1 /**
2 * Copyright (C) 2020 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
17 #include "../includes/common.h"
18 #include <dlfcn.h>
19 #include <fcntl.h>
20 #include <ipp.h>
21
22 int isInitialized = 0;
23 void *check_ptr = NULL;
24 size_t text_len = sizeof("text/plain") - 1;
25
26 static void *(*real_malloc)(size_t) = NULL;
27 static int (*real_strcmp)(const char *str1, const char *str2) = NULL;
28
init(void)29 void init(void) {
30 real_malloc = (void *(*)(size_t))dlsym(RTLD_NEXT, "malloc");
31 if (real_malloc == NULL) {
32 return;
33 }
34 real_strcmp = (int (*)(const char *, const char *))dlsym(RTLD_NEXT, "strcmp");
35 if (real_strcmp == NULL) {
36 return;
37 }
38 isInitialized = 1;
39 }
40
malloc(size_t size)41 void *malloc(size_t size) {
42 if (!isInitialized) {
43 init();
44 }
45 void *tmp = real_malloc(size);
46 if (size == text_len) {
47 check_ptr = tmp;
48 }
49 return tmp;
50 }
51
strcmp(const char * str1,const char * str2)52 int strcmp(const char *str1, const char *str2) {
53 if (!isInitialized) {
54 init();
55 }
56 if ((str1 == check_ptr) && (str1[text_len - 1] != '\0')) {
57 exit(EXIT_VULNERABLE);
58 }
59 return real_strcmp(str1, str2);
60 }
61
main(int argc,char ** argv)62 int main(int argc, char **argv) {
63 if (argc < 2) {
64 return EXIT_FAILURE;
65 }
66
67 int file_desc = open((const char *)argv[1], O_RDONLY);
68 if (file_desc < 0) {
69 return EXIT_FAILURE;
70 }
71
72 ipp_t *job = ippNew();
73 if (!job) {
74 return EXIT_FAILURE;
75 }
76 ippReadFile(file_desc, job);
77
78 if (job) {
79 free(job);
80 }
81 close(file_desc);
82 return EXIT_SUCCESS;
83 }
84