| 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"); |