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 checker(expected_size, __kmalloc(alloc_size, gfp), \ 238 kfree(p)); \ 239 \ 240 orig = kmalloc(alloc_size, gfp); \ 241 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 242 checker((expected_size) * 2, \ 243 krealloc(orig, (alloc_size) * 2, gfp), \ 244 kfree(p)); \ 245 orig = kmalloc(alloc_size, gfp); \ 246 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 247 checker((expected_size) * 2, \ 248 krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ 249 kfree(p)); \ 250 orig = kmalloc(alloc_size, gfp); \ 251 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 252 checker((expected_size) * 2, \ 253 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ 254 kfree(p)); \ 255 \ 256 len = 11; \ 257 /* Using memdup() with fixed size, so force unknown length. */ \ 258 if (!__builtin_constant_p(expected_size)) \ 259 len += zero_size; \ 260 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ 261 } while (0) 262 DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) 263 264 /* Sizes are in pages, not bytes. */ 265 #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ 266 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 267 checker((expected_pages) * PAGE_SIZE, \ 268 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 269 checker((expected_pages) * PAGE_SIZE, \ 270 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 271 checker((expected_pages) * PAGE_SIZE, \ 272 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ 273 } while (0) 274 DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) 275 276 /* Sizes are in pages (and open-coded for side-effects), not bytes. */ 277 #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ 278 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 279 size_t prev_size; \ 280 void *orig; \ 281 \ 282 checker((expected_pages) * PAGE_SIZE, \ 283 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ 284 kvfree(p)); \ 285 checker((expected_pages) * PAGE_SIZE, \ 286 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 287 kvfree(p)); \ 288 checker((expected_pages) * PAGE_SIZE, \ 289 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ 290 kvfree(p)); \ 291 checker((expected_pages) * PAGE_SIZE, \ 292 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 293 kvfree(p)); \ 294 checker((expected_pages) * PAGE_SIZE, \ 295 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ 296 kvfree(p)); \ 297 checker((expected_pages) * PAGE_SIZE, \ 298 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ 299 kvfree(p)); \ 300 checker((expected_pages) * PAGE_SIZE, \ 301 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ 302 kvfree(p)); \ 303 checker((expected_pages) * PAGE_SIZE, \ 304 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ 305 kvfree(p)); \ 306 \ 307 prev_size = (expected_pages) * PAGE_SIZE; \ 308 orig = kvmalloc(prev_size, gfp); \ 309 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 310 checker(((expected_pages) * PAGE_SIZE) * 2, \ 311 kvrealloc(orig, prev_size, \ 312 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 313 kvfree(p)); \ 314 } while (0) 315 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 316 317 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 318 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 319 const char dev_name[] = "fortify-test"; \ 320 struct device *dev; \ 321 void *orig; \ 322 size_t len; \ 323 \ 324 /* Create dummy device for devm_kmalloc()-family tests. */ \ 325 dev = kunit_device_register(test, dev_name); \ 326 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 327 "Cannot register test device\n"); \ 328 \ 329 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 330 devm_kfree(dev, p)); \ 331 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 332 devm_kfree(dev, p)); \ 333 checker(expected_size, \ 334 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 335 devm_kfree(dev, p)); \ 336 checker(expected_size, \ 337 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 338 devm_kfree(dev, p)); \ 339 checker(expected_size, \ 340 devm_kcalloc(dev, 1, alloc_size, gfp), \ 341 devm_kfree(dev, p)); \ 342 checker(expected_size, \ 343 devm_kcalloc(dev, alloc_size, 1, gfp), \ 344 devm_kfree(dev, p)); \ 345 \ 346 orig = devm_kmalloc(dev, alloc_size, gfp); \ 347 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 348 checker((expected_size) * 2, \ 349 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 350 devm_kfree(dev, p)); \ 351 \ 352 len = 4; \ 353 /* Using memdup() with fixed size, so force unknown length. */ \ 354 if (!__builtin_constant_p(expected_size)) \ 355 len += zero_size; \ 356 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 357 devm_kfree(dev, p)); \ 358 \ 359 kunit_device_unregister(test, dev); \ 360 } while (0) 361 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 362 363 static const char * const test_strs[] = { 364 "", 365 "Hello there", 366 "A longer string, just for variety", 367 }; 368 369 #define TEST_realloc(checker) do { \ 370 gfp_t gfp = GFP_KERNEL; \ 371 size_t len; \ 372 int i; \ 373 \ 374 for (i = 0; i < ARRAY_SIZE(test_strs); i++) { \ 375 len = strlen(test_strs[i]); \ 376 KUNIT_EXPECT_EQ(test, __builtin_constant_p(len), 0); \ 377 checker(len, kmemdup_array(test_strs[i], len, 1, gfp), \ 378 kfree(p)); \ 379 checker(len, kmemdup(test_strs[i], len, gfp), \ 380 kfree(p)); \ 381 } \ 382 } while (0) 383 static void fortify_test_realloc_size(struct kunit *test) 384 { 385 TEST_realloc(check_dynamic); 386 } 387 388 /* 389 * We can't have an array at the end of a structure or else 390 * builds without -fstrict-flex-arrays=3 will report them as 391 * being an unknown length. Additionally, add bytes before 392 * and after the string to catch over/underflows if tests 393 * fail. 394 */ 395 struct fortify_padding { 396 unsigned long bytes_before; 397 char buf[32]; 398 unsigned long bytes_after; 399 }; 400 /* Force compiler