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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 <stdlib.h>
17 #include <unistd.h>
18 #include <sys/wait.h>
19 #include <signal.h>
20 #include <errno.h>
21 #include <string.h>
22 #include "test.h"
23 
handler(int s)24 static void handler(int s)
25 {
26 }
27 
28 volatile uintptr_t *p0;
29 volatile uintptr_t *p1;
30 volatile void *tmp[512];
31 
child(void)32 static int child(void)
33 {
34 	p0 = (uintptr_t *)malloc(10 * sizeof(uintptr_t));
35 	if (!p0) {
36 		t_error("Malloc failed:%s\n", strerror(errno));
37 		return -1;
38 	}
39 	/* Malloc a dividing chunk to avoid combination of neighbouring freed chunk */
40 	tmp[0] = malloc(10 * sizeof(uintptr_t));
41 	/* Malloc another chunk to get a key */
42 	p1 = (uintptr_t *)malloc(10 * sizeof(uintptr_t));
43 	if (!p1) {
44 		t_error("Malloc failed:%s\n", strerror(errno));
45 		return -1;
46 	}
47 	/* Malloc a dividing chunk to avoid combination of neighbouring freed chunk */
48 	tmp[0] = malloc(10 * sizeof(uintptr_t));
49 
50 	free((void *)p0);
51 	free((void *)p1);
52 
53 	uintptr_t *fake_ptr = (uintptr_t *)((uintptr_t)((char *)p1 - sizeof(size_t) * 2) ^ (uintptr_t)p0[0]);
54 	p0[0] = (uintptr_t)fake_ptr;
55 	p1[0] = (uintptr_t)fake_ptr;
56 
57 	/*
58 	 * The init procedure makes the freelist unpredictable. To make sure to trigger the ivalid ptr
59 	 * acess, here we create as many chunks as possible to make sure there are enough chunks in
60 	 * bin[j] of size "10 * sizeof(uintptr_t)". Basically this is heap spray.
61 	 */
62 	for (int i = 0; i < 512; ++i) {
63 		tmp[i] = malloc(10 *sizeof(uintptr_t));
64 	}
65 
66 	/*
67 	 * When freelist quarantine is on, the modifiy-pointer chunk maybe in quarantine. So here we
68 	 * need free the pointer.
69 	 */
70 	for (int i = 0; i < 512; ++i) {
71 		free((void *)tmp[i]);
72 	}
73 	return 0;
74 }
75 
start_child(void)76 static pid_t start_child(void)
77 {
78 	pid_t pid;
79 	int ret;
80 	pid = fork();
81 	if (pid == 0) {
82 		ret = child();
83 		t_error("child process normally out with %d\n", ret);
84 		return ret;
85 	}
86 	return pid;
87 }
88 
main(int argc,char * argv[])89 int main(int argc, char *argv[])
90 {
91 	sigset_t set;
92 	int status;
93 	pid_t pid;
94 	int flag = 0;
95 
96 	sigemptyset(&set);
97 	sigaddset(&set, SIGCHLD);
98 	sigprocmask(SIG_BLOCK, &set, 0);
99 	signal(SIGCHLD, handler);
100 
101 	pid = start_child();
102 	if (pid == -1) {
103 		t_error("%s fork failed: %s\n", argv[0], strerror(errno));
104 		return -1;
105 	}
106 	if (sigtimedwait(&set, 0, &(struct timespec){5, 0}) == -1) { /* Wait for 5 seconds */
107 		if (errno == EAGAIN)
108 			flag = 1;
109 		else
110 			t_error("%s sigtimedwait failed: %s\n", argv[0], strerror(errno));
111 		if (kill(pid, SIGKILL) == -1)
112 			t_error("%s kill failed: %s\n", argv[0], strerror(errno));
113 	}
114 
115 	if (waitpid(pid, &status, 0) != pid) {
116 		t_error("%s waitpid failed: %s\n", argv[0], strerror(errno));
117 		return -1;
118 	}
119 
120 	if (flag) {
121 		t_error("Child process time out\n");
122 	}
123 
124 	if (WIFSIGNALED(status)) {
125 		if (WTERMSIG(status) != SIGSEGV && WTERMSIG(status) != SIGILL) {
126 			t_error("%s child process out with %s\n", argv[0], strsignal(WTERMSIG(status)));
127 			return -1;
128 		}
129 	} else {
130 		t_error("%s child process finished normally\n", argv[0]);
131 	}
132 	return 0;
133 }
134