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, prev_size, \ 310 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 311 kvfree(p)); \ 312 } while (0) 313 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 314 315 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 316 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 317 const char dev_name[] = "fortify-test"; \ 318 struct device *dev; \ 319 void *orig; \ 320 size_t len; \ 321 \ 322 /* Create dummy device for devm_kmalloc()-family tests. */ \ 323 dev = kunit_device_register(test, dev_name); \ 324 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 325 "Cannot register test device\n"); \ 326 \ 327 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 328 devm_kfree(dev, p)); \ 329 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 330 devm_kfree(dev, p)); \ 331 checker(expected_size, \ 332 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 333 devm_kfree(dev, p)); \ 334 checker(expected_size, \ 335 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 336 devm_kfree(dev, p)); \ 337 checker(expected_size, \ 338 devm_kcalloc(dev, 1, alloc_size, gfp), \ 339 devm_kfree(dev, p)); \ 340 checker(expected_size, \ 341 devm_kcalloc(dev, alloc_size, 1, gfp), \ 342 devm_kfree(dev, p)); \ 343 \ 344 orig = devm_kmalloc(dev, alloc_size, gfp); \ 345 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 346 checker((expected_size) * 2, \ 347 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 348 devm_kfree(dev, p)); \ 349 \ 350 len = 4; \ 351 /* Using memdup() with fixed size, so force unknown length. */ \ 352 if (!__builtin_constant_p(expected_size)) \ 353 len += zero_size; \ 354 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 355 devm_kfree(dev, p)); \ 356 \ 357 kunit_device_unregister(test, dev); \ 358 } while (0) 359 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 360 361 static const char * const test_strs[] = { 362 "", 363 "Hello there", 364 "A longer string, just for variety", 365 }; 366 367 #define TEST_realloc(checker) do { \ 368 gfp_t gfp = GFP_KERNEL; \ 369 size_t len; \ 370 int i; \ 371 \ 372 for (i = 0; i < ARRAY_SIZE(test_strs); i++) { \ 373 len = strlen(test_strs[i]); \ 374 KUNIT_EXPECT_EQ(test, __builtin_constant_p(len), 0); \ 375 checker(len, kmemdup_array(test_strs[i], 1, len, gfp), \ 376 kfree(p)); \ 377 checker(len, kmemdup(test_strs[i], len, gfp), \ 378 kfree(p)); \ 379 } \ 380 } while (0) 381 static void fortify_test_realloc_size(struct kunit *test) 382 { 383 TEST_realloc(check_dynamic); 384 } 385 386 /* 387 * We can't have an array at the end of a structure or else 388 * builds without -fstrict-flex-arrays=3 will report them as 389 * being an unknown length. Additionally, add bytes before 390 * and after the string to catch over/underflows if tests 391 * fail. 392 */ 393 struct fortify_padding { 394 unsigned long bytes_before; 395 char buf[32]; 396 unsigned long bytes_after; 397 }; 398 /* Force compiler into not being able to resolve size at compile-time. */ 399 static volatile int unconst; 400 401 static void fortify_test_strlen(struct kunit *test) 402 { 403 struct fortify_padding pad = { }; 404 int i, end = sizeof(pad.buf) - 1; 405 406 /* Fill 31 bytes with valid characters. */ 407 for (i = 0; i < sizeof(pad.buf) - 1; i++) 408 pad.buf[i] = i + '0'; 409 /* Trailing bytes are still %NUL. */ 410 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 411 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 412 413 /* String is terminated, so strlen() is valid. */ 414 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 415 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 416 417 /* Make string unterminated, and recount. */ 418 pad.buf[end] = 'A'; 419 end = sizeof(pad.buf); 420 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 421 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 422 } 423 424 static void fortify_test_strnlen(struct kunit *test) 425 { 426 struct fortify_padding pad = { }; 427 int i, end = sizeof(pad.buf) - 1; 428 429 /* Fill 31 bytes with valid characters. */ 430 for (i = 0; i < sizeof(pad.buf) - 1; i++) 431 pad.buf[i] = i + '0'; 432 /* Trailing bytes are still %NUL. */ 433 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 434 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 435 436 /* String is terminated, so strnlen() is valid. */ 437 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf)), end); 438 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 439 /* A truncated strnlen() will be safe, too. */ 440 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf) / 2), 441 sizeof(pad.buf) / 2); 442 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 443 444 /* Make string unterminated, and recount. */ 445 pad.buf[end] = 'A'; 446 end = sizeof(pad.buf); 447 /* Reading beyond with strncpy() will fail. */ 448 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 1), end); 449 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 450 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 2), end); 451 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 452 453 /* Early-truncated is safe still, though. */ 454 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 455 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 456 457 end = sizeof(pad.buf) / 2; 458 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 459 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 460 } 461 462 static void fortify_test_strcpy(struct kunit *test) 463 { 464 struct fortify_padding pad = { }; 465 char src[sizeof(pad.buf) + 1] = { }; 466 int i; 467 468 /* Fill 31 bytes with valid characters. */ 469 for (i = 0; i < sizeof(src) - 2; i++) 470 src[i] = i + '0'; 471 472 /* Destination is %NUL-filled to start with. */ 473 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 474 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 475 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 476 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 477 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 478 479 /* Legitimate strcpy() 1 less than of max size. */ 480 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 481 == pad.buf); 482 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 483 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 484 /* Only last byte should be %NUL */ 485 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 486 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 487 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 488 489 src[sizeof(src) - 2] = 'A'; 490 /* But now we trip the overflow checking. */ 491 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 492 == pad.buf); 493 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 494 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 495 /* Trailing %NUL -- thanks to FORTIFY. */ 496 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 497 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 498 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 499 /* And we will not have gone beyond. */ 500 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 501 502 src[sizeof(src) - 1] = 'A'; 503 /* And for sure now, two bytes past. */ 504 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 505 == pad.buf); 506 /* 507 * Which trips both the strlen() on the unterminated src, 508 * and the resulting copy attempt. 