1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Runtime test cases for CONFIG_FORTIFY_SOURCE. For additional memcpy() 4 * testing see FORTIFY_MEM_* tests in LKDTM (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 /* We don't need to fill dmesg with the fortify WARNs during testing. */ 19 #ifdef DEBUG 20 # define FORTIFY_REPORT_KUNIT(x...) __fortify_report(x) 21 # define FORTIFY_WARN_KUNIT(x...) WARN_ONCE(x) 22 #else 23 # define FORTIFY_REPORT_KUNIT(x...) do { } while (0) 24 # define FORTIFY_WARN_KUNIT(x...) do { } while (0) 25 #endif 26 27 /* Redefine fortify_panic() to track failures. */ 28 void fortify_add_kunit_error(int write); 29 #define fortify_panic(func, write, avail, size, retfail) do { \ 30 FORTIFY_REPORT_KUNIT(FORTIFY_REASON(func, write), avail, size); \ 31 fortify_add_kunit_error(write); \ 32 return (retfail); \ 33 } while (0) 34 35 /* Redefine fortify_warn_once() to track memcpy() failures. */ 36 #define fortify_warn_once(chk_func, x...) do { \ 37 bool __result = chk_func; \ 38 FORTIFY_WARN_KUNIT(__result, x); \ 39 if (__result) \ 40 fortify_add_kunit_error(1); \ 41 } while (0) 42 43 #include <kunit/device.h> 44 #include <kunit/test.h> 45 #include <kunit/test-bug.h> 46 #include <linux/device.h> 47 #include <linux/slab.h> 48 #include <linux/string.h> 49 #include <linux/vmalloc.h> 50 51 /* Handle being built without CONFIG_FORTIFY_SOURCE */ 52 #ifndef __compiletime_strlen 53 # define __compiletime_strlen __builtin_strlen 54 #endif 55 56 static struct kunit_resource read_resource; 57 static struct kunit_resource write_resource; 58 static int fortify_read_overflows; 59 static int fortify_write_overflows; 60 61 static const char array_of_10[] = "this is 10"; 62 static const char *ptr_of_11 = "this is 11!"; 63 static char array_unknown[] = "compiler thinks I might change"; 64 65 void fortify_add_kunit_error(int write) 66 { 67 struct kunit_resource *resource; 68 struct kunit *current_test; 69 70 current_test = kunit_get_current_test(); 71 if (!current_test) 72 return; 73 74 resource = kunit_find_named_resource(current_test, 75 write ? "fortify_write_overflows" 76 : "fortify_read_overflows"); 77 if (!resource) 78 return; 79 80 (*(int *)resource->data)++; 81 kunit_put_resource(resource); 82 } 83 84 static void fortify_test_known_sizes(struct kunit *test) 85 { 86 KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); 87 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); 88 KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); 89 90 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); 91 /* Externally defined and dynamically sized string pointer: */ 92 KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); 93 } 94 95 /* This is volatile so the optimizer can't perform DCE below. */ 96 static volatile int pick; 97 98 /* Not inline to keep optimizer from figuring out which string we want. */ 99 static noinline size_t want_minus_one(int pick) 100 { 101 const char *str; 102 103 switch (pick) { 104 case 1: 105 str = "4444"; 106 break; 107 case 2: 108 str = "333"; 109 break; 110 default: 111 str = "1"; 112 break; 113 } 114 return __compiletime_strlen(str); 115 } 116 117 static void fortify_test_control_flow_split(struct kunit *test) 118 { 119 KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); 120 } 121 122 #define KUNIT_EXPECT_BOS(test, p, expected, name) \ 123 KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ 124 expected, \ 125 "__alloc_size() not working with __bos on " name "\n") 126 127 #if !__has_builtin(__builtin_dynamic_object_size) 128 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 129 /* Silence "unused variable 'expected'" warning. */ \ 130 KUNIT_EXPECT_EQ(test, expected, expected) 131 #else 132 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 133 KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ 134 expected, \ 135 "__alloc_size() not working with __bdos on " name "\n") 136 #endif 137 138 /* If the execpted size is a constant value, __bos can see it. */ 139 #define check_const(_expected, alloc, free) do { \ 140 size_t expected = (_expected); \ 141 void *p = alloc; \ 142 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 143 KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ 144 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 145 free; \ 146 } while (0) 147 148 /* If the execpted size is NOT a constant value, __bos CANNOT see it. */ 149 #define check_dynamic(_expected, alloc, free) do { \ 150 size_t expected = (_expected); \ 151 void *p = alloc; \ 152 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 153 KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ 154 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 155 free; \ 156 } while (0) 157 158 /* Assortment of constant-value kinda-edge cases. */ 159 #define CONST_TEST_BODY(TEST_alloc) do { \ 160 /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ 161 if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ 162 TEST_alloc(check_const, 0, 0); \ 163 TEST_alloc(check_const, 1, 1); \ 164 TEST_alloc(check_const, 128, 128); \ 165 TEST_alloc(check_const, 1023, 1023); \ 166 TEST_alloc(check_const, 1025, 1025); \ 167 TEST_alloc(check_const, 4096, 4096); \ 168 TEST_alloc(check_const, 4097, 4097); \ 169 } while (0) 170 171 static volatile size_t zero_size; 172 static volatile size_t unknown_size = 50; 173 174 #if !