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 #define UBSAN_TEST(config, ...) do { \ 9 pr_info("%s " __VA_ARGS__ "%s(%s=%s)\n", __func__, \ 10 sizeof(" " __VA_ARGS__) > 2 ? " " : "", \ 11 #config, IS_ENABLED(config) ? "y" : "n"); \ 12 } while (0) 13 14 static void test_ubsan_add_overflow(void) 15 { 16 volatile int val = INT_MAX; 17 volatile unsigned int uval = UINT_MAX; 18 19 UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW); 20 val += 2; 21 22 UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW); 23 uval += 2; 24 } 25 26 static void test_ubsan_sub_overflow(void) 27 { 28 volatile int val = INT_MIN; 29 volatile unsigned int uval = 0; 30 volatile int val2 = 2; 31 32 UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW); 33 val -= val2; 34 35 UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW); 36 uval -= val2; 37 } 38 39 static void test_ubsan_mul_overflow(void) 40 { 41 volatile int val = INT_MAX / 2; 42 volatile unsigned int uval = UINT_MAX / 2; 43 44 UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW); 45 val *= 3; 46 47 UBSAN_TEST(CONFIG_UBSAN_UNSIGNED_OVERFLOW); 48 uval *= 3; 49 } 50 51 static void test_ubsan_negate_overflow(void) 52 { 53 volatile int val = INT_MIN; 54 55 UBSAN_TEST(CONFIG_UBSAN_SIGNED_OVERFLOW); 56 val = -val; 57 } 58 59 static void test_ubsan_divrem_overflow(void) 60 { 61 volatile int val = 16; 62 volatile int val2 = 0; 63 64 UBSAN_TEST(CONFIG_UBSAN_DIV_ZERO); 65 val /= val2; 66 } 67 68 static void test_ubsan_shift_out_of_bounds(void) 69 { 70 volatile int neg = -1, wrap = 4; 71 int val1 = 10; 72 int val2 = INT_MAX; 73 74 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "negative exponent"); 75 val1 <<= neg; 76 77 UBSAN_TEST(CONFIG_UBSAN_SHIFT, "left overflow"); 78 val2 <<= wrap; 79 } 80 81 static void test_ubsan_out_of_bounds(void) 82 { 83 volatile int i = 4, j = 5, k = -1; 84 volatile char above[4] = { }; /* Protect surrounding memory. */ 85 volatile int arr[4]; 86 volatile char below[4] = { }; /* Protect surrounding memory. */ 87 88 above[0] = below[0]; 89 90 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "above"); 91 arr[j] = i; 92 93 UBSAN_TEST(CONFIG_UBSAN_BOUNDS, "below"); 94 arr[k] = i; 95 } 96 97 enum ubsan_test_enum { 98 UBSAN_TEST_ZERO = 0, 99 UBSAN_TEST_ONE, 100 UBSAN_TEST_MAX, 101 }; 102 103 static void test_ubsan_load_invalid_value(void) 104 { 105 volatile char *dst, *src; 106 bool val, val2, *ptr; 107 enum ubsan_test_enum eval, eval2, *eptr; 108 unsigned char c = 0xff; 109 110 UBSAN_TEST(CONFIG_UBSAN_BOOL, "bool"); 111 dst = (char *)&val; 112 src = &c; 113 *dst = *src; 114 115 ptr = &val2; 116 val2 = val; 117 118 UBSAN_TEST(CONFIG_UBSAN_ENUM, "enum"); 119 dst = (char *)&eval; 120 src = &c; 121 *dst = *src; 122 123 eptr = &eval2; 124 eval2 = eval; 125 } 126 127 static void test_ubsan_null_ptr_deref(void) 128 { 129 volatile int *ptr = NULL; 130 int val; 131 132 UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE); 133 val = *ptr; 134 } 135 136 static void test_ubsan_misaligned_access(void) 137 { 138 volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5}; 139 volatile int *ptr, val = 6; 140 141 UBSAN_TEST(CONFIG_UBSAN_ALIGNMENT); 142 ptr = (int *)(arr + 1); 143 *ptr = val; 144 } 145 146 static void test_ubsan_object_size_mismatch(void) 147 { 148 /* "((aligned(8)))" helps this not into be misaligned for ptr-access. */ 149 volatile int val __aligned(8) = 4; 150 volatile long long *ptr, val2; 151 152 UBSAN_TEST(CONFIG_UBSAN_OBJECT_SIZE); 153 ptr = (long long *)&val; 154 val2 = *ptr; 155 } 156 157 static const test_ubsan_fp test_ubsan_array[] = { 158 test_ubsan_add_overflow, 159 test_ubsan_sub_overflow, 160 test_ubsan_mul_overflow, 161 test_ubsan_negate_overflow, 162 test_ubsan_shift_out_of_bounds, 163 test_ubsan_out_of_bounds, 164 test_ubsan_load_invalid_value, 165 test_ubsan_misaligned_access, 166 test_ubsan_object_size_mismatch, 167 }; 168 169 /* Excluded because they Oops the module. */ 170 static const test_ubsan_fp skip_ubsan_array[] = { 171 test_ubsan_divrem_overflow, 172 test_ubsan_null_ptr_deref, 173 }; 174 175 static int __init test_ubsan_init(void) 176 { 177 unsigned int i; 178 179 for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++) 180 test_ubsan_array[i](); 181 182 return 0; 183 } 184 module_init(test_ubsan_init); 185 186 static void __exit test_ubsan_exit(void) 187 { 188 /* do nothing */ 189 } 190 module_exit(test_ubsan_exit); 191 192 MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>"); 193 MODULE_LICENSE("GPL v2"); 194