1 // Copyright 2020 Google LLC
2 //
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 #include <stddef.h>
16 #include <stdint.h>
17 #include <unistd.h>
18 #include <assert.h>
19 #include <sys/syscall.h>
20 #include <linux/memfd.h>
21 #include <fuzzer/FuzzedDataProvider.h>
22
23 #include "ext2fs/ext2fs.h"
24
LLVMFuzzerTestOneInput(const uint8_t * data,size_t size)25 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
26
27 enum FuzzerType {
28 ext2fsImageBitmapRead,
29 ext2fsImageInodeRead,
30 ext2fsImageSuperRead,
31 ext2fsImageBitmapWrite,
32 ext2fsImageInodeWrite,
33 ext2fsImageSuperWrite,
34 kMaxValue = ext2fsImageSuperWrite
35 };
36
37 FuzzedDataProvider stream(data, size);
38 const FuzzerType f = stream.ConsumeEnum<FuzzerType>();
39 static const char* fname = "/tmp/ext2_test_file";
40
41 // Write our data to a temp file.
42 int fd = syscall(SYS_memfd_create, fname, 0);
43 std::vector<char> buffer = stream.ConsumeRemainingBytes<char>();
44 write(fd, buffer.data(), buffer.size());
45 close(fd);
46
47 ext2_filsys fs;
48 errcode_t retval = ext2fs_open(
49 fname,
50 0, 0, 0,
51 unix_io_manager,
52 &fs);
53
54 if (!retval) {
55 switch (f) {
56 case ext2fsImageBitmapRead: {
57 ext2fs_image_bitmap_read(fs, fd, 0);
58 break;
59 }
60 case ext2fsImageInodeRead: {
61 ext2fs_image_inode_read(fs, fd, 0);
62 break;
63 }
64 case ext2fsImageSuperRead: {
65 ext2fs_image_super_read(fs, fd, 0);
66 break;
67 }
68 case ext2fsImageBitmapWrite: {
69 ext2fs_image_bitmap_write(fs, fd, 0);
70 break;
71 }
72 case ext2fsImageInodeWrite: {
73 ext2fs_image_inode_write(fs, fd, 0);
74 break;
75 }
76 case ext2fsImageSuperWrite: {
77 ext2fs_image_super_write(fs, fd, 0);
78 break;
79 }
80 default: {
81 assert(false);
82 }
83 }
84 ext2fs_close(fs);
85 }
86
87 return 0;
88 }
89