__has_builtin(__builtin_dynamic_object_size) 175 #define DYNAMIC_TEST_BODY(TEST_alloc) \ 176 kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") 177 #else 178 #define DYNAMIC_TEST_BODY(TEST_alloc) do { \ 179 size_t size = unknown_size; \ 180 \ 181 /* \ 182 * Expected size is "size" in each test, before it is then \ 183 * internally incremented in each test. Requires we disable \ 184 * -Wunsequenced. \ 185 */ \ 186 TEST_alloc(check_dynamic, size, size++); \ 187 /* Make sure incrementing actually happened. */ \ 188 KUNIT_EXPECT_NE(test, size, unknown_size); \ 189 } while (0) 190 #endif 191 192 #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ 193 static void fortify_test_alloc_size_##allocator##_const(struct kunit *test) \ 194 { \ 195 CONST_TEST_BODY(TEST_##allocator); \ 196 } \ 197 static void fortify_test_alloc_size_##allocator##_dynamic(struct kunit *test) \ 198 { \ 199 DYNAMIC_TEST_BODY(TEST_##allocator); \ 200 } 201 202 #define TEST_kmalloc(checker, expected_size, alloc_size) do { \ 203 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 204 void *orig; \ 205 size_t len; \ 206 \ 207 checker(expected_size, kmalloc(alloc_size, gfp), \ 208 kfree(p)); \ 209 checker(expected_size, \ 210 kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 211 kfree(p)); \ 212 checker(expected_size, kzalloc(alloc_size, gfp), \ 213 kfree(p)); \ 214 checker(expected_size, \ 215 kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 216 kfree(p)); \ 217 checker(expected_size, kcalloc(1, alloc_size, gfp), \ 218 kfree(p)); \ 219 checker(expected_size, kcalloc(alloc_size, 1, gfp), \ 220 kfree(p)); \ 221 checker(expected_size, \ 222 kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 223 kfree(p)); \ 224 checker(expected_size, \ 225 kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 226 kfree(p)); \ 227 checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ 228 kfree(p)); \ 229 checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ 230 kfree(p)); \ 231 checker(expected_size, \ 232 kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 233 kfree(p)); \ 234 checker(expected_size, \ 235 kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 236 kfree(p)); \ 237 \ 238 orig = kmalloc(alloc_size, gfp); \ 239 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 240 checker((expected_size) * 2, \ 241 krealloc(orig, (alloc_size) * 2, gfp), \ 242 kfree(p)); \ 243 orig = kmalloc(alloc_size, gfp); \ 244 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 245 checker((expected_size) * 2, \ 246 krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ 247 kfree(p)); \ 248 orig = kmalloc(alloc_size, gfp); \ 249 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 250 checker((expected_size) * 2, \ 251 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ 252 kfree(p)); \ 253 \ 254 len = 11; \ 255 /* Using memdup() with fixed size, so force unknown length. */ \ 256 if (!__builtin_constant_p(expected_size)) \ 257 len += zero_size; \ 258 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ 259 } while (0) 260 DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) 261 262 /* Sizes are in pages, not bytes. */ 263 #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ 264 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 265 checker((expected_pages) * PAGE_SIZE, \ 266 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 267 checker((expected_pages) * PAGE_SIZE, \ 268 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 269 checker((expected_pages) * PAGE_SIZE, \ 270 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ 271 } while (0) 272 DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) 273 274 /* Sizes are in pages (and open-coded for side-effects), not bytes. */ 275 #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ 276 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 277 size_t prev_size; \ 278 void *orig; \ 279 \ 280 checker((expected_pages) * PAGE_SIZE, \ 281 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ 282 kvfree(p)); \ 283 checker((expected_pages) * PAGE_SIZE, \ 284 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 285 kvfree(p)); \ 286 checker((expected_pages) * PAGE_SIZE, \ 287 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ 288 kvfree(p)); \ 289 checker((expected_pages) * PAGE_SIZE, \ 290 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 291 kvfree(p)); \ 292 checker((expected_pages) * PAGE_SIZE, \ 293 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ 294 kvfree(p)); \ 295 checker((expected_pages) * PAGE_SIZE, \ 296 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ 297 kvfree(p)); \ 298 checker((expected_pages) * PAGE_SIZE, \ 299 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ 300 kvfree(p)); \ 301 checker((expected_pages) * PAGE_SIZE, \ 302 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ 303 kvfree(p)); \ 304 \ 305 prev_size = (expected_pages) * PAGE_SIZE; \ 306 orig = kvmalloc(prev_size, gfp); \ 307 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 308 checker(((expected_pages) * PAGE_SIZE) * 2, \ 309 kvrealloc(orig, ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 310 kvfree(p)); \ 311 } while (0) 312 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 313 314 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 315 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 316 const char