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Implement new fuzzer for sequence compression

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senhuang42
2020-11-16 10:54:19 -05:00
parent c5fbd55dac
commit ed575963c5
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tests/fuzz/sequence_compression_api.c Normal file
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/*
* Copyright (c) 2016-2020, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/
/**
* This fuzz target performs a zstd round-trip test (compress & decompress),
* compares the result with the original, and calls abort() on corruption.
*/
#define ZSTD_STATIC_LINKING_ONLY
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "fuzz_helpers.h"
#include "zstd_helpers.h"
#include "fuzz_data_producer.h"
static ZSTD_CCtx *cctx = NULL;
static ZSTD_DCtx *dctx = NULL;
#define ZSTD_FUZZ_GENERATED_SRC_MAXSIZE (1 << 25) /* Allow up to 32MB generated data */
#define ZSTD_FUZZ_MATCHLENGTH_MAXSIZE (1 << 18) /* Allow up to 256KB matches */
#define ZSTD_FUZZ_GENERATED_LITERALS_MAXSIZE (1 << 19) /* Allow up to 512KB literals buffer */
#define ZSTD_FUZZ_GENERATED_DICT_MAXSIZE (1 << 18) /* Allow up to a 256KB dict */
#define ZSTD_FUZZ_GENERATE_REPCODES 0 /* Disabled repcode fuzzing for now */
/* Make a pseudorandom string - this simple function exists to avoid
* taking a dependency on datagen.h to have RDG_genBuffer(). We don't need anything fancy.
*/
static char *generatePseudoRandomString(char *str, size_t size) {
const char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJK1234567890!@#$^&*()_";
if (size) {
--size;
for (size_t n = 0; n < size; n++) {
int key = rand() % (int) (sizeof charset - 1);
str[n] = charset[key];
}
}
return str;
}
/* Returns size of source buffer */
static size_t decodeSequences(void* dst, const ZSTD_Sequence* generatedSequences, size_t nbSequences,
const void* literals, size_t literalsSize, const void* dict, size_t dictSize) {
const uint8_t* ip = literals;
const uint8_t* dictPtr = dict;
uint8_t* op = dst;
size_t generatedSrcBufferSize = 0;
size_t bytesWritten = 0;
/* Note that src is a literals buffer */
for (size_t i = 0; i < nbSequences; ++i) {
assert(generatedSequences[i].matchLength != 0);
assert(generatedSequences[i].offset != 0);
ZSTD_memcpy(op, ip, generatedSequences[i].litLength);
bytesWritten += generatedSequences[i].litLength;
op += generatedSequences[i].litLength;
ip += generatedSequences[i].litLength;
literalsSize -= generatedSequences[i].litLength;
assert(generatedSequences[i].offset != 0);
/* Copy over the match */
{ size_t matchLength = generatedSequences[i].matchLength;
size_t j = 0;
size_t k = 0;
if (dictSize != 0) {
if (generatedSequences[i].offset > bytesWritten) {
/* Offset goes into the dictionary */
size_t offsetFromEndOfDict = generatedSequences[i].offset - bytesWritten;
for (; k < offsetFromEndOfDict && k < matchLength; ++k) {
op[k] = dictPtr[dictSize - offsetFromEndOfDict + k];
}
matchLength -= k;
op += k;
}
}
for (; j < matchLength; ++j) {
op[j] = op[j-(int)generatedSequences[i].offset];
}
op += j;
assert(generatedSequences[i].matchLength == j + k);
bytesWritten += generatedSequences[i].matchLength;
}
}
generatedSrcBufferSize = bytesWritten;
assert(ip <= literals + literalsSize);
ZSTD_memcpy(op, ip, literalsSize);
return generatedSrcBufferSize;
}
/* Returns nb sequences generated
* TODO: Add repcode fuzzing once we support repcode match splits
*/
static size_t generateRandomSequences(ZSTD_Sequence* generatedSequences, FUZZ_dataProducer_t* producer,
size_t literalsSize, size_t dictSize,
size_t windowLog) {
uint32_t bytesGenerated = 0;
uint32_t nbSeqGenerated = 0;
uint32_t litLength;
uint32_t matchLength;
uint32_t offset;
uint32_t offsetBound;
uint32_t repCode = 0;
uint32_t isFirstSequence = 1;
uint32_t windowSize = 1 << windowLog;
while (bytesGenerated < ZSTD_FUZZ_GENERATED_SRC_MAXSIZE && !FUZZ_dataProducer_empty(producer)) {
litLength = isFirstSequence ? FUZZ_dataProducer_uint32Range(producer, 1, literalsSize)
: FUZZ_dataProducer_uint32Range(producer, 0, literalsSize);
literalsSize -= litLength;
bytesGenerated += litLength;
if (bytesGenerated > ZSTD_FUZZ_GENERATED_SRC_MAXSIZE) {
break;
}