into not being able to resolve size at compile-time. */ 401 static volatile int unconst; 402 403 static void fortify_test_strlen(struct kunit *test) 404 { 405 struct fortify_padding pad = { }; 406 int i, end = sizeof(pad.buf) - 1; 407 408 /* Fill 31 bytes with valid characters. */ 409 for (i = 0; i < sizeof(pad.buf) - 1; i++) 410 pad.buf[i] = i + '0'; 411 /* Trailing bytes are still %NUL. */ 412 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 413 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 414 415 /* String is terminated, so strlen() is valid. */ 416 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 417 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 418 419 /* Make string unterminated, and recount. */ 420 pad.buf[end] = 'A'; 421 end = sizeof(pad.buf); 422 KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); 423 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 424 } 425 426 static void fortify_test_strnlen(struct kunit *test) 427 { 428 struct fortify_padding pad = { }; 429 int i, end = sizeof(pad.buf) - 1; 430 431 /* Fill 31 bytes with valid characters. */ 432 for (i = 0; i < sizeof(pad.buf) - 1; i++) 433 pad.buf[i] = i + '0'; 434 /* Trailing bytes are still %NUL. */ 435 KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); 436 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 437 438 /* String is terminated, so strnlen() is valid. */ 439 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf)), end); 440 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 441 /* A truncated strnlen() will be safe, too. */ 442 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf) / 2), 443 sizeof(pad.buf) / 2); 444 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 445 446 /* Make string unterminated, and recount. */ 447 pad.buf[end] = 'A'; 448 end = sizeof(pad.buf); 449 /* Reading beyond with strncpy() will fail. */ 450 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 1), end); 451 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 452 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 2), end); 453 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 454 455 /* Early-truncated is safe still, though. */ 456 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 457 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 458 459 end = sizeof(pad.buf) / 2; 460 KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); 461 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 462 } 463 464 static void fortify_test_strcpy(struct kunit *test) 465 { 466 struct fortify_padding pad = { }; 467 char src[sizeof(pad.buf) + 1] = { }; 468 int i; 469 470 /* Fill 31 bytes with valid characters. */ 471 for (i = 0; i < sizeof(src) - 2; i++) 472 src[i] = i + '0'; 473 474 /* Destination is %NUL-filled to start with. */ 475 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 476 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 477 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 478 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 479 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 480 481 /* Legitimate strcpy() 1 less than of max size. */ 482 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 483 == pad.buf); 484 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 485 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 486 /* Only last byte should be %NUL */ 487 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 488 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 489 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 490 491 src[sizeof(src) - 2] = 'A'; 492 /* But now we trip the overflow checking. */ 493 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 494 == pad.buf); 495 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 496 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 497 /* Trailing %NUL -- thanks to FORTIFY. */ 498 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 499 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 500 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 501 /* And we will not have gone beyond. */ 502 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 503 504 src[sizeof(src) - 1] = 'A'; 505 /* And for sure now, two bytes past. */ 506 KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) 507 == pad.buf); 508 /* 509 * Which trips both the strlen() on the unterminated src, 510 * and the resulting copy attempt. 511 */ 512 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 513 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 514 /* Trailing %NUL -- thanks to FORTIFY. */ 515 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 516 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 517 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 518 /* And we will not have gone beyond. */ 519 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 520 } 521 522 static void fortify_test_strncpy(struct kunit *test) 523 { 524 struct fortify_padding pad = { }; 525 char src[] = "Copy me fully into a small buffer and I will overflow!"; 526 527 /* Destination is %NUL-filled to start with. */ 528 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 529 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 530 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 531 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 532 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 533 534 /* Legitimate strncpy() 1 less than of max size. */ 535 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 536 sizeof(pad.buf) + unconst - 1) 537 == pad.buf); 538 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 539 /* Only last byte should be %NUL */ 540 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 541 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 542 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 543 544 /* Legitimate (though unterminated) max-size strncpy. */ 545 