dev_name[] = "fortify-test"; \ 317 struct device *dev; \ 318 void *orig; \ 319 size_t len; \ 320 \ 321 /* Create dummy device for devm_kmalloc()-family tests. */ \ 322 dev = kunit_device_register(test, dev_name); \ 323 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 324 "Cannot register test device\n"); \ 325 \ 326 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 327 devm_kfree(dev, p)); \ 328 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 329 devm_kfree(dev, p)); \ 330 checker(expected_size, \ 331 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 332 devm_kfree(dev, p)); \ 333 checker(expected_size, \ 334 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 335 devm_kfree(dev, p)); \ 336 checker(expected_size, \ 337 devm_kcalloc(dev, 1, alloc_size, gfp), \ 338 devm_kfree(dev, p)); \ 339 checker(expected_size, \ 340 devm_kcalloc(dev, alloc_size, 1, gfp), \ 341 devm_kfree(dev, p)); \ 342 \ 343 orig = devm_kmalloc(dev, alloc_size, gfp); \ 344 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 345 checker((expected_size) * 2, \ 346 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 347 devm_kfree(dev, p)); \ 348 \ 349 len = 4; \ 350 /* Using memdup() with fixed size, so force unknown length. */ \ 351 if (!__builtin_constant_p(expected_size)) \ 352 len += zero_size; \ 353 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 354 devm_kfree(dev, p)); \ 355 \ 356 kunit_device_unregister(test, dev); \ 357 } while (0) 358 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 359 360 static const char * const test_strs[] = { 361 "", 362 "Hello there", 363 "A longer string, just for variety", 364 }; 365 366 #define TEST_realloc(checker) do { \ 367 gfp_t gfp = GFP_KERNEL; \ 368 size_t len; \ 369 int i; \ 370 \ 371 for (i = 0; i < ARRAY_SIZE(test_strs); i++) { \ 372 len = strlen(test_strs[i]); \ 373 KUNIT_EXPECT_EQ(test, __builtin_constant_p(len), 0); \ 374 checker(len, kmemdup_array(test_strs[i], 1, len, gfp), \ 375 kfree(p)); \ 376 checker(len, kmemdup(test_strs[i], len, gfp), \ 377 kfree(p)); \ 378 } \ 379 } while (0) 380 static void fortify_test_realloc_size(struct kunit *test) 381 { 382 TEST_realloc(check_dynamic); 383 } 384 385 /* 386 * We can't have an array at the end of a structure or else 387 * builds without -fstrict-flex-arrays=3 will report them as 388 * being an unknown length. Additionally, add bytes before 389 * and after the string to catch over/underflows if tests 390 * fail. 391 */ 392 struct fortify_padding { 393 unsigned long bytes_before; 394 char buf[32]; 395 unsigned long bytes_after; 396 }; 397 /* Force compiler into not being able to resolve size at compile-time. */ 398 static volatile int unconst; 399 400 static void fortify_test_strlen(struct kunit *test) 401 { 402 struct fortify_padding pad = { }; 403 int i, end = sizeof(pad.buf) - 1; 404 405 /* Fill 31 bytes with valid characters. */ 406 for (i = 0; i < sizeof(pad.buf) - 1; i++) 407 pad.buf[i] = i + '0'; 408 /* Trailing bytes are still %NUL. */ 409 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 410 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 411 412 /* String is terminated, so strlen() is valid. */ 413 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 414 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 415 416 /* Make string unterminated, and recount. */ 417 pad.buf[end] = 'A'; 418 end = sizeof(pad.buf); 419 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 420 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 421 } 422 423 static void fortify_test_strnlen(struct kunit *test) 424 { 425 struct fortify_padding pad = { }; 426 int i, end = sizeof(pad.buf) - 1; 427 428 /* Fill 31 bytes with valid characters. */ 429 for (i = 0; i < sizeof(pad.buf) - 1; i++) 430 pad.buf[i] = i + '0'; 431 /* Trailing bytes are still %NUL. */ 432 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 433 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 434 435 /* String is terminated, so strnlen() is valid. */ 436 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf)), end); 437 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 438 /* A truncated strnlen() will be safe, too. */ 439 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf) / 2), 440 sizeof(pad.buf) / 2); 441 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 442 443 /* Make string unterminated, and recount. */ 444 pad.buf[end] = 'A'; 445 end = sizeof(pad.buf); 446 /* Reading beyond with strncpy() will fail. */ 447 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 1), end); 448 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 449 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 2), end); 450 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 451 452 /* Early-truncated is safe still, though. */ 453 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 454 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 455 456 end = sizeof(pad.buf) / 2; 457 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 458 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 459 } 460 461 static void fortify_test_strcpy(struct kunit *test) 462 { 463 struct fortify_padding pad = { }; 464 char src[sizeof(pad.buf) + 1] = { }; 465 int i; 466 467 /* Fill 31 bytes with valid characters. */ 468 for (i = 0; i < sizeof(src) - 2; i++) 469 src[i] = i + '0'; 470 471 /* Destination is %NUL-filled