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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 attempts to decompress the fuzzed data with the simple
* decompression function to ensure the decompressor never crashes.
*/
#define ZSTD_STATIC_LINKING_ONLY
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include "fuzz_helpers.h"
#include "zstd.h"
#include "fuzz_data_producer.h"
static size_t const kBufSize = ZSTD_BLOCKSIZE_MAX;
static ZSTD_DStream *dstream = NULL;
static void* buf = NULL;
uint32_t seed;
static ZSTD_outBuffer makeOutBuffer(FUZZ_dataProducer_t *producer, uint32_t min)
{
ZSTD_outBuffer buffer = { buf, 0, 0 };
buffer.size = (FUZZ_dataProducer_uint32Range(producer, min, kBufSize));
FUZZ_ASSERT(buffer.size <= kBufSize);
if (buffer.size == 0) {
buffer.dst = NULL;
}
return buffer;
}
static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
FUZZ_dataProducer_t *producer,
uint32_t min)
{
ZSTD_inBuffer buffer = { *src, 0, 0 };
FUZZ_ASSERT(*size > 0);
buffer.size = (FUZZ_dataProducer_uint32Range(producer, min, *size));
FUZZ_ASSERT(buffer.size <= *size);
*src += buffer.size;
*size -= buffer.size;
if (buffer.size == 0) {
buffer.src = NULL;
}
return buffer;
}
int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
{
/* Give a random portion of src data to the producer, to use for
parameter generation. The rest will be used for (de)compression */
FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
/* Guarantee forward progress by refusing to generate 2 zero sized
* buffers in a row. */
int prevInWasZero = 0;
int prevOutWasZero = 0;
int stableOutBuffer;
ZSTD_outBuffer out;
size = FUZZ_dataProducer_reserveDataPrefix(producer);
/* Allocate all buffers and contexts if not already allocated */
if (!buf) {
buf = FUZZ_malloc(kBufSize);
}
if (!dstream) {
dstream = ZSTD_createDStream();
FUZZ_ASSERT(dstream);
} else {
FUZZ_ZASSERT(ZSTD_DCtx_reset(dstream, ZSTD_reset_session_only));
}
stableOutBuffer = FUZZ_dataProducer_uint32Range(producer, 0, 10) == 5;
if (stableOutBuffer) {
FUZZ_ZASSERT(ZSTD_DCtx_setParameter(dstream, ZSTD_d_stableOutBuffer, 1));
out.dst = buf;
out.size = kBufSize;
out.pos = 0;
}
while (size > 0) {
ZSTD_inBuffer in = makeInBuffer(&src, &size, producer, prevInWasZero ? 1 : 0);
prevInWasZero = in.size == 0;
while (in.pos != in.size) {
if (!stableOutBuffer || prevOutWasZero || FUZZ_dataProducer_uint32Range(producer, 0, 100) == 55) {
out = makeOutBuffer(producer, prevOutWasZero ? 1 : 0);
}
prevOutWasZero = out.size == 0;
size_t const rc = ZSTD_decompressStream(dstream, &out, &in);
if (ZSTD_isError(rc)) goto error;
}
}
error:
#ifndef STATEFUL_FUZZING
ZSTD_freeDStream(dstream); dstream = NULL;
#endif
FUZZ_dataProducer_free(producer);
return 0;
}
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