1 /*
2  * Copyright (c) 2022 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "formashmem_fuzzer.h"
17 
18 #include <cstddef>
19 #include <cstdint>
20 
21 #define private public
22 #define protected public
23 #include "form_ashmem.h"
24 #undef private
25 #undef protected
26 #include "securec.h"
27 
28 using namespace OHOS::AppExecFwk;
29 
30 namespace OHOS {
31 constexpr size_t FOO_MAX_LEN = 1024;
32 constexpr size_t U32_AT_SIZE = 4;
GetU32Data(const char * ptr)33 uint32_t GetU32Data(const char* ptr)
34 {
35     // convert fuzz input data to an integer
36     return (ptr[0] << 24) | (ptr[1] << 16) | (ptr[2] << 8) | ptr[3];
37 }
DoSomethingInterestingWithMyAPI(const char * data,size_t size)38 bool DoSomethingInterestingWithMyAPI(const char* data, size_t size)
39 {
40     FormAshmem formAshmem;
41     std::string name(data);
42     int32_t sizes = static_cast<int32_t>(GetU32Data(data));
43     formAshmem.WriteToAshmem(name, nullptr, sizes);
44     formAshmem.GetAshmemSize();
45     return formAshmem.GetAshmemFd();
46 }
47 }
48 
49 /* Fuzzer entry point */
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)50 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
51 {
52     /* Run your code on data */
53     if (data == nullptr) {
54         return 0;
55     }
56 
57     if (size < OHOS::U32_AT_SIZE) {
58         return 0;
59     }
60 
61     /* Validate the length of size */
62     if (size == 0 || size > OHOS::FOO_MAX_LEN) {
63         return 0;
64     }
65 
66     char* ch = static_cast<char*>(malloc(size + 1));
67     if (ch == nullptr) {
68         return 0;
69     }
70 
71     (void)memset_s(ch, size + 1, 0x00, size + 1);
72     if (memcpy_s(ch, size + 1, data, size) != EOK) {
73         free(ch);
74         ch = nullptr;
75         return 0;
76     }
77 
78     OHOS::DoSomethingInterestingWithMyAPI(ch, size);
79     free(ch);
80     ch = nullptr;
81     return 0;
82 }
83 
84