to start with. */ 472 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 473 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 474 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 475 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 476 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 477 478 /* Legitimate strcpy() 1 less than of max size. */ 479 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 480 == pad.buf); 481 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 482 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 483 /* Only last byte should be %NUL */ 484 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 485 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 486 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 487 488 src[sizeof(src) - 2] = 'A'; 489 /* But now we trip the overflow checking. */ 490 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 491 == pad.buf); 492 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 493 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 494 /* Trailing %NUL -- thanks to FORTIFY. */ 495 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 496 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 497 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 498 /* And we will not have gone beyond. */ 499 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 500 501 src[sizeof(src) - 1] = 'A'; 502 /* And for sure now, two bytes past. */ 503 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 504 == pad.buf); 505 /* 506 * Which trips both the strlen() on the unterminated src, 507 * and the resulting copy attempt. 508 */ 509 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 510 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 511 /* Trailing %NUL -- thanks to FORTIFY. */ 512 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 513 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 514 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 515 /* And we will not have gone beyond. */ 516 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 517 } 518 519 static void fortify_test_strncpy(struct kunit *test) 520 { 521 struct fortify_padding pad = { }; 522 char src[] = "Copy me fully into a small buffer and I will overflow!"; 523 524 /* Destination is %NUL-filled to start with. */ 525 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 526 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 527 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 528 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 529 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 530 531 /* Legitimate strncpy() 1 less than of max size. */ 532 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 533 sizeof(pad.buf) + unconst - 1) 534 == pad.buf); 535 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 536 /* Only last byte should be %NUL */ 537 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 538 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 539 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 540 541 /* Legitimate (though unterminated) max-size strncpy. */ 542 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 543 sizeof(pad.buf) + unconst) 544 == pad.buf); 545 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 546 /* No trailing %NUL -- thanks strncpy API. */ 547 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 548 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 549 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 550 /* But we will not have gone beyond. */ 551 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 552 553 /* Now verify that FORTIFY is working... */ 554 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 555 sizeof(pad.buf) + unconst + 1) 556 == pad.buf); 557 /* Should catch the overflow. */ 558 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 559 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 560 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 561 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 562 /* And we will not have gone beyond. */ 563 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 564 565 /* And further... */ 566 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 567 sizeof(pad.buf) + unconst + 2) 568 == pad.buf); 569 /* Should catch the overflow. */ 570 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 571 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 572 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 573 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 574 /* And we will not have gone beyond. */ 575 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 576 } 577 578 static void fortify_test_strscpy(struct kunit *test) 579 { 580 struct fortify_padding pad = { }; 581 char src[] = "Copy me fully into a small buffer and I will overflow!"; 582 583 /* Destination is %NUL-filled to start with. */ 584 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 585 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 586 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 587 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 588 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 589 590 /* Legitimate strscpy() 1 less than of max size. */ 591 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 592 sizeof(pad.buf) + unconst - 1), 593 -E2BIG); 