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 546 sizeof(pad.buf) + unconst) 547 == pad.buf); 548 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 549 /* No trailing %NUL -- thanks strncpy API. */ 550 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 551 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 552 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 553 /* But we will not have gone beyond. */ 554 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 555 556 /* Now verify that FORTIFY is working... */ 557 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 558 sizeof(pad.buf) + unconst + 1) 559 == pad.buf); 560 /* Should catch the overflow. */ 561 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 562 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 563 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 564 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 565 /* And we will not have gone beyond. */ 566 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 567 568 /* And further... */ 569 KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, 570 sizeof(pad.buf) + unconst + 2) 571 == pad.buf); 572 /* Should catch the overflow. */ 573 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 574 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 575 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 576 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 577 /* And we will not have gone beyond. */ 578 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 579 } 580 581 static void fortify_test_strscpy(struct kunit *test) 582 { 583 struct fortify_padding pad = { }; 584 char src[] = "Copy me fully into a small buffer and I will overflow!"; 585 586 /* Destination is %NUL-filled to start with. */ 587 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 588 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 589 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 590 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 591 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 592 593 /* Legitimate strscpy() 1 less than of max size. */ 594 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 595 sizeof(pad.buf) + unconst - 1), 596 -E2BIG); 597 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 598 /* Keeping space for %NUL, last two bytes should be %NUL */ 599 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 600 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 601 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 602 603 /* Legitimate max-size strscpy. */ 604 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 605 sizeof(pad.buf) + unconst), 606 -E2BIG); 607 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 608 /* A trailing %NUL will exist. */ 609 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 610 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 611 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 612 613 /* Now verify that FORTIFY is working... */ 614 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 615 sizeof(pad.buf) + unconst + 1), 616 -E2BIG); 617 /* Should catch the overflow. */ 618 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 619 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 620 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 621 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 622 /* And we will not have gone beyond. */ 623 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 624 625 /* And much further... */ 626 KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, 627 sizeof(src) * 2 + unconst), 628 -E2BIG); 629 /* Should catch the overflow. */ 630 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 631 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 632 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 633 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 634 /* And we will not have gone beyond. */ 635 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 636 } 637 638 static void fortify_test_strcat(struct kunit *test) 639 { 640 struct fortify_padding pad = { }; 641 char src[sizeof(pad.buf) / 2] = { }; 642 char one[] = "A"; 643 char two[] = "BC"; 644 int i; 645 646 /* Fill 15 bytes with valid characters. */ 647 for (i = 0; i < sizeof(src) - 1; i++) 648 src[i] = i + 'A'; 649 650 /* Destination is %NUL-filled to start with. */ 651 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 652 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 653 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 654 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 655 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 656 657 /* Legitimate strcat() using less than half max size. */ 658 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 659 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 660 /* Legitimate strcat() now 2 bytes shy of end. */ 661 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); 662 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 663 /* Last two bytes should be %NUL */ 664 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 665 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 666 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 667 668 /* Add one more character to the end. */ 669 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 670 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 671 /* Last byte should be %NUL */ 672 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 673 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 674 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 675 676 /* And this one char will overflow. */ 677 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); 678 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 679 /* Last byte should be %NUL thanks to FORTIFY. */ 680 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 681 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 