509 */ 510 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 511 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 512 /* Trailing %NUL -- thanks to FORTIFY. */ 513 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 514 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 515 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 516 /* And we will not have gone beyond. */ 517 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 518 } 519 520 static void fortify_test_strncpy(struct kunit *test) 521 { 522 struct fortify_padding pad = { }; 523 char src[] = "Copy me fully into a small buffer and I will overflow!"; 524 525 /* Destination is %NUL-filled to start with. */ 526 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 527 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 528 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 529 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 530 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 531 532 /* Legitimate strncpy() 1 less than of max size. */ 533 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 534 sizeof(pad.buf) + unconst - 1) 535 == pad.buf); 536 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 537 /* Only last byte should be %NUL */ 538 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 539 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 540 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 541 542 /* Legitimate (though unterminated) max-size strncpy. */ 543 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 544 sizeof(pad.buf) + unconst) 545 == pad.buf); 546 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 547 /* No trailing %NUL -- thanks strncpy API. */ 548 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 549 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 550 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 551 /* But we will not have gone beyond. */ 552 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 553 554 /* Now verify that FORTIFY is working... */ 555 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 556 sizeof(pad.buf) + unconst + 1) 557 == pad.buf); 558 /* Should catch the overflow. */ 559 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 560 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 561 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 562 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 563 /* And we will not have gone beyond. */ 564 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 565 566 /* And further... */ 567 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 568 sizeof(pad.buf) + unconst + 2) 569 == pad.buf); 570 /* Should catch the overflow. */ 571 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 572 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 573 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 574 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 575 /* And we will not have gone beyond. */ 576 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 577 } 578 579 static void fortify_test_strscpy(struct kunit *test) 580 { 581 struct fortify_padding pad = { }; 582 char src[] = "Copy me fully into a small buffer and I will overflow!"; 583 584 /* Destination is %NUL-filled to start with. */ 585 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 586 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 587 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 588 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 589 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 590 591 /* Legitimate strscpy() 1 less than of max size. */ 592 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 593 sizeof(pad.buf) + unconst - 1), 594 -E2BIG); 595 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 596 /* Keeping space for %NUL, last two bytes should be %NUL */ 597 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 598 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 599 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 600 601 /* Legitimate max-size strscpy. */ 602 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 603 sizeof(pad.buf) + unconst), 604 -E2BIG); 605 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 606 /* A trailing %NUL will exist. */ 607 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 608 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 609 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 610 611 /* Now verify that FORTIFY is working... */ 612 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 613 sizeof(pad.buf) + unconst + 1), 614 -E2BIG); 615 /* Should catch the overflow. */ 616 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 617 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 618 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 619 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 620 /* And we will not have gone beyond. */ 621 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 622 623 /* And much further... */ 624 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 625 sizeof(src) * 2 + unconst), 626 -E2BIG); 627 /* Should catch the overflow. */ 628 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 629 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 630 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 631 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 632 /* And we will not have gone beyond. */ 633 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 634 } 635 636 static void fortify_test_strcat(struct kunit *test) 637 { 638 struct fortify_padding pad = { }; 639 char src[sizeof(pad.buf) / 2] = { }; 640 char one[] = "A"; 