594 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 595 /* Keeping space for %NUL, last two bytes should be %NUL */ 596 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 597 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 598 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 599 600 /* Legitimate max-size strscpy. */ 601 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 602 sizeof(pad.buf) + unconst), 603 -E2BIG); 604 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 605 /* A trailing %NUL will exist. */ 606 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 607 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 608 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 609 610 /* Now verify that FORTIFY is working... */ 611 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 612 sizeof(pad.buf) + unconst + 1), 613 -E2BIG); 614 /* Should catch the overflow. */ 615 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 616 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 617 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 618 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 619 /* And we will not have gone beyond. */ 620 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 621 622 /* And much further... */ 623 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 624 sizeof(src) * 2 + unconst), 625 -E2BIG); 626 /* Should catch the overflow. */ 627 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 628 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 629 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 630 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 631 /* And we will not have gone beyond. */ 632 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 633 } 634 635 static void fortify_test_strcat(struct kunit *test) 636 { 637 struct fortify_padding pad = { }; 638 char src[sizeof(pad.buf) / 2] = { }; 639 char one[] = "A"; 640 char two[] = "BC"; 641 int i; 642 643 /* Fill 15 bytes with valid characters. */ 644 for (i = 0; i < sizeof(src) - 1; i++) 645 src[i] = i + 'A'; 646 647 /* Destination is %NUL-filled to start with. */ 648 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 649 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 650 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 651 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 652 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 653 654 /* Legitimate strcat() using less than half max size. */ 655 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 656 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 657 /* Legitimate strcat() now 2 bytes shy of end. */ 658 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 659 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 660 /* Last two bytes should be %NUL */ 661 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 662 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 663 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 664 665 /* Add one more character to the end. */ 666 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 667 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 668 /* Last byte should be %NUL */ 669 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 670 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 671 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 672 673 /* And this one char will overflow. */ 674 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 675 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 676 /* Last byte should be %NUL thanks to FORTIFY. */ 677 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 678 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 679 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 680 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 681 682 /* And adding two will overflow more. */ 683 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, two) == pad.buf); 684 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 685 /* Last byte should be %NUL thanks to FORTIFY. */ 686 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 687 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 688 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 689 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 690 } 691 692 static void fortify_test_strncat(struct kunit *test) 693 { 694 struct fortify_padding pad = { }; 695 char src[sizeof(pad.buf)] = { }; 696 int i, partial; 697 698 /* Fill 31 bytes with valid characters. */ 699 partial = sizeof(src) / 2 - 1; 700 for (i = 0; i < partial; i++) 701 src[i] = i + 'A'; 702 703 /* Destination is %NUL-filled to start with. */ 704 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 705 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 706 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 707 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 708 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 709 710 /* Legitimate strncat() using less than half max size. */ 711 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 712 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 713 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 714 /* Legitimate strncat() now 2 bytes shy of end. */ 715 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 716 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 717 