682 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 683 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 684 685 /* And adding two will overflow more. */ 686 KUNIT_ASSERT_TRUE(test, strcat(pad.buf, two) == pad.buf); 687 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 688 /* Last byte should be %NUL thanks to FORTIFY. */ 689 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 690 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 691 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 692 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 693 } 694 695 static void fortify_test_strncat(struct kunit *test) 696 { 697 struct fortify_padding pad = { }; 698 char src[sizeof(pad.buf)] = { }; 699 int i, partial; 700 701 /* Fill 31 bytes with valid characters. */ 702 partial = sizeof(src) / 2 - 1; 703 for (i = 0; i < partial; i++) 704 src[i] = i + 'A'; 705 706 /* Destination is %NUL-filled to start with. */ 707 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 708 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 709 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 710 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 711 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 712 713 /* Legitimate strncat() using less than half max size. */ 714 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 715 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 716 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 717 /* Legitimate strncat() now 2 bytes shy of end. */ 718 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); 719 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 720 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 721 /* Last two bytes should be %NUL */ 722 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 723 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 724 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 725 726 /* Add one more character to the end. */ 727 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 728 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 729 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 730 /* Last byte should be %NUL */ 731 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 732 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 733 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 734 735 /* And this one char will overflow. */ 736 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 737 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 738 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 739 /* Last byte should be %NUL thanks to FORTIFY. */ 740 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 741 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 742 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 743 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 744 745 /* And adding two will overflow more. */ 746 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 2) == pad.buf); 747 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 748 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 749 /* Last byte should be %NUL thanks to FORTIFY. */ 750 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 751 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 752 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 753 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 754 755 /* Force an unterminated destination, and overflow. */ 756 pad.buf[sizeof(pad.buf) - 1] = 'A'; 757 KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); 758 /* This will have tripped both strlen() and strcat(). */ 759 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 760 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 761 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 762 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 763 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 764 /* But we should not go beyond the end. */ 765 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 766 } 767 768 static void fortify_test_strlcat(struct kunit *test) 769 { 770 struct fortify_padding pad = { }; 771 char src[sizeof(pad.buf)] = { }; 772 int i, partial; 773 int len = sizeof(pad.buf) + unconst; 774 775 /* Fill 15 bytes with valid characters. */ 776 partial = sizeof(src) / 2 - 1; 777 for (i = 0; i < partial; i++) 778 src[i] = i + 'A'; 779 780 /* Destination is %NUL-filled to start with. */ 781 KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); 782 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 783 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 784 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 785 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 786 787 /* Legitimate strlcat() using less than half max size. */ 788 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial); 789 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 790 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 791 /* Legitimate strlcat() now 2 bytes shy of end. */ 792 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial * 2); 793 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 794 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 795 /* Last two bytes should be %NUL */ 796 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 797 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 798 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 799 800 /* Add one more character to the end. */ 801 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "Q", len), partial * 2 + 1); 802 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 803 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); 804 /* Last byte should be %NUL */ 805 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 806 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 807 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 808 809 /* And this one char