641 char two[] = "BC"; 642 int i; 643 644 /* Fill 15 bytes with valid characters. */ 645 for (i = 0; i < sizeof(src) - 1; i++) 646 src[i] = i + 'A'; 647 648 /* Destination is %NUL-filled to start with. */ 649 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 650 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 651 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 652 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 653 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 654 655 /* Legitimate strcat() using less than half max size. */ 656 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 657 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 658 /* Legitimate strcat() now 2 bytes shy of end. */ 659 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 660 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 661 /* Last two bytes should be %NUL */ 662 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 663 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 664 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 665 666 /* Add one more character to the end. */ 667 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 668 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 669 /* Last byte should be %NUL */ 670 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 671 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 672 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 673 674 /* And this one char will overflow. */ 675 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 676 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 677 /* Last byte should be %NUL thanks to FORTIFY. */ 678 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 679 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 680 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 681 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 682 683 /* And adding two will overflow more. */ 684 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, two) == pad.buf); 685 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 686 /* Last byte should be %NUL thanks to FORTIFY. */ 687 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 688 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 689 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 690 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 691 } 692 693 static void fortify_test_strncat(struct kunit *test) 694 { 695 struct fortify_padding pad = { }; 696 char src[sizeof(pad.buf)] = { }; 697 int i, partial; 698 699 /* Fill 31 bytes with valid characters. */ 700 partial = sizeof(src) / 2 - 1; 701 for (i = 0; i < partial; i++) 702 src[i] = i + 'A'; 703 704 /* Destination is %NUL-filled to start with. */ 705 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 706 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 707 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 708 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 709 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 710 711 /* Legitimate strncat() using less than half max size. */ 712 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 713 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 714 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 715 /* Legitimate strncat() now 2 bytes shy of end. */ 716 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 717 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 718 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 719 /* Last two bytes should be %NUL */ 720 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 721 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 722 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 723 724 /* Add one more character to the end. */ 725 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 726 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 727 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 728 /* Last byte should be %NUL */ 729 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 730 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 731 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 732 733 /* And this one char will overflow. */ 734 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 735 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 736 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 737 /* Last byte should be %NUL thanks to FORTIFY. */ 738 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 739 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 740 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 741 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 742 743 /* And adding two will overflow more. */ 744 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 2) == pad.buf); 745 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 746 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 747 /* Last byte should be %NUL thanks to FORTIFY. */ 748 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 749 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 750 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 751 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 752 753 /* Force an unterminated destination, and overflow. */ 754 pad.buf[sizeof(pad.buf) - 1] = 'A'; 755 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 756 /* This will have tripped both strlen() and strcat(). */ 757 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 758 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 759 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 760 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 761 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 762 /* But we should not go beyond the end. */ 763 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 764 } 765 766 static void fortify_test_strlcat(struct kunit *test) 767 { 768 struct fortify_padding pad = { }; 769 char src[sizeof(pad.buf)] = { }; 770 int i, partial; 771 int len = sizeof(pad.buf) + unconst; 772 773 /* Fill 15 bytes with valid characters. */ 774 partial = sizeof(src) / 2 - 1; 775 for (i = 0; i < partial; i++) 776 src[i] = i + 'A'; 777 778 /* Destination is %NUL-filled to start with. */ 779 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 780 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 781 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 782 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 783 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 784 785 /* Legitimate