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 718 /* Last two bytes should be %NUL */ 719 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 720 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 721 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 722 723 /* Add one more character to the end. */ 724 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 725 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 726 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 727 /* Last byte should be %NUL */ 728 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 729 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 730 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 731 732 /* And this one char will overflow. */ 733 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 734 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 735 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 736 /* Last byte should be %NUL thanks to FORTIFY. */ 737 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 738 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 739 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 740 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 741 742 /* And adding two will overflow more. */ 743 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 2) == pad.buf); 744 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 745 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 746 /* Last byte should be %NUL thanks to FORTIFY. */ 747 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 748 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 749 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 750 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 751 752 /* Force an unterminated destination, and overflow. */ 753 pad.buf[sizeof(pad.buf) - 1] = 'A'; 754 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 755 /* This will have tripped both strlen() and strcat(). */ 756 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 757 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 758 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 759 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 760 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 761 /* But we should not go beyond the end. */ 762 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 763 } 764 765 static void fortify_test_strlcat(struct kunit *test) 766 { 767 struct fortify_padding pad = { }; 768 char src[sizeof(pad.buf)] = { }; 769 int i, partial; 770 int len = sizeof(pad.buf) + unconst; 771 772 /* Fill 15 bytes with valid characters. */ 773 partial = sizeof(src) / 2 - 1; 774 for (i = 0; i < partial; i++) 775 src[i] = i + 'A'; 776 777 /* Destination is %NUL-filled to start with. */ 778 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 779 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 780 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 781 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 782 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 783 784 /* Legitimate strlcat() using less than half max size. */ 785 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial); 786 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 787 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 788 /* Legitimate strlcat() now 2 bytes shy of end. */ 789 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial * 2); 790 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 791 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 792 /* Last two bytes should be %NUL */ 793 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 794 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 795 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 796 797 /* Add one more character to the end. */ 798 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "Q", len), partial * 2 + 1); 799 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 800 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 801 /* Last byte should be %NUL */ 802 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 803 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 804 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 805 806 /* And this one char will overflow. */ 807 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "V", len * 2), len); 808 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 809 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 810 /* Last byte should be %NUL thanks to FORTIFY. */ 811 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 812 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 813 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 814 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 815 816 /* And adding two will overflow more. */ 817 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "QQ", len * 2), len + 1); 818 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 819 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 820 /* Last byte should be %NUL thanks to FORTIFY. */ 821 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 822 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 823 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 824 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 825 826 /* Force an unterminated destination, and overflow. */ 827 pad.buf[sizeof(pad.buf) - 