will overflow. */ 810 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "V", len * 2), len); 811 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 812 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); 813 /* Last byte should be %NUL thanks to FORTIFY. */ 814 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 815 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 816 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 817 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 818 819 /* And adding two will overflow more. */ 820 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "QQ", len * 2), len + 1); 821 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 822 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 823 /* Last byte should be %NUL thanks to FORTIFY. */ 824 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 825 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 826 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 827 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 828 829 /* Force an unterminated destination, and overflow. */ 830 pad.buf[sizeof(pad.buf) - 1] = 'A'; 831 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "TT", len * 2), len + 2); 832 /* This will have tripped both strlen() and strlcat(). */ 833 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 834 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); 835 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 836 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); 837 KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); 838 /* But we should not go beyond the end. */ 839 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 840 841 /* Force an unterminated source, and overflow. */ 842 memset(src, 'B', sizeof(src)); 843 pad.buf[sizeof(pad.buf) - 1] = '\0'; 844 KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len * 3), len - 1 + sizeof(src)); 845 /* This will have tripped both strlen() and strlcat(). */ 846 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 847 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); 848 KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); 849 /* But we should not go beyond the end. */ 850 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); 851 } 852 853 /* Check for 0-sized arrays... */ 854 struct fortify_zero_sized { 855 unsigned long bytes_before; 856 char buf[0]; 857 unsigned long bytes_after; 858 }; 859 860 #define __fortify_test(memfunc) \ 861 static void fortify_test_##memfunc(struct kunit *test) \ 862 { \ 863 struct fortify_zero_sized zero = { }; \ 864 struct fortify_padding pad = { }; \ 865 char srcA[sizeof(pad.buf) + 2]; \ 866 char srcB[sizeof(pad.buf) + 2]; \ 867 size_t len = sizeof(pad.buf) + unconst; \ 868 \ 869 memset(srcA, 'A', sizeof(srcA)); \ 870 KUNIT_ASSERT_EQ(test, srcA[0], 'A'); \ 871 memset(srcB, 'B', sizeof(srcB)); \ 872 KUNIT_ASSERT_EQ(test, srcB[0], 'B'); \ 873 \ 874 memfunc(pad.buf, srcA, 0 + unconst); \ 875 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 876 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 877 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 878 memfunc(pad.buf + 1, srcB, 1 + unconst); \ 879 KUNIT_EXPECT_EQ(test, pad.buf[0], '\0'); \ 880 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 881 KUNIT_EXPECT_EQ(test, pad.buf[2], '\0'); \ 882 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 883 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 884 memfunc(pad.buf, srcA, 1 + unconst); \ 885 KUNIT_EXPECT_EQ(test, pad.buf[0], 'A'); \ 886 KUNIT_EXPECT_EQ(test, pad.buf[1], 'B'); \ 887 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 888 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 889 memfunc(pad.buf, srcA, len - 1); \ 890 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 891 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], '\0'); \ 892 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 893 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 894 memfunc(pad.buf, srcA, len); \ 895 KUNIT_EXPECT_EQ(test, pad.buf[1], 'A'); \ 896 KUNIT_EXPECT_EQ(test, pad.buf[len - 1], 'A'); \ 897 KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); \ 898 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 899 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 900 memfunc(pad.buf, srcA, len + 1); \ 901 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 902 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); \ 903 memfunc(pad.buf + 1, srcB, len); \ 904 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 905 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); \ 906 \ 907 /* Reset error counter. */ \ 908 fortify_write_overflows = 0; \ 909 /* Copy nothing into nothing: no errors. */ \ 910 memfunc(zero.buf, srcB, 0 + unconst); \ 911 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 912 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 913 /* We currently explicitly ignore zero-sized dests. */ \ 914 memfunc(zero.buf, srcB, 1 + unconst); \ 915 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); \ 916 KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); \ 917 } 918 __fortify_test(memcpy) 919 __fortify_test(memmove) 920 921 static void fortify_test_memscan(struct kunit *test) 922 { 923 char haystack[] = "Where oh where is my memory range?"; 924 char *mem = haystack + strlen("Where oh where is "); 925 char needle = 'm'; 926 size_t len = sizeof(haystack) + unconst; 927 928 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len), 929 mem); 930 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 931 /* Catch too-large range. */ 932 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len + 1), 933 NULL); 934 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 935 KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len * 2), 936 NULL); 937 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 938 } 939 940 static