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_shift_out_of_bounds(void)
  46 {
  47         volatile int val = -1;
  48         int val2 = 10;
  49
  50         val2 <<= val;
  51 }
  52
  53 static void test_ubsan_out_of_bounds(void)
  54 {
  55         volatile int i = 4, j = 5;
  56         volatile int arr[4];
  57
  58         arr[j] = i;
  59 }
  60
  61 static void test_ubsan_load_invalid_value(void)
  62 {
  63         volatile char *dst, *src;
  64         bool val, val2, *ptr;
  65         char c = 4;
  66
  67         dst = (char *)&val;
  68         src = &c;
  69         *dst = *src;
  70
  71         ptr = &val2;
  72         val2 = val;
  73 }
  74
  75 static void test_ubsan_null_ptr_deref(void)
  76 {
  77         volatile int *ptr = NULL;
  78         int val;
  79
  80         val = *ptr;
  81 }
  82
  83 static void test_ubsan_misaligned_access(void)
  84 {
  85         volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5};
  86         volatile int *ptr, val = 6;
  87
  88         ptr = (int *)(arr + 1);
  89         *ptr = val;
  90 }
  91
  92 static void test_ubsan_object_size_mismatch(void)
  93 {
  94         /* "((aligned(8)))" helps this not into be misaligned for ptr-access. */
  95         volatile int val __aligned(8) = 4;
  96         volatile long long *ptr, val2;
  97
  98         ptr = (long long *)&val;
  99         val2 = *ptr;
 100 }
 101
 102 static const test_ubsan_fp test_ubsan_array[] = {
 103         test_ubsan_add_overflow,
 104         test_ubsan_sub_overflow,
 105         test_ubsan_mul_overflow,
 106         test_ubsan_negate_overflow,
 107         test_ubsan_divrem_overflow,
 108         test_ubsan_shift_out_of_bounds,
 109         test_ubsan_out_of_bounds,
 110         test_ubsan_load_invalid_value,
 111         //test_ubsan_null_ptr_deref, /* exclude it because there is a crash */
 112         test_ubsan_misaligned_access,
 113         test_ubsan_object_size_mismatch,
 114 };
 115
 116 static int __init test_ubsan_init(void)
 117 {
 118         unsigned int i;
 119
 120         for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++)
 121                 test_ubsan_array[i]();
 122
 123         (void)test_ubsan_null_ptr_deref; /* to avoid unsed-function warning */
 124         return 0;
 125 }
 126 module_init(test_ubsan_init);
 127
 128 static void __exit test_ubsan_exit(void)
 129 {
 130         /* do nothing */
 131 }
 132 module_exit(test_ubsan_exit);
 133
 134 MODULE_AUTHOR("Jinbum Park <jinb.park7@gmail.com>");
 135 MODULE_LICENSE("GPL v2");