1 /**
2 * This fuzz target attempts to decompress the fuzzed data with the simple
3 * decompression function to ensure the decompressor never crashes.
4 */
5
6 #include <stddef.h>
7 #include <stdint.h>
8 #include <stdlib.h>
9 #include <string.h>
10
11 #include "fuzz_helpers.h"
12 #include "fuzz_data_producer.h"
13 #include "lz4.h"
14
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)15 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
16 {
17 FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(data, size);
18 size_t const dstCapacitySeed = FUZZ_dataProducer_retrieve32(producer);
19 size = FUZZ_dataProducer_remainingBytes(producer);
20
21 size_t const dstCapacity = FUZZ_getRange_from_uint32(dstCapacitySeed, 0, 4 * size);
22 size_t const smallDictSize = size + 1;
23 size_t const largeDictSize = 64 * 1024 - 1;
24 size_t const dictSize = MAX(smallDictSize, largeDictSize);
25 char* const dst = (char*)malloc(dstCapacity);
26 char* const dict = (char*)malloc(dictSize + size);
27 char* const largeDict = dict;
28 char* const dataAfterDict = dict + dictSize;
29 char* const smallDict = dataAfterDict - smallDictSize;
30
31 FUZZ_ASSERT(dst);
32 FUZZ_ASSERT(dict);
33
34 /* Prepare the dictionary. The data doesn't matter for decompression. */
35 memset(dict, 0, dictSize);
36 memcpy(dataAfterDict, data, size);
37
38 /* Decompress using each possible dictionary configuration. */
39 /* No dictionary. */
40 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
41 dstCapacity, NULL, 0);
42 /* Small external dictonary. */
43 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
44 dstCapacity, smallDict, smallDictSize);
45 /* Large external dictionary. */
46 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
47 dstCapacity, largeDict, largeDictSize);
48 /* Small prefix. */
49 LZ4_decompress_safe_usingDict((char const*)dataAfterDict, dst, size,
50 dstCapacity, smallDict, smallDictSize);
51 /* Large prefix. */
52 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
53 dstCapacity, largeDict, largeDictSize);
54 /* Partial decompression. */
55 LZ4_decompress_safe_partial((char const*)data, dst, size,
56 dstCapacity, dstCapacity);
57 free(dst);
58 free(dict);
59 FUZZ_dataProducer_free(producer);
60
61 return 0;
62 }
63
