1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Runtime test cases for CONFIG_FORTIFY_SOURCE that aren't expected to 4 * Oops the kernel on success. (For those, see drivers/misc/lkdtm/fortify.c) 5 * 6 * For corner cases with UBSAN, try testing with: 7 * 8 * ./tools/testing/kunit/kunit.py run --arch=x86_64 \ 9 * --kconfig_add CONFIG_FORTIFY_SOURCE=y \ 10 * --kconfig_add CONFIG_UBSAN=y \ 11 * --kconfig_add CONFIG_UBSAN_TRAP=y \ 12 * --kconfig_add CONFIG_UBSAN_BOUNDS=y \ 13 * --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \ 14 * --make_options LLVM=1 fortify 15 */ 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <kunit/test.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/string.h> 22 #include <linux/vmalloc.h> 23 24 static const char array_of_10[] = "this is 10"; 25 static const char *ptr_of_11 = "this is 11!"; 26 static char array_unknown[] = "compiler thinks I might change"; 27 28 static void known_sizes_test(struct kunit *test) 29 { 30 KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); 31 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); 32 KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); 33 34 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); 35 /* Externally defined and dynamically sized string pointer: */ 36 KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); 37 } 38 39 /* This is volatile so the optimizer can't perform DCE below. */ 40 static volatile int pick; 41 42 /* Not inline to keep optimizer from figuring out which string we want. */ 43 static noinline size_t want_minus_one(int pick) 44 { 45 const char *str; 46 47 switch (pick) { 48 case 1: 49 str = "4444"; 50 break; 51 case 2: 52 str = "333"; 53 break; 54 default: 55 str = "1"; 56 break; 57 } 58 return __compiletime_strlen(str); 59 } 60 61 static void control_flow_split_test(struct kunit *test) 62 { 63 KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); 64 } 65 66 #define KUNIT_EXPECT_BOS(test, p, expected, name) \ 67 KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ 68 expected, \ 69 "__alloc_size() not working with __bos on " name "\n") 70 71 #if !__has_builtin(__builtin_dynamic_object_size) 72 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 73 /* Silence "unused variable 'expected'" warning. */ \ 74 KUNIT_EXPECT_EQ(test, expected, expected) 75 #else 76 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 77 KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ 78 expected, \ 79 "__alloc_size() not working with __bdos on " name "\n") 80 #endif 81 82 /* If the execpted size is a constant value, __bos can see it. */ 83 #define check_const(_expected, alloc, free) do { \ 84 size_t expected = (_expected); \ 85 void *p = alloc; \ 86 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 87 KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ 88 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 89 free; \ 90 } while (0) 91 92 /* If the execpted size is NOT a constant value, __bos CANNOT see it. */ 93 #define check_dynamic(_expected, alloc, free) do { \ 94 size_t expected = (_expected); \ 95 void *p = alloc; \ 96 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 97 KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ 98 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 99 free; \ 100 } while (0) 101 102 /* Assortment of constant-value kinda-edge cases. */ 103 #define CONST_TEST_BODY(TEST_alloc) do { \ 104 /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ 105 if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ 106 TEST_alloc(check_const, 0, 0); \ 107 TEST_alloc(check_const, 1, 1); \ 108 TEST_alloc(check_const, 128, 128); \ 109 TEST_alloc(check_const, 1023, 1023); \ 110 TEST_alloc(check_const, 1025, 1025); \ 111 TEST_alloc(check_const, 4096, 4096); \ 112 TEST_alloc(check_const, 4097, 4097); \ 113 } while (0) 114 115 static volatile size_t zero_size; 116 static volatile size_t unknown_size = 50; 117 118 #if !__has_builtin(__builtin_dynamic_object_size) 119 #define DYNAMIC_TEST_BODY(TEST_alloc) \ 120 kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") 121 #else 122 #define DYNAMIC_TEST_BODY(TEST_alloc) do { \ 123 size_t size = unknown_size; \ 124 \ 125 /* \ 126 * Expected size is "size" in each test, before it is then \ 127 * internally incremented in each test. Requires we disable \ 128 * -Wunsequenced. \ 129 */ \ 130 TEST_alloc(check_dynamic, size, size++); \ 131 /* Make sure incrementing actually happened. */ \ 132 KUNIT_EXPECT_NE(test, size, unknown_size); \ 133 } while (0) 134 #endif 135 136 #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ 137 static void alloc_size_##allocator##_const_test(struct kunit *test) \ 138 { \ 139 CONST_TEST_BODY(TEST_##allocator); \ 140 } \ 141 static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \ 142 { \ 143 DYNAMIC_TEST_BODY(TEST_##allocator); \ 144 } 145 146 #define TEST_kmalloc(checker, expected_size, alloc_size) do { \ 147 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 148 void *orig; \ 149 size_t len; \ 150 \ 151 checker(expected_size, kmalloc(alloc_size, gfp), \ 152 kfree(p)); \ 153 checker(expected_size, \ 154 kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 155 kfree(p)); \ 156 checker(expected_size, kzalloc(alloc_size, gfp), \ 157 kfree(p)); \ 158 checker(expected_size, \ 159 kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 160 kfree(p)); \ 161 checker(expected_size, kcalloc(1, alloc_size, gfp), \ 162 kfree(p)); \ 163 checker(expected_size, kcalloc(alloc_size, 1, gfp), \ 164 kfree(p)); \ 165 checker(expected_size, \ 166 kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 167 kfree(p)); \ 168 checker(expected_size, \ 169 kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 170 kfree(p)); \ 171 checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ 172 kfree(p)); \ 173 checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ 174 kfree(p)); \ 175 checker(expected_size, \ 176 kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 177 kfree(p)); \ 178 checker(expected_size, \ 179 kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 180 kfree(p)); \ 181 checker(expected_size, __kmalloc(alloc_size, gfp), \ 182 kfree(p)); \ 183 checker(expected_size, \ 184 __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 185 kfree(p)); \ 186 \ 187 orig = kmalloc(alloc_size, gfp); \ 188 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 189 checker((expected_size) * 2, \ 190 krealloc(orig, (alloc_size) * 2, gfp), \ 191 kfree(p)); \ 192 orig = kmalloc(alloc_size, gfp); \ 193 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 194 checker((expected_size) * 2, \ 195 krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ 196 kfree(p)); \ 197 orig = kmalloc(alloc_size, gfp); \ 198 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 199 checker((expected_size) * 2, \ 200 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ 201 kfree(p)); \ 202 \ 203 len = 11; \ 204 /* Using memdup() with fixed size, so force unknown length. */ \ 205 if (!__builtin_constant_p(expected_size)) \ 206 len += zero_size; \ 207 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ 208 } while (0) 209 DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) 210 211 /* Sizes are in pages, not bytes. */ 212 #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ 213 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 214 checker((expected_pages) * PAGE_SIZE, \ 215 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 216 checker((expected_pages) * PAGE_SIZE, \ 217 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 218 checker((expected_pages) * PAGE_SIZE, \ 219 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ 220 } while (0) 221 DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) 222 223 /* Sizes are in pages (and open-coded for side-effects), not bytes. */ 224 #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ 225 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 226 size_t prev_size; \ 227 void *orig; \ 228 \ 229 checker((expected_pages) * PAGE_SIZE, \ 230 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ 231 kvfree(p)); \ 232 checker((expected_pages) * PAGE_SIZE, \ 233 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 234 kvfree(p)); \ 235 checker((expected_pages) * PAGE_SIZE, \ 236 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ 237 kvfree(p)); \ 238 checker((expected_pages) * PAGE_SIZE, \ 239 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 240 kvfree(p)); \ 241 checker((expected_pages) * PAGE_SIZE, \ 242 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ 243 kvfree(p)); \ 244 checker((expected_pages) * PAGE_SIZE, \ 245 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ 246 kvfree(p)); \ 247 checker((expected_pages) * PAGE_SIZE, \ 248 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ 249 kvfree(p)); \ 250 checker((expected_pages) * PAGE_SIZE, \ 251 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ 252 kvfree(p)); \ 253 \ 254 prev_size = (expected_pages) * PAGE_SIZE; \ 255 orig = kvmalloc(prev_size, gfp); \ 256 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 257 checker(((expected_pages) * PAGE_SIZE) * 2, \ 258 kvrealloc(orig, prev_size, \ 259 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 260 kvfree(p)); \ 261 } while (0) 262 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 263 264 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 265 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 266 const char dev_name[] = "fortify-test"; \ 267 struct device *dev; \ 268 void *orig; \ 269 size_t len; \ 270 \ 271 /* Create dummy device for devm_kmalloc()-family tests. */ \ 272 dev = root_device_register(dev_name); \ 273 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 274 "Cannot register test device\n"); \ 275 \ 276 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 277 devm_kfree(dev, p)); \ 278 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 279 devm_kfree(dev, p)); \ 280 checker(expected_size, \ 281 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 282 devm_kfree(dev, p)); \ 283 checker(expected_size, \ 284 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 285 devm_kfree(dev, p)); \ 286 checker(expected_size, \ 287 devm_kcalloc(dev, 1, alloc_size, gfp), \ 288 devm_kfree(dev, p)); \ 289 checker(expected_size, \ 290 devm_kcalloc(dev, alloc_size, 1, gfp), \ 291 devm_kfree(dev, p)); \ 292 \ 293 orig = devm_kmalloc(dev, alloc_size, gfp); \ 294 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 295 checker((expected_size) * 2, \ 296 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 297 devm_kfree(dev, p)); \ 298 \ 299 len = 4; \ 300 /* Using memdup() with fixed size, so force unknown length. */ \ 301 if (!__builtin_constant_p(expected_size)) \ 302 len += zero_size; \ 303 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 304 devm_kfree(dev, p)); \ 305 \ 306 device_unregister(dev); \ 307 } while (0) 308 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 309 310 static struct kunit_case fortify_test_cases[] = { 311 KUNIT_CASE(known_sizes_test), 312 KUNIT_CASE(control_flow_split_test), 313 KUNIT_CASE(alloc_size_kmalloc_const_test), 314 KUNIT_CASE(alloc_size_kmalloc_dynamic_test), 315 KUNIT_CASE(alloc_size_vmalloc_const_test), 316 KUNIT_CASE(alloc_size_vmalloc_dynamic_test), 317 KUNIT_CASE(alloc_size_kvmalloc_const_test), 318 KUNIT_CASE(alloc_size_kvmalloc_dynamic_test), 319 KUNIT_CASE(alloc_size_devm_kmalloc_const_test), 320 KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test), 321 {} 322 }; 323 324 static struct kunit_suite fortify_test_suite = { 325 .name = "fortify", 326 .test_cases = fortify_test_cases, 327 }; 328 329 kunit_test_suite(fortify_test_suite); 330 331 MODULE_LICENSE("GPL"); 332