decompress_fuzzer.c File Reference

#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "fuzz_helpers.h"
#include "fuzz_data_producer.h"
#include "lz4.h"

Go to the source code of this file.

Functions
int	LLVMFuzzerTestOneInput (const uint8_t *data, size_t size)

Function Documentation

LLVMFuzzerTestOneInput()

int LLVMFuzzerTestOneInput	(	const uint8_t *	data,
		size_t	size
	)

This fuzz target attempts to decompress the fuzzed data with the simple decompression function to ensure the decompressor never crashes.

Definition at line 15 of file decompress_fuzzer.c.

{
    FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
    size_t const dstCapacitySeed = FUZZ_dataProducer_retrieve32(producer);
    size = FUZZ_dataProducer_remainingBytes(producer);
 
    size_t const dstCapacity = FUZZ_getRange_from_uint32(dstCapacitySeed, 0, 4 * size);
    size_t const smallDictSize = size + 1;
    size_t const largeDictSize = 64 * 1024 - 1;
    size_t const dictSize = MAX(smallDictSize, largeDictSize);
    char* const dst = (char*)malloc(dstCapacity);
    char* const dict = (char*)malloc(dictSize + size);
    char* const largeDict = dict;
    char* const dataAfterDict = dict + dictSize;
    char* const smallDict = dataAfterDict - smallDictSize;
 
    FUZZ_ASSERT(dst);
    FUZZ_ASSERT(dict);
 
    /* Prepare the dictionary. The data doesn't matter for decompression. */
    memset(dict, 0, dictSize);
    memcpy(dataAfterDict, data, size);
 
    /* Decompress using each possible dictionary configuration. */
    /* No dictionary. */
    LZ4_decompress_safe_usingDict((char const*)data, dst, size,
                                  dstCapacity, NULL, 0);
    /* Small external dictonary. */
    LZ4_decompress_safe_usingDict((char const*)data, dst, size,
                                  dstCapacity, smallDict, smallDictSize);
    /* Large external dictionary. */
    LZ4_decompress_safe_usingDict((char const*)data, dst, size,
                                  dstCapacity, largeDict, largeDictSize);
    /* Small prefix. */
    LZ4_decompress_safe_usingDict((char const*)dataAfterDict, dst, size,
                                  dstCapacity, smallDict, smallDictSize);
    /* Large prefix. */
    LZ4_decompress_safe_usingDict((char const*)data, dst, size,
                                  dstCapacity, largeDict, largeDictSize);
    /* Partial decompression. */
    LZ4_decompress_safe_partial((char const*)data, dst, size,
                                dstCapacity, dstCapacity);
    free(dst);
    free(dict);
    FUZZ_dataProducer_free(producer);
 
    return 0;
}

References dst, free(), FUZZ_ASSERT, FUZZ_dataProducer_create(), FUZZ_dataProducer_free(), FUZZ_dataProducer_remainingBytes(), FUZZ_dataProducer_retrieve32(), FUZZ_getRange_from_uint32(), LZ4_decompress_safe_partial(), LZ4_decompress_safe_usingDict(), malloc(), MAX, memcpy(), memset(), and NULL.