1 /*
2 * Copyright (c) Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11 /**
12 * This fuzz target performs a zstd round-trip test (compress & decompress),
13 * compares the result with the original, and calls abort() on corruption.
14 */
15
16 #define ZSTD_STATIC_LINKING_ONLY
17
18 #include <stddef.h>
19 #include <stdlib.h>
20 #include <stdio.h>
21 #include <string.h>
22 #include "fuzz_helpers.h"
23 #include "zstd_helpers.h"
24 #include "fuzz_data_producer.h"
25
26 ZSTD_CCtx *cctx = NULL;
27 static ZSTD_DCtx *dctx = NULL;
28 static uint8_t* cBuf = NULL;
29 static uint8_t* rBuf = NULL;
30 static size_t bufSize = 0;
31
makeOutBuffer(uint8_t * dst,size_t capacity,FUZZ_dataProducer_t * producer)32 static ZSTD_outBuffer makeOutBuffer(uint8_t *dst, size_t capacity,
33 FUZZ_dataProducer_t *producer)
34 {
35 ZSTD_outBuffer buffer = { dst, 0, 0 };
36
37 FUZZ_ASSERT(capacity > 0);
38 buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, capacity));
39 FUZZ_ASSERT(buffer.size <= capacity);
40
41 return buffer;
42 }
43
makeInBuffer(const uint8_t ** src,size_t * size,FUZZ_dataProducer_t * producer)44 static ZSTD_inBuffer makeInBuffer(const uint8_t **src, size_t *size,
45 FUZZ_dataProducer_t *producer)
46 {
47 ZSTD_inBuffer buffer = { *src, 0, 0 };
48
49 FUZZ_ASSERT(*size > 0);
50 buffer.size = (FUZZ_dataProducer_uint32Range(producer, 1, *size));
51 FUZZ_ASSERT(buffer.size <= *size);
52 *src += buffer.size;
53 *size -= buffer.size;
54
55 return buffer;
56 }
57
compress(uint8_t * dst,size_t capacity,const uint8_t * src,size_t srcSize,FUZZ_dataProducer_t * producer)58 static size_t compress(uint8_t *dst, size_t capacity,
59 const uint8_t *src, size_t srcSize,
60 FUZZ_dataProducer_t *producer)
61 {
62 size_t dstSize = 0;
63 ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
64 FUZZ_setRandomParameters(cctx, srcSize, producer);
65
66 while (srcSize > 0) {
67 ZSTD_inBuffer in = makeInBuffer(&src, &srcSize, producer);
68 /* Mode controls the action. If mode == -1 we pick a new mode */
69 int mode = -1;
70 while (in.pos < in.size || mode != -1) {
71 ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
72 /* Previous action finished, pick a new mode. */
73 if (mode == -1) mode = FUZZ_dataProducer_uint32Range(producer, 0, 9);
74 switch (mode) {
75 case 0: /* fall-through */
76 case 1: /* fall-through */
77 case 2: {
78 size_t const ret =
79 ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_flush);
80 FUZZ_ZASSERT(ret);
81 if (ret == 0)
82 mode = -1;
83 break;
84 }
85 case 3: {
86 size_t ret =
87 ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
88 FUZZ_ZASSERT(ret);
89 /* Reset the compressor when the frame is finished */
90 if (ret == 0) {
91 ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
92 if (FUZZ_dataProducer_uint32Range(producer, 0, 7) == 0) {
93 size_t const remaining = in.size - in.pos;
94 FUZZ_setRandomParameters(cctx, remaining, producer);
95 }
96 mode = -1;
97 }
98 break;
99 }
100 case 4: {
101 ZSTD_inBuffer nullIn = { NULL, 0, 0 };
102 ZSTD_outBuffer nullOut = { NULL, 0, 0 };
103 size_t const ret = ZSTD_compressStream2(cctx, &nullOut, &nullIn, ZSTD_e_continue);
104 FUZZ_ZASSERT(ret);
105 }
106 /* fall-through */
107 default: {
108 size_t const ret =
109 ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_continue);
110 FUZZ_ZASSERT(ret);
111 mode = -1;
112 }
113 }
114 dst += out.pos;
115 dstSize += out.pos;
116 capacity -= out.pos;
117 }
118 }
119 for (;;) {
120 ZSTD_inBuffer in = {NULL, 0, 0};
121 ZSTD_outBuffer out = makeOutBuffer(dst, capacity, producer);
122 size_t const ret = ZSTD_compressStream2(cctx, &out, &in, ZSTD_e_end);
123 FUZZ_ZASSERT(ret);
124
125 dst += out.pos;
126 dstSize += out.pos;
127 capacity -= out.pos;
128 if (ret == 0)
129 break;
130 }
131 return dstSize;
132 }
133
LLVMFuzzerTestOneInput(const uint8_t * src,size_t size)134 int LLVMFuzzerTestOneInput(const uint8_t *src, size_t size)
135 {
136 size_t neededBufSize;
137
138 /* Give a random portion of src data to the producer, to use for
139 parameter generation. The rest will be used for (de)compression */
140 FUZZ_dataProducer_t *producer = FUZZ_dataProducer_create(src, size);
141 size = FUZZ_dataProducer_reserveDataPrefix(producer);
142
143 neededBufSize = ZSTD_compressBound(size) * 15;
144
145 /* Allocate all buffers and contexts if not already allocated */
146 if (neededBufSize > bufSize) {
147 free(cBuf);
148 free(rBuf);
149 cBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
150 rBuf = (uint8_t*)FUZZ_malloc(neededBufSize);
151 bufSize = neededBufSize;
152 }
153 if (!cctx) {
154 cctx = ZSTD_createCCtx();
155 FUZZ_ASSERT(cctx);
156 }
157 if (!dctx) {
158 dctx = ZSTD_createDCtx();
159 FUZZ_ASSERT(dctx);
160 }
161
162 {
163 size_t const cSize = compress(cBuf, neededBufSize, src, size, producer);
164 size_t const rSize =
165 ZSTD_decompressDCtx(dctx, rBuf, neededBufSize, cBuf, cSize);
166 FUZZ_ZASSERT(rSize);
167 FUZZ_ASSERT_MSG(rSize == size, "Incorrect regenerated size");
168 FUZZ_ASSERT_MSG(!FUZZ_memcmp(src, rBuf, size), "Corruption!");
169 }
170
171 FUZZ_dataProducer_free(producer);
172 #ifndef STATEFUL_FUZZING
173 ZSTD_freeCCtx(cctx); cctx = NULL;
174 ZSTD_freeDCtx(dctx); dctx = NULL;
175 #endif
176 return 0;
177 }
178