strlcat() using less than half max size. */ 786 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial); 787 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 788 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 789 /* Legitimate strlcat() now 2 bytes shy of end. */ 790 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial * 2); 791 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 792 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 793 /* Last two bytes should be %NUL */ 794 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 795 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 796 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 797 798 /* Add one more character to the end. */ 799 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "Q", len), partial * 2 + 1); 800 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 801 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 802 /* Last byte should be %NUL */ 803 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 804 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 805 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 806 807 /* And this one char will overflow. */ 808 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "V", len * 2), len); 809 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 810 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 811 /* Last byte should be %NUL thanks to FORTIFY. */ 812 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 813 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 814 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 815 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 816 817 /* And adding two will overflow more. */ 818 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "QQ", len * 2), len + 1); 819 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 820 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 821 /* Last byte should be %NUL thanks to FORTIFY. */ 822 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 823 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 824 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 825 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 826 827 /* Force an unterminated destination, and overflow. */ 828 pad.buf[sizeof(pad.buf) - 1] = 'A'; 829 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "TT", len * 2), len + 2); 830 /* This will have tripped both strlen() and strlcat(). */ 831 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 832 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 833 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 834 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 835 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 836 /* But we should not go beyond the end. */ 837 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 838 839 /* Force an unterminated source, and overflow. */ 840 memset(src, 'B', sizeof(src)); 841 pad.buf[sizeof(pad.buf) - 1] = '\0'; 842 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len * 3), len - 1 + sizeof(src)); 843 /* This will have tripped both strlen() and strlcat(). */ 844 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 845 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 846 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 847 /* But we should not go beyond the end. */ 848 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 849 } 850 851 /* Check for 0-sized arrays... */ 852 struct fortify_zero_sized { 853 unsigned long bytes_before; 854 char buf[0]; 855 unsigned long bytes_after; 856 }; 857 858 #define __fortify_test(memfunc) \ 859 static void fortify_test_##memfunc(struct kunit *test) \ 860 { \ 861 struct fortify_zero_sized zero = { }; \ 862 struct fortify_padding pad = { }; \ 863 char srcA[sizeof(pad.buf) + 2]; \ 864 char srcB[sizeof(pad.buf) + 2]; \ 865 size_t len = sizeof(pad.buf) + unconst; \ 866 \ 867 memset(srcA, 'A', sizeof(srcA)); \ 868 KUNIT_ASSERT_EQ(test, srcA[0], 'A'); \ 869 memset(srcB, 'B', sizeof(srcB)); \ 870 KUNIT_ASSERT_EQ(test, srcB[0], 'B'); \ 871 \ 872 memfunc(pad.buf, srcA, 0 + unconst); \ 873 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 874 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 875 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 876 memfunc(pad.buf + 1, srcB, 1 + unconst); \ 877 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 878 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 879 KUNIT_EXPECT_EQ(test, pad.buf[2], '\0'); \ 880 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 881 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 882 memfunc(pad.buf, srcA, 1 + unconst); \ 883 KUNIT_EXPECT_EQ(test, pad.buf[0], 'A'); \ 884 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 885 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 886 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 887 memfunc(pad.buf, srcA, len - 1); \ 888 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 889 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], '\0'); \ 890 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 891 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 892 memfunc(pad.buf, srcA, len); \ 893 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 894 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], 'A'); \ 895 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); \ 896 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 897 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 898 memfunc(pad.buf, srcA, len + 1); \ 899 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 900 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \ 901 memfunc(pad.buf + 1, srcB, len); \ 902 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 903 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); \ 904 \ 905 /* Reset error counter. */ \ 906 fortify_write_overflows = 0; \ 907 /* Copy nothing into nothing: no errors. */ \ 908 memfunc(zero.buf, srcB, 0 + unconst); \ 909 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 910 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 911 memfunc(zero.buf, srcB, 1 + unconst); \ 912 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 913 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \ 914 } 915 __fortify_test(memcpy) 916 __fortify_test(memmove) 917 918 static void fortify_test_memscan(struct kunit *test) 919 { 920 char haystack[] = "Where oh where is my memory range?"; 921 char *mem = haystack + strlen("Where oh where is "); 922 char needle = 'm'; 923 size_t len = sizeof(haystack) + unconst; 924 925 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len), 926 mem); 927 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 928 /* Catch too-large range. */ 929 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len + 1), 930 NULL); 931 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 932 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len * 2), 933 NULL); 934 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 935 } 936 937 static void fortify_test_memchr(struct kunit *test) 938 { 939 char haystack[] = "Where oh where is my memory range?"; 940 char *mem = haystack + strlen("Where oh where is "); 941 char needle = 'm'; 942 size_t len = sizeof(haystack) + unconst; 943 944 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len), 945 mem); 946 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 947 /* Catch too-large range. */ 948 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len + 1), 949 NULL); 950 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 951 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len * 2), 952 NULL); 953 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 954 } 955 956 static void fortify_test_memchr_inv(struct kunit *test) 957 { 958 char haystack[] = "Where oh where is my memory range?"; 959 char *mem = haystack + 1; 960 char needle = 'W'; 961 size_t len = sizeof(haystack) + unconst; 962 963 /* Normal search is okay. */ 964 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len), 965 mem); 966 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 967 /* Catch too-large range. */ 968 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len + 1), 969 NULL); 970 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 971 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len * 2), 972 NULL); 973 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 974 } 975 976 static void fortify_test_memcmp(struct kunit *test) 977 { 978 char one[] = "My mind is going ..."; 979 char two[] = "My mind is going ... I can feel it."; 980 size_t one_len = sizeof(one) + unconst - 1; 981 size_t two_len = sizeof(two) + unconst - 1; 982 983 /* We match the first string (ignoring the %NUL). */ 984 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len), 0); 985 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 986 /* Still in bounds, but no longer matching. */ 987 KUNIT_ASSERT_LT(test, memcmp(one, two, one_len + 1), 0); 988 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 989 990 /* Catch too-large ranges. */ 991 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 2), INT_MIN); 992 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 993 994 KUNIT_ASSERT_EQ(test, memcmp(two, one, two_len + 2), INT_MIN); 995 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 996 } 997 998 static void fortify_test_kmemdup(struct kunit *test) 999 { 1000 char src[] = "I got Doom running on it!"; 1001 char *copy; 1002 size_t len = sizeof(src) + unconst; 1003 1004 /* Copy is within bounds. */ 1005 copy = kmemdup(src, len, GFP_KERNEL); 1006 KUNIT_EXPECT_NOT_NULL(test, copy); 1007 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1008 kfree(copy); 1009 1010 /* Without %NUL. */ 1011 copy = kmemdup(src, len - 1, GFP_KERNEL); 1012 KUNIT_EXPECT_NOT_NULL(test, copy); 1013 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1014 kfree(copy); 1015 1016 /* Tiny bounds. */ 1017 copy = kmemdup(src, 1, GFP_KERNEL); 1018 KUNIT_EXPECT_NOT_NULL(test, copy); 1019 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1020 kfree(copy); 1021 1022 /* Out of bounds by 1 byte. */ 1023 copy = kmemdup(src, len + 1, GFP_KERNEL); 1024 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1025 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 1026 kfree(copy); 1027 1028 /* Way out of bounds. */ 1029 copy = kmemdup(src, len * 2, GFP_KERNEL); 1030 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1031 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 1032 kfree(copy); 1033 1034 /* Starting offset causing out of bounds. */ 1035 copy = kmemdup(src + 1, len, GFP_KERNEL); 1036 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1037 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 1038 kfree(copy); 1039 } 1040 1041 static int fortify_test_init(struct kunit *test) 1042 { 1043 if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) 1044 kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); 1045 1046 fortify_read_overflows = 0; 1047 kunit_add_named_resource(test, NULL, NULL, &read_resource, 1048 "fortify_read_overflows", 1049 &fortify_read_overflows); 1050 fortify_write_overflows = 0; 1051 kunit_add_named_resource(test, NULL, NULL, &write_resource, 1052 "fortify_write_overflows", 1053 &fortify_write_overflows); 1054 return 0; 1055 } 1056 1057 static struct kunit_case fortify_test_cases[] = { 1058 KUNIT_CASE(fortify_test_known_sizes), 1059 KUNIT_CASE(fortify_test_control_flow_split), 1060 KUNIT_CASE(fortify_test_alloc_size_kmalloc_const), 1061 KUNIT_CASE(fortify_test_alloc_size_kmalloc_dynamic), 1062 KUNIT_CASE(fortify_test_alloc_size_vmalloc_const), 1063 KUNIT_CASE(fortify_test_alloc_size_vmalloc_dynamic), 1064 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_const), 1065 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_dynamic), 1066 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_const), 1067 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_dynamic), 1068 KUNIT_CASE(fortify_test_realloc_size), 1069 KUNIT_CASE(fortify_test_strlen), 1070 KUNIT_CASE(fortify_test_strnlen), 1071 KUNIT_CASE(fortify_test_strcpy), 1072 KUNIT_CASE(fortify_test_strncpy), 1073 KUNIT_CASE(fortify_test_strscpy), 1074 KUNIT_CASE(fortify_test_strcat), 1075 KUNIT_CASE(fortify_test_strncat), 1076 KUNIT_CASE(fortify_test_strlcat), 1077 /* skip memset: performs bounds checking on whole structs */ 1078 KUNIT_CASE(fortify_test_memcpy), 1079 KUNIT_CASE(fortify_test_memmove), 1080 KUNIT_CASE(fortify_test_memscan), 1081 KUNIT_CASE(fortify_test_memchr), 1082 KUNIT_CASE(fortify_test_memchr_inv), 1083 KUNIT_CASE(fortify_test_memcmp), 1084 KUNIT_CASE(fortify_test_kmemdup), 1085 {} 1086 }; 1087 1088 static struct kunit_suite fortify_test_suite = { 1089 .name = "fortify", 1090 .init = fortify_test_init, 1091 .test_cases = fortify_test_cases, 1092 }; 1093 1094 kunit_test_suite(fortify_test_suite); 1095 1096 MODULE_DESCRIPTION("Runtime test cases for CONFIG_FORTIFY_SOURCE"); 1097 MODULE_LICENSE("GPL"); 1098