void fortify_test_memchr(struct kunit *test) 941 { 942 char haystack[] = "Where oh where is my memory range?"; 943 char *mem = haystack + strlen("Where oh where is "); 944 char needle = 'm'; 945 size_t len = sizeof(haystack) + unconst; 946 947 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len), 948 mem); 949 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 950 /* Catch too-large range. */ 951 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len + 1), 952 NULL); 953 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 954 KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len * 2), 955 NULL); 956 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 957 } 958 959 static void fortify_test_memchr_inv(struct kunit *test) 960 { 961 char haystack[] = "Where oh where is my memory range?"; 962 char *mem = haystack + 1; 963 char needle = 'W'; 964 size_t len = sizeof(haystack) + unconst; 965 966 /* Normal search is okay. */ 967 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len), 968 mem); 969 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 970 /* Catch too-large range. */ 971 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len + 1), 972 NULL); 973 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 974 KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len * 2), 975 NULL); 976 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 977 } 978 979 static void fortify_test_memcmp(struct kunit *test) 980 { 981 char one[] = "My mind is going ..."; 982 char two[] = "My mind is going ... I can feel it."; 983 size_t one_len = sizeof(one) + unconst - 1; 984 size_t two_len = sizeof(two) + unconst - 1; 985 986 /* We match the first string (ignoring the %NUL). */ 987 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len), 0); 988 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 989 /* Still in bounds, but no longer matching. */ 990 KUNIT_ASSERT_LT(test, memcmp(one, two, one_len + 1), 0); 991 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 992 993 /* Catch too-large ranges. */ 994 KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 2), INT_MIN); 995 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 996 997 KUNIT_ASSERT_EQ(test, memcmp(two, one, two_len + 2), INT_MIN); 998 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 999 } 1000 1001 static void fortify_test_kmemdup(struct kunit *test) 1002 { 1003 char src[] = "I got Doom running on it!"; 1004 char *copy; 1005 size_t len = sizeof(src) + unconst; 1006 1007 /* Copy is within bounds. */ 1008 copy = kmemdup(src, len, GFP_KERNEL); 1009 KUNIT_EXPECT_NOT_NULL(test, copy); 1010 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1011 kfree(copy); 1012 1013 /* Without %NUL. */ 1014 copy = kmemdup(src, len - 1, GFP_KERNEL); 1015 KUNIT_EXPECT_NOT_NULL(test, copy); 1016 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1017 kfree(copy); 1018 1019 /* Tiny bounds. */ 1020 copy = kmemdup(src, 1, GFP_KERNEL); 1021 KUNIT_EXPECT_NOT_NULL(test, copy); 1022 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); 1023 kfree(copy); 1024 1025 /* Out of bounds by 1 byte. */ 1026 copy = kmemdup(src, len + 1, GFP_KERNEL); 1027 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1028 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); 1029 kfree(copy); 1030 1031 /* Way out of bounds. */ 1032 copy = kmemdup(src, len * 2, GFP_KERNEL); 1033 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1034 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); 1035 kfree(copy); 1036 1037 /* Starting offset causing out of bounds. */ 1038 copy = kmemdup(src + 1, len, GFP_KERNEL); 1039 KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR); 1040 KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); 1041 kfree(copy); 1042 } 1043 1044 static int fortify_test_init(struct kunit *test) 1045 { 1046 if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) 1047 kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); 1048 1049 fortify_read_overflows = 0; 1050 kunit_add_named_resource(test, NULL, NULL, &read_resource, 1051 "fortify_read_overflows", 1052 &fortify_read_overflows); 1053 fortify_write_overflows = 0; 1054 kunit_add_named_resource(test, NULL, NULL, &write_resource, 1055 "fortify_write_overflows", 1056 &fortify_write_overflows); 1057 return 0; 1058 } 1059 1060 static struct kunit_case fortify_test_cases[] = { 1061 KUNIT_CASE(fortify_test_known_sizes), 1062 KUNIT_CASE(fortify_test_control_flow_split), 1063 KUNIT_CASE(fortify_test_alloc_size_kmalloc_const), 1064 KUNIT_CASE(fortify_test_alloc_size_kmalloc_dynamic), 1065 KUNIT_CASE(fortify_test_alloc_size_vmalloc_const), 1066 KUNIT_CASE(fortify_test_alloc_size_vmalloc_dynamic), 1067 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_const), 1068 KUNIT_CASE(fortify_test_alloc_size_kvmalloc_dynamic), 1069 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_const), 1070 KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_dynamic), 1071 KUNIT_CASE(fortify_test_realloc_size), 1072 KUNIT_CASE(fortify_test_strlen), 1073 KUNIT_CASE(fortify_test_strnlen), 1074 KUNIT_CASE(fortify_test_strcpy), 1075 KUNIT_CASE(fortify_test_strncpy), 1076 KUNIT_CASE(fortify_test_strscpy), 1077 KUNIT_CASE(fortify_test_strcat), 1078 KUNIT_CASE(fortify_test_strncat), 1079 KUNIT_CASE(fortify_test_strlcat), 1080 /* skip memset: performs bounds checking on whole structs */ 1081 KUNIT_CASE(fortify_test_memcpy), 1082 KUNIT_CASE(fortify_test_memmove), 1083 KUNIT_CASE(fortify_test_memscan), 1084 KUNIT_CASE(fortify_test_memchr), 1085 KUNIT_CASE(fortify_test_memchr_inv), 1086 KUNIT_CASE(fortify_test_memcmp), 1087 KUNIT_CASE(fortify_test_kmemdup), 1088 {} 1089 }; 1090 1091 static struct kunit_suite fortify_test_suite = { 1092 .name = "fortify", 1093 .init = fortify_test_init, 1094 .test_cases = fortify_test_cases, 1095 }; 1096 1097 kunit_test_suite(fortify_test_suite); 1098 1099 MODULE_LICENSE("GPL"); 1100