD_DCtx_refPrefix_advanced(
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dctx, dict, dictSize, dictContentType));
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else
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FUZZ_ZASSERT(ZSTD_DCtx_loadDictionary_advanced(
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dctx, dict, dictSize, dictLoadMethod, dictContentType));
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size_t const resultSize = ZSTD_decompressDCtx(
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dctx, result, resultCapacity, compressed, compressedSize);
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FUZZ_ZASSERT(resultSize);
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ZSTD_freeDCtx(dctx);
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return resultSize;
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}
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int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
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{
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FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
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int const refPrefix = FUZZ_dataProducer_uint32Range(producer, 0, 1) != 0;
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ZSTD_dictLoadMethod_e const dlm =
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size = FUZZ_dataProducer_uint32Range(producer, 0, 1);
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ZSTD_dictContentType_e const dct =
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FUZZ_dataProducer_uint32Range(producer, 0, 2);
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size = FUZZ_dataProducer_remainingBytes(producer);
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DEBUGLOG(2, "Dict load method %d", dlm);
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DEBUGLOG(2, "Dict content type %d", dct);
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DEBUGLOG(2, "Dict size %u", (unsigned)size);
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void* const rBuf = FUZZ_malloc(size);
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size_t const cBufSize = ZSTD_compressBound(size);
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void* const cBuf = FUZZ_malloc(cBufSize);
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size_t const cSize =
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compress(cBuf, cBufSize, src, size, src, size, dlm, dct, refPrefix);
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/* compression failing is okay */
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if (ZSTD_isError(cSize)) {
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FUZZ_ASSERT_MSG(dct != ZSTD_dct_rawContent, "Raw must always succeed!");
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goto out;
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}
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size_t const rSize =
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decompress(rBuf, size, cBuf, cSize, src, size, dlm, dct, refPrefix);
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FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
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FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
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out:
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free(cBuf);
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free(rBuf);
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FUZZ_dataProducer_free(producer);
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return 0;
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}
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