lib/test_ubsan.c

   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");