1] = 'A'; 828 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "TT", len * 2), len + 2); 829 /* This will have tripped both strlen() and strlcat(). */ 830 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 831 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 832 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 833 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 834 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 835 /* But we should not go beyond the end. */ 836 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 837 838 /* Force an unterminated source, and overflow. */ 839 memset(src, 'B', sizeof(src)); 840 pad.buf[sizeof(pad.buf) - 1] = '\0'; 841 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len * 3), len - 1 + sizeof(src)); 842 /* This will have tripped both strlen() and strlcat(). */ 843 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 844 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 845 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 846 /* But we should not go beyond the end. */ 847 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 848 } 849 850 /* Check for 0-sized arrays... */ 851 struct fortify_zero_sized { 852 unsigned long bytes_before; 853 char buf[0]; 854 unsigned long bytes_after; 855 }; 856 857 #define __fortify_test(memfunc) \ 858 static void fortify_test_##memfunc(struct kunit *test) \ 859 { \ 860 struct fortify_zero_sized zero = { }; \ 861 struct fortify_padding pad = { }; \ 862 char srcA[sizeof(pad.buf) + 2]; \ 863 char srcB[sizeof(pad.buf) + 2]; \ 864 size_t len = sizeof(pad.buf) + unconst; \ 865 \ 866 memset(srcA, 'A', sizeof(srcA)); \ 867 KUNIT_ASSERT_EQ(test, srcA[0], 'A'); \ 868 memset(srcB, 'B', sizeof(srcB)); \ 869 KUNIT_ASSERT_EQ(test, srcB[0], 'B'); \ 870 \ 871 memfunc(pad.buf, srcA, 0 + unconst); \ 872 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 873 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 874 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 875 memfunc(pad.buf + 1, srcB, 1 + unconst); \ 876 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 877 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 878 KUNIT_EXPECT_EQ(test, pad.buf[2], '\0'); \ 879 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 880 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 881 memfunc(pad.buf, srcA, 1 + unconst); \ 882 KUNIT_EXPECT_EQ(test, pad.buf[0], 'A'); \ 883 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 884 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 885 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 886 memfunc(pad.buf, srcA, len - 1); \ 887 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 888 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], '\0'); \ 889 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 890 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 891 memfunc(pad.buf, srcA, len); \ 892 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 893 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], 'A'); \ 894 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); \ 895 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 896 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 897 memfunc(pad.buf, srcA, len + 1); \ 898 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 899 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \ 900 memfunc(pad.buf + 1, srcB, len); \ 901 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 902 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); \ 903 \ 904 /* Reset error counter. */ \ 905 fortify_write_overflows = 0; \ 906 /* Copy nothing into nothing: no errors. */ \ 907 memfunc(zero.buf, srcB, 0 + unconst); \ 908 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 909 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 910 memfunc(zero.buf, srcB, 1 + unconst); \ 911 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 912 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \ 913 } 914 __fortify_test(memcpy) 915 __fortify_test(memmove) 916 917 static void fortify_test_memscan(struct kunit *test) 918 { 919 char haystack[] = "Where oh where is my memory range?"; 920 char *mem = haystack + strlen("Where oh where is "); 921 char needle = 'm'; 922 size_t len = sizeof(haystack) + unconst; 923 924 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len), 925 mem); 926 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 927 /* Catch too-large range. */ 928 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len + 1), 929 NULL); 930 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 931 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len * 2), 932 NULL); 933 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 934 } 935 936 static void fortify_test_memchr(struct kunit *test) 937 { 938 char haystack[] = "Where oh where is my memory range?"; 939 char *mem = haystack + strlen("Where oh where is "); 940 char needle = 'm'; 941 size_t len = sizeof(haystack) + unconst; 942 943 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len), 944 mem); 945 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 946 /* Catch too-large range. */ 947 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len + 1), 948 NULL); 949 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 950 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len * 2), 