xref: /linux/lib/test_ubsan.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/init.h>
3 #include <linux/kernel.h>
4 #include <linux/module.h>
5 
6 typedef void(*test_ubsan_fp)(void);
7 
8 static void test_ubsan_add_overflow(void)
9 {
10 	volatile int val = INT_MAX;
11 
12 	val += 2;
13 }
14 
15 static void test_ubsan_sub_overflow(void)
16 {
17 	volatile int val = INT_MIN;
18 	volatile int val2 = 2;
19 
20 	val -= val2;
21 }
22 
23 static void test_ubsan_mul_overflow(void)
24 {
25 	volatile int val = INT_MAX / 2;
26 
27 	val *= 3;
28 }
29 
30 static void test_ubsan_negate_overflow(void)
31 {
32 	volatile int val = INT_MIN;
33 
34 	val = -val;
35 }
36 
37 static void test_ubsan_divrem_overflow(void)
38 {
39 	volatile int val = 16;
40 	volatile int val2 = 0;
41 
42 	val /= val2;
43 }
44 
45 static void test_ubsan_vla_bound_not_positive(void)
46 {
47 	volatile int size = -1;
48 	char buf[size];
49 
50 	(void)buf;
51 }
52 
53 static void test_ubsan_shift_out_of_bounds(void)
54 {
55 	volatile int val = -1;
56 	int val2 = 10;
57 
58 	val2 <<= val;
59 }
60 
61 static void test_ubsan_out_of_bounds(void)
62 {
63 	volatile int i = 4, j = 5;
64 	volatile int arr[i];
65 
66 	arr[j] = i;
67 }
68 
69 static void test_ubsan_load_invalid_value(void)
70 {
71 	volatile char *dst, *src;
72 	bool val, val2, *ptr;
73 	char c = 4;
74 
75 	dst = (char *)&val;
76 	src = &c;
77 	*dst = *src;
78 
79 	ptr = &val2;
80 	val2 = val;
81 }
82 
83 static void test_ubsan_null_ptr_deref(void)
84 {
85 	volatile int *ptr = NULL;
86 	int val;
87 
88 	val = *ptr;
89 }
90 
91 static void test_ubsan_misaligned_access(void)
92 {
93 	volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
94 	volatile int *ptr, val = 6;
95 
96 	ptr = (int *)(arr + 1);
97 	*ptr = val;
98 }
99 
100 static void test_ubsan_object_size_mismatch(void)
101 {
102 	/* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
103 	volatile int val __aligned(8) = 4;
104 	volatile long long *ptr, val2;
105 
106 	ptr = (long long *)&val;
107 	val2 = *ptr;
108 }
109 
110 static const test_ubsan_fp test_ubsan_array[] = {
111 	test_ubsan_add_overflow,
112 	test_ubsan_sub_overflow,
113 	test_ubsan_mul_overflow,
114 	test_ubsan_negate_overflow,
115 	test_ubsan_divrem_overflow,
116 	test_ubsan_vla_bound_not_positive,
117 	test_ubsan_shift_out_of_bounds,
118 	test_ubsan_out_of_bounds,
119 	test_ubsan_load_invalid_value,
120 	//test_ubsan_null_ptr_deref, /* exclude it because there is a crash */
121 	test_ubsan_misaligned_access,
122 	test_ubsan_object_size_mismatch,
123 };
124 
125 static int __init test_ubsan_init(void)
126 {
127 	unsigned int i;
128 
129 	for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
130 		test_ubsan_array[i]();
131 
132 	(void)test_ubsan_null_ptr_deref; /* to avoid unsed-function warning */
133 	return 0;
134 }
135 module_init(test_ubsan_init);
136 
137 static void __exit test_ubsan_exit(void)
138 {
139 	/* do nothing */
140 }
141 module_exit(test_ubsan_exit);
142 
143 MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
144 MODULE_LICENSE("GPL v2");
145