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