offsetBound = bytesGenerated > windowSize ? windowSize : bytesGenerated + dictSize;
offset = FUZZ_dataProducer_uint32Range(producer, 1, offsetBound);
matchLength = FUZZ_dataProducer_uint32Range(producer, ZSTD_MINMATCH_MIN, ZSTD_FUZZ_MATCHLENGTH_MAXSIZE);
bytesGenerated += matchLength;
if (bytesGenerated > ZSTD_FUZZ_GENERATED_SRC_MAXSIZE) {
break;
}
ZSTD_Sequence seq = {offset, litLength, matchLength, repCode};
generatedSequences[nbSeqGenerated++] = seq;
isFirstSequence = 0;
}
return nbSeqGenerated;
}
static size_t roundTripTest(void *result, size_t resultCapacity,
void *compressed, size_t compressedCapacity,
const void *src, size_t srcSize,
const void *dict, size_t dictSize,
const ZSTD_Sequence* generatedSequences, size_t generatedSequencesSize,
size_t wLog, unsigned cLevel, unsigned hasDict)
{
size_t cSize;
size_t dSize;
ZSTD_CDict* cdict = NULL;
ZSTD_DDict* ddict = NULL;
ZSTD_CCtx_reset(cctx, ZSTD_reset_session_and_parameters);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_nbWorkers, 0);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_compressionLevel, cLevel);
ZSTD_CCtx_setParameter(cctx, ZSTD_c_windowLog, wLog);
/* TODO: Add block delim mode fuzzing */
ZSTD_CCtx_setParameter(cctx, ZSTD_c_blockDelimiters, ZSTD_sf_noBlockDelimiters);
if (hasDict) {
cdict = ZSTD_createCDict(dict, dictSize, cLevel);
FUZZ_ASSERT(cdict);
ZSTD_CCtx_refCDict(cctx, cdict);
ddict = ZSTD_createDDict(dict, dictSize);
FUZZ_ASSERT(ddict);
ZSTD_DCtx_refDDict(dctx, ddict);
}
cSize = ZSTD_compressSequences(cctx, compressed, compressedCapacity,
generatedSequences, generatedSequencesSize,
src, srcSize);
FUZZ_ZASSERT(cSize);
dSize = ZSTD_decompressDCtx(dctx, result, resultCapacity, compressed, cSize);
FUZZ_ZASSERT(dSize);
if (cdict) {
ZSTD_freeCDict(cdict);
}
if (ddict) {
ZSTD_freeDDict(ddict);
}
return dSize;
}
int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
{
void* rBuf;
size_t rBufSize;
void* cBuf;
size_t cBufSize;
void* generatedSrc;
size_t generatedSrcSize;
ZSTD_Sequence* generatedSequences;
size_t nbSequences;
void* literalsBuffer;
size_t literalsSize;
void* dictBuffer;
size_t dictSize = 0;
unsigned hasDict;
unsigned wLog;
int cLevel;
FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
literalsSize = FUZZ_dataProducer_uint32Range(producer, 1, ZSTD_FUZZ_GENERATED_LITERALS_MAXSIZE);
literalsBuffer = FUZZ_malloc(literalsSize);
literalsBuffer = generatePseudoRandomString(literalsBuffer, literalsSize);
hasDict = FUZZ_dataProducer_uint32Range(producer, 0, 1);
if (hasDict) {
dictSize = FUZZ_dataProducer_uint32Range(producer, 1, ZSTD_FUZZ_GENERATED_DICT_MAXSIZE);
dictBuffer = FUZZ_malloc(dictSize);
dictBuffer = generatePseudoRandomString(dictBuffer, dictSize);
}
// Generate window log first so we dont generate offsets too large
wLog = FUZZ_dataProducer_uint32Range(producer, ZSTD_WINDOWLOG_MIN, ZSTD_WINDOWLOG_MAX);
cLevel = FUZZ_dataProducer_int32Range(producer, (int)ZSTD_minCLevel, (int)ZSTD_maxCLevel);
generatedSequences = FUZZ_malloc(sizeof(ZSTD_Sequence)*ZSTD_FUZZ_GENERATED_SRC_MAXSIZE);
generatedSrc = FUZZ_malloc(ZSTD_FUZZ_GENERATED_SRC_MAXSIZE);
nbSequences = generateRandomSequences(generatedSequences, producer, literalsSize, dictSize, wLog);
generatedSrcSize = decodeSequences(generatedSrc, generatedSequences, nbSequences, literalsBuffer, literalsSize, dictBuffer, dictSize);
cBufSize = ZSTD_compressBound(generatedSrcSize);
cBuf = FUZZ_malloc(cBufSize);
rBufSize = generatedSrcSize;
rBuf = FUZZ_malloc(rBufSize);
if (!cctx) {
cctx = ZSTD_createCCtx();
FUZZ_ASSERT(cctx);
}
if (!dctx) {
dctx = ZSTD_createDCtx();
FUZZ_ASSERT(dctx);
}
size_t const result = roundTripTest(rBuf, rBufSize,
cBuf, cBufSize,
generatedSrc, generatedSrcSize,
dictBuffer, dictSize,
generatedSequences, nbSequences,
wLog, cLevel, hasDict);
FUZZ_ZASSERT(result);
FUZZ_ASSERT_MSG(result == generatedSrcSize, "Incorrect regenerated size");
FUZZ_ASSERT_MSG(!FUZZ_memcmp(generatedSrc, rBuf, generatedSrcSize), "Corruption!");
free(rBuf);
free(cBuf);
free(generatedSequences);
free(generatedSrc);
free(literalsBuffer);
FUZZ_dataProducer_free(producer);
#ifndef STATEFUL_FUZZING
ZSTD_freeCCtx(cctx); cctx = NULL;
ZSTD_freeDCtx(dctx); dctx = NULL;
#endif
return 0;
}