1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
///////////////////////////////////////////////////////////////////////////////
//
/// \file fuzz_encode_stream.c
/// \brief Fuzz test program for .xz encoding
//
// Authors: Maksym Vatsyk
// Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include "lzma.h"
#include "fuzz_common.h"
extern int
LLVMFuzzerTestOneInput(const uint8_t *inbuf, size_t inbuf_size)
{
if (inbuf_size == 0) {
fprintf(stderr, "no input data provided\n");
return 0;
}
// Set the LZMA options based on the first input byte. The fuzzer
// will learn through its mutational genetic algorithm with the
// code coverage feedback that the first byte must be one of the
// values with a switch case label. This allows us to have one fuzz
// target cover many critical code paths so the fuzz resources can
// be used efficiently.
uint32_t preset_level;
const uint8_t decider = inbuf[0];
switch (decider) {
case 0:
case 1:
case 5:
preset_level = (uint32_t)decider;
break;
case 6:
preset_level = 0 | LZMA_PRESET_EXTREME;
break;
case 7:
preset_level = 3 | LZMA_PRESET_EXTREME;
break;
default:
return 0;
}
// Initialize lzma_options with the above preset level
lzma_options_lzma opt_lzma;
if (lzma_lzma_preset(&opt_lzma, preset_level)){
fprintf(stderr, "lzma_lzma_preset() failed\n");
abort();
}
// Set the filter chain as only LZMA2.
lzma_filter filters[2] = {
{
.id = LZMA_FILTER_LZMA2,
.options = &opt_lzma,
}, {
.id = LZMA_VLI_UNKNOWN,
}
};
// initialize empty LZMA stream
lzma_stream strm = LZMA_STREAM_INIT;
// Initialize the stream encoder using the above
// stream, filter chain and CRC64.
lzma_ret ret = lzma_stream_encoder(&strm, filters, LZMA_CHECK_CRC64);
if (ret != LZMA_OK) {
fprintf(stderr, "lzma_stream_encoder() failed (%d)\n", ret);
abort();
}
fuzz_code(&strm, inbuf + 1, inbuf_size - 1);
// Free the allocated memory.
lzma_end(&strm);
return 0;
}
|
