1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #define FUZZ_LOG_TAG "main"
17
18 #include "binder.h"
19 #include "binder_ndk.h"
20 #include "hwbinder.h"
21 #include "util.h"
22
23 #include <iostream>
24
25 #include <android-base/hex.h>
26 #include <android-base/logging.h>
27 #include <android/binder_auto_utils.h>
28 #include <android/binder_libbinder.h>
29 #include <fuzzbinder/random_parcel.h>
30 #include <fuzzer/FuzzedDataProvider.h>
31
32 #include <cstdlib>
33 #include <ctime>
34 #include <sys/resource.h>
35 #include <sys/time.h>
36
37 using android::fillRandomParcel;
38 using android::RandomParcelOptions;
39 using android::sp;
40 using android::base::HexString;
41
fillRandomParcel(::android::hardware::Parcel * p,FuzzedDataProvider && provider,RandomParcelOptions * options)42 void fillRandomParcel(::android::hardware::Parcel* p, FuzzedDataProvider&& provider,
43 RandomParcelOptions* options) {
44 // TODO: functionality to create random parcels for libhwbinder parcels
45 (void)options;
46
47 std::vector<uint8_t> input = provider.ConsumeRemainingBytes<uint8_t>();
48 p->setData(input.data(), input.size());
49 }
fillRandomParcel(NdkParcelAdapter * p,FuzzedDataProvider && provider,RandomParcelOptions * options)50 static void fillRandomParcel(NdkParcelAdapter* p, FuzzedDataProvider&& provider,
51 RandomParcelOptions* options) {
52 // fill underlying parcel using functions to fill random libbinder parcel
53 fillRandomParcel(p->parcel(), std::move(provider), options);
54 }
55
56 template <typename P, typename B>
doTransactFuzz(const char * backend,const sp<B> & binder,FuzzedDataProvider && provider)57 void doTransactFuzz(const char* backend, const sp<B>& binder, FuzzedDataProvider&& provider) {
58 uint32_t code = provider.ConsumeIntegral<uint32_t>();
59 uint32_t flag = provider.ConsumeIntegral<uint32_t>();
60
61 FUZZ_LOG() << "backend: " << backend;
62
63 RandomParcelOptions options;
64
65 P reply;
66 P data;
67 fillRandomParcel(&data, std::move(provider), &options);
68 (void)binder->transact(code, data, &reply, flag);
69 }
70
71 template <typename P>
doReadFuzz(const char * backend,const std::vector<ParcelRead<P>> & reads,FuzzedDataProvider && provider)72 void doReadFuzz(const char* backend, const std::vector<ParcelRead<P>>& reads,
73 FuzzedDataProvider&& provider) {
74 // Allow some majority of the bytes to be dedicated to telling us what to
75 // do. The fixed value added here represents that we want to test doing a
76 // lot of 'instructions' even on really short parcels.
77 size_t maxInstructions = 20 + (provider.remaining_bytes() * 2 / 3);
78 // but don't always use that many instructions. We want to allow the fuzzer
79 // to explore large parcels with few instructions if it wants to.
80 std::vector<uint8_t> instructions = provider.ConsumeBytes<uint8_t>(
81 provider.ConsumeIntegralInRange<size_t>(0, maxInstructions));
82
83 RandomParcelOptions options;
84
85 P p;
86 fillRandomParcel(&p, std::move(provider), &options);
87
88 // since we are only using a byte to index
89 CHECK(reads.size() <= 255) << reads.size();
90
91 FUZZ_LOG() << "backend: " << backend;
92 FUZZ_LOG() << "input: " << HexString(p.data(), p.dataSize());
93 FUZZ_LOG() << "instructions: " << HexString(instructions.data(), instructions.size());
94
95 FuzzedDataProvider instructionsProvider(instructions.data(), instructions.size());
96 while (instructionsProvider.remaining_bytes() > 0) {
97 uint8_t idx = instructionsProvider.ConsumeIntegralInRange<uint8_t>(0, reads.size() - 1);
98
99 FUZZ_LOG() << "Instruction " << idx << " avail: " << p.dataAvail()
100 << " pos: " << p.dataPosition() << " cap: " << p.dataCapacity();
101
102 reads[idx](p, instructionsProvider);
103 }
104 }
105
106 // Append two random parcels.
