simple_compress.c

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * 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 compress the fuzzed data with the simple
 * compression function with an output buffer that may be too small to
 * ensure that the compressor never crashes.
 */

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include "fuzz_helpers.h"
#include "zstd.h"
#include "zstd_errors.h"
#include "zstd_helpers.h"
#include "fuzz_data_producer.h"
#include "fuzz_third_party_seq_prod.h"

static ZSTD_CCtx *cctx = NULL;

int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
{
    FUZZ_SEQ_PROD_SETUP();

    /* 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);
    size = FUZZ_dataProducer_reserveDataPrefix(producer);

    size_t const maxSize = ZSTD_compressBound(size);
    size_t const bufSize = FUZZ_dataProducer_uint32Range(producer, 0, maxSize);

    int const cLevel = FUZZ_dataProducer_int32Range(producer, kMinClevel, kMaxClevel);

    if (!cctx) {
        cctx = ZSTD_createCCtx();
        FUZZ_ASSERT(cctx);
    }

    void *rBuf = FUZZ_malloc(bufSize);
    size_t const ret = ZSTD_compressCCtx(cctx, rBuf, bufSize, src, size, cLevel);
    if (ZSTD_isError(ret)) {
        FUZZ_ASSERT(ZSTD_getErrorCode(ret) == ZSTD_error_dstSize_tooSmall);
    }
    free(rBuf);
    FUZZ_dataProducer_free(producer);
#ifndef STATEFUL_FUZZING
    ZSTD_freeCCtx(cctx); cctx = NULL;
#endif
    FUZZ_SEQ_PROD_TEARDOWN();
    return 0;
}