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 "lz4.h"
13
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)14 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
15 {
16
17 uint32_t seed = FUZZ_seed(&data, &size);
18 size_t const dstCapacity = FUZZ_rand32(&seed, 0, 4 * size);
19 size_t const smallDictSize = size + 1;
20 size_t const largeDictSize = 64 * 1024 - 1;
21 size_t const dictSize = MAX(smallDictSize, largeDictSize);
22 char* const dst = (char*)malloc(dstCapacity);
23 char* const dict = (char*)malloc(dictSize + size);
24 char* const largeDict = dict;
25 char* const dataAfterDict = dict + dictSize;
26 char* const smallDict = dataAfterDict - smallDictSize;
27
28 FUZZ_ASSERT(dst);
29 FUZZ_ASSERT(dict);
30
31 /* Prepare the dictionary. The data doesn't matter for decompression. */
32 memset(dict, 0, dictSize);
33 memcpy(dataAfterDict, data, size);
34
35 /* Decompress using each possible dictionary configuration. */
36 /* No dictionary. */
37 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
38 dstCapacity, NULL, 0);
39 /* Small external dictonary. */
40 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
41 dstCapacity, smallDict, smallDictSize);
42 /* Large external dictionary. */
43 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
44 dstCapacity, largeDict, largeDictSize);
45 /* Small prefix. */
46 LZ4_decompress_safe_usingDict((char const*)dataAfterDict, dst, size,
47 dstCapacity, smallDict, smallDictSize);
48 /* Large prefix. */
49 LZ4_decompress_safe_usingDict((char const*)data, dst, size,
50 dstCapacity, largeDict, largeDictSize);
51 /* Partial decompression. */
52 LZ4_decompress_safe_partial((char const*)data, dst, size,
53 dstCapacity, dstCapacity);
54 free(dst);
55 free(dict);
56
57 return 0;
58 }
59