107 template <typename P>
doAppendFuzz(const char * backend,FuzzedDataProvider && provider)108 void doAppendFuzz(const char* backend, FuzzedDataProvider&& provider) {
109 int32_t start = provider.ConsumeIntegral<int32_t>();
110 int32_t len = provider.ConsumeIntegral<int32_t>();
111
112 std::vector<uint8_t> bytes = provider.ConsumeBytes<uint8_t>(
113 provider.ConsumeIntegralInRange<size_t>(0, provider.remaining_bytes()));
114
115 // same options so that FDs and binders could be shared in both Parcels
116 RandomParcelOptions options;
117
118 P p0, p1;
119 fillRandomParcel(&p0, FuzzedDataProvider(bytes.data(), bytes.size()), &options);
120 fillRandomParcel(&p1, std::move(provider), &options);
121
122 FUZZ_LOG() << "backend: " << backend;
123 FUZZ_LOG() << "start: " << start << " len: " << len;
124
125 p0.appendFrom(&p1, start, len);
126 }
127
NothingClass_onCreate(void * args)128 void* NothingClass_onCreate(void* args) {
129 return args;
130 }
NothingClass_onDestroy(void *)131 void NothingClass_onDestroy(void* /*userData*/) {}
NothingClass_onTransact(AIBinder *,transaction_code_t,const AParcel *,AParcel *)132 binder_status_t NothingClass_onTransact(AIBinder*, transaction_code_t, const AParcel*, AParcel*) {
133 return STATUS_UNKNOWN_ERROR;
134 }
135 static AIBinder_Class* kNothingClass =
136 AIBinder_Class_define("nothing", NothingClass_onCreate, NothingClass_onDestroy,
137 NothingClass_onTransact);
138
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)139 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
140 if (size <= 1) return 0; // no use
141
142 // avoid timeouts, see b/142617274, b/142473153
143 if (size > 50000) return 0;
144
145 FuzzedDataProvider provider = FuzzedDataProvider(data, size);
146
147 const std::function<void(FuzzedDataProvider &&)> fuzzBackend[] = {
148 [](FuzzedDataProvider&& provider) {
149 doTransactFuzz<
150 ::android::hardware::Parcel>("hwbinder",
151 sp<::android::hardware::BHwBinder>::make(),
152 std::move(provider));
153 },
154 [](FuzzedDataProvider&& provider) {
155 doTransactFuzz<::android::Parcel>("binder", sp<::android::BBinder>::make(),
156 std::move(provider));
157 },
158 [](FuzzedDataProvider&& provider) {
159 // fuzz from the libbinder layer since it's a superset of the
160 // interface you get at the libbinder_ndk layer
161 auto ndkBinder = ndk::SpAIBinder(AIBinder_new(kNothingClass, nullptr));
162 auto binder = AIBinder_toPlatformBinder(ndkBinder.get());
163 doTransactFuzz<::android::Parcel>("binder_ndk", binder, std::move(provider));
164 },
165 [](FuzzedDataProvider&& provider) {
166 doReadFuzz<::android::hardware::Parcel>("hwbinder", HWBINDER_PARCEL_READ_FUNCTIONS,
167 std::move(provider));
168 },
169 [](FuzzedDataProvider&& provider) {
170 doReadFuzz<::android::Parcel>("binder", BINDER_PARCEL_READ_FUNCTIONS,
171 std::move(provider));
172 },
173 [](FuzzedDataProvider&& provider) {
174 doReadFuzz<NdkParcelAdapter>("binder_ndk", BINDER_NDK_PARCEL_READ_FUNCTIONS,
175 std::move(provider));
176 },
177 [](FuzzedDataProvider&& provider) {
178 doAppendFuzz<::android::Parcel>("binder", std::move(provider));
179 },
180 [](FuzzedDataProvider&& provider) {
181 doAppendFuzz<NdkParcelAdapter>("binder_ndk", std::move(provider));
182 },
183 };
184
185 provider.PickValueInArray(fuzzBackend)(std::move(provider));
186
187 return 0;
188 }
189