951 NULL); 952 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 953 } 954 955 static void fortify_test_memchr_inv(struct kunit *test) 956 { 957 char haystack[] = "Where oh where is my memory range?"; 958 char *mem = haystack + 1; 959 char needle = 'W'; 960 size_t len = sizeof(haystack) + unconst; 961 962 /* Normal search is okay. */ 963 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len), 964 mem); 965 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 966 /* Catch too-large range. */ 967 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len + 1), 968 NULL); 969 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 970 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len * 2), 971 NULL); 972 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 973 } 974 975 static void fortify_test_memcmp(struct kunit *test) 976 { 977 char one[] = "My mind is going ..."; 978 char two[] = "My mind is going ... I can feel it."; 979 size_t one_len = sizeof(one) + unconst - 1; 980 size_t two_len = sizeof(two) + unconst - 1; 981 982 /* We match the first string (ignoring the %NUL). */ 983 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len), 0); 984 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 985 /* Still in bounds, but no longer matching. */ 986 KUNIT_ASSERT_LT(test, memcmp(one, two, one_len + 1), 0); 987 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 988 989 /* Catch too-large ranges. */ 990 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 2), INT_MIN); 991 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 992 993 KUNIT_ASSERT_EQ(test, memcmp(two, one, two_len + 2), INT_MIN); 994 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 995 } 996 997 static void fortify_test_kmemdup(struct kunit *test) 998 { 999 char src[] = "I got Doom running on it!"; 1000 char *copy; 1001 size_t len = sizeof(src) + unconst; 1002 1003 /* Copy is within bounds. */ 1004 copy = kmemdup(src, len, GFP_KERNEL); 1005 KUNIT_EXPECT_NOT_NULL(test, copy); 1006 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1007 kfree(copy); 1008 1009 /* Without %NUL. */ 1010 copy = kmemdup(src, len - 1, GFP_KERNEL); 1011 KUNIT_EXPECT_NOT_NULL(test, copy); 1012 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1013 kfree(copy); 1014 1015 /* Tiny bounds. */ 1016 copy = kmemdup(src, 1, GFP_KERNEL); 1017 KUNIT_EXPECT_NOT_NULL(test, copy); 1018 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1019 kfree(copy); 1020 1021 /* Out of bounds by 1 byte. */ 1022 copy = kmemdup(src, len + 1, GFP_KERNEL); 1023 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1024 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 1025 kfree(copy); 1026 1027 /* Way out of bounds. */ 1028 copy = kmemdup(src, len * 2, GFP_KERNEL); 1029 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1030 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 1031 kfree(copy); 1032 1033 /* Starting offset causing out of bounds. */ 1034 copy = kmemdup(src + 1, len, GFP_KERNEL); 1035 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1036 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 1037 kfree(copy); 1038 } 1039 1040 static int fortify_test_init(struct kunit *test) 1041 { 1042 if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) 1043 kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); 1044 1045 fortify_read_overflows = 0; 1046 kunit_add_named_resource(test, NULL, NULL, &read_resource, 1047 "fortify_read_overflows", 1048 &fortify_read_overflows); 1049 fortify_write_overflows = 0; 1050 kunit_add_named_resource(test, NULL, NULL, &write_resource, 1051 "fortify_write_overflows", 1052 &fortify_write_overflows); 1053 return 0; 1054 } 1055 1056 static struct kunit_case fortify_test_cases[] = { 1057 KUNIT_CASE(fortify_test_known_sizes), 1058 KUNIT_CASE(fortify_test_control_flow_split), 1059 KUNIT_CASE(fortify_test_alloc_size_kmalloc_const), 1060 KUNIT_CASE(fortify_test_alloc_size_kmalloc_dynamic), 1061 KUNIT_CASE(fortify_test_alloc_size_vmalloc_const), 1062 KUNIT_CASE(fortify_test_alloc_size_vmalloc_dynamic), 1063 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_const), 1064 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_dynamic), 1065 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_const), 1066 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_dynamic), 1067 KUNIT_CASE(fortify_test_realloc_size), 1068 KUNIT_CASE(fortify_test_strlen), 1069 KUNIT_CASE(fortify_test_strnlen), 1070 KUNIT_CASE(fortify_test_strcpy), 1071 KUNIT_CASE(fortify_test_strncpy), 1072 KUNIT_CASE(fortify_test_strscpy), 1073 KUNIT_CASE(fortify_test_strcat), 1074 KUNIT_CASE(fortify_test_strncat), 1075 KUNIT_CASE(fortify_test_strlcat), 1076 /* skip memset: performs bounds checking on whole structs */ 1077 KUNIT_CASE(fortify_test_memcpy), 1078 KUNIT_CASE(fortify_test_memmove), 1079 KUNIT_CASE(fortify_test_memscan), 1080 KUNIT_CASE(fortify_test_memchr), 1081 KUNIT_CASE(fortify_test_memchr_inv), 1082 KUNIT_CASE(fortify_test_memcmp), 1083 KUNIT_CASE(fortify_test_kmemdup), 1084 {} 1085 }; 1086 1087 static struct kunit_suite fortify_test_suite = { 1088 .name = "fortify", 1089 .init = fortify_test_init, 1090 .test_cases = fortify_test_cases, 1091 }; 1092 1093 kunit_test_suite(fortify_test_suite); 1094 1095 MODULE_DESCRIPTION("Runtime test cases for CONFIG_FORTIFY_SOURCE"); 1096 MODULE_LICENSE("GPL"); 1097