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 /* Handle being built without CONFIG_FORTIFY_SOURCE */ 29 #ifndef __compiletime_strlen 30 # define __compiletime_strlen __builtin_strlen 31 #endif 32 33 static void known_sizes_test(struct kunit *test) 34 { 35 KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); 36 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); 37 KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); 38 39 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); 40 /* Externally defined and dynamically sized string pointer: */ 41 KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); 42 } 43 44 /* This is volatile so the optimizer can't perform DCE below. */ 45 static volatile int pick; 46 47 /* Not inline to keep optimizer from figuring out which string we want. */ 48 static noinline size_t want_minus_one(int pick) 49 { 50 const char *str; 51 52 switch (pick) { 53 case 1: 54 str = "4444"; 55 break; 56 case 2: 57 str = "333"; 58 break; 59 default: 60 str = "1"; 61 break; 62 } 63 return __compiletime_strlen(str); 64 } 65 66 static void control_flow_split_test(struct kunit *test) 67 { 68 KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); 69 } 70 71 #define KUNIT_EXPECT_BOS(test, p, expected, name) \ 72 KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ 73 expected, \ 74 "__alloc_size() not working with __bos on " name "\n") 75 76 #if !__has_builtin(__builtin_dynamic_object_size) 77 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 78 /* Silence "unused variable 'expected'" warning. */ \ 79 KUNIT_EXPECT_EQ(test, expected, expected) 80 #else 81 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 82 KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ 83 expected, \ 84 "__alloc_size() not working with __bdos on " name "\n") 85 #endif 86 87 /* If the execpted size is a constant value, __bos can see it. */ 88 #define check_const(_expected, alloc, free) do { \ 89 size_t expected = (_expected); \ 90 void *p = alloc; \ 91 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 92 KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ 93 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 94 free; \ 95 } while (0) 96 97 /* If the execpted size is NOT a constant value, __bos CANNOT see it. */ 98 #define check_dynamic(_expected, alloc, free) do { \ 99 size_t expected = (_expected); \ 100 void *p = alloc; \ 101 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 102 KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ 103 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 104 free; \ 105 } while (0) 106 107 /* Assortment of constant-value kinda-edge cases. */ 108 #define CONST_TEST_BODY(TEST_alloc) do { \ 109 /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ 110 if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ 111 TEST_alloc(check_const, 0, 0); \ 112 TEST_alloc(check_const, 1, 1); \ 113 TEST_alloc(check_const, 128, 128); \ 114 TEST_alloc(check_const, 1023, 1023); \ 115 TEST_alloc(check_const, 1025, 1025); \ 116 TEST_alloc(check_const, 4096, 4096); \ 117 TEST_alloc(check_const, 4097, 4097); \ 118 } while (0) 119 120 static volatile size_t zero_size; 121 static volatile size_t unknown_size = 50; 122 123 #if !__has_builtin(__builtin_dynamic_object_size) 124 #define DYNAMIC_TEST_BODY(TEST_alloc) \ 125 kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") 126 #else 127 #define DYNAMIC_TEST_BODY(TEST_alloc) do { \ 128 size_t size = unknown_size; \ 129 \ 130 /* \ 131 * Expected size is "size" in each test, before it is then \ 132 * internally incremented in each test. Requires we disable \ 133 * -Wunsequenced. \ 134 */ \ 135 TEST_alloc(check_dynamic, size, size++); \ 136 /* Make sure incrementing actually happened. */ \ 137 KUNIT_EXPECT_NE(test, size, unknown_size); \ 138 } while (0) 139 #endif 140 141 #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ 142 static void alloc_size_##allocator##_const_test(struct kunit *test) \ 143 { \ 144 CONST_TEST_BODY(TEST_##allocator); \ 145 } \ 146 static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \ 147 { \ 148 DYNAMIC_TEST_BODY(TEST_##allocator); \ 149 } 150 151 #define TEST_kmalloc(checker, expected_size, alloc_size) do { \ 152 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 153 void *orig; \ 154 size_t len; \ 155 \ 156 checker(expected_size, kmalloc(alloc_size, gfp), \ 157 kfree(p)); \ 158 checker(expected_size, \ 159 kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 160 kfree(p)); \ 161 checker(expected_size, kzalloc(alloc_size, gfp), \ 162 kfree(p)); \ 163 checker(expected_size, \ 164 kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 165 kfree(p)); \ 166 checker(expected_size, kcalloc(1, alloc_size, gfp), \ 167 kfree(p)); \ 168 checker(expected_size, kcalloc(alloc_size, 1, gfp), \ 169 kfree(p)); \ 170 checker(expected_size, \ 171 kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 172 kfree(p)); \ 173 checker(expected_size, \ 174 kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 175 kfree(p)); \ 176 checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ 177 kfree(p)); \ 178 checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ 179 kfree(p)); \ 180 checker(expected_size, \ 181 kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 182 kfree(p)); \ 183 checker(expected_size, \ 184 kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 185 kfree(p)); \ 186 checker(expected_size, __kmalloc(alloc_size, gfp), \ 187 kfree(p)); \ 188 checker(expected_size, \ 189 __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 190 kfree(p)); \ 191 \ 192 orig = kmalloc(alloc_size, gfp); \ 193 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 194 checker((expected_size) * 2, \ 195 krealloc(orig, (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, 1, (alloc_size) * 2, gfp), \ 201 kfree(p)); \ 202 orig = kmalloc(alloc_size, gfp); \ 203 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 204 checker((expected_size) * 2, \ 205 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ 206 kfree(p)); \ 207 \ 208 len = 11; \ 209 /* Using memdup() with fixed size, so force unknown length. */ \ 210 if (!__builtin_constant_p(expected_size)) \ 211 len += zero_size; \ 212 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ 213 } while (0) 214 DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) 215 216 /* Sizes are in pages, not bytes. */ 217 #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ 218 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 219 checker((expected_pages) * PAGE_SIZE, \ 220 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 221 checker((expected_pages) * PAGE_SIZE, \ 222 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 223 checker((expected_pages) * PAGE_SIZE, \ 224 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ 225 } while (0) 226 DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) 227 228 /* Sizes are in pages (and open-coded for side-effects), not bytes. */ 229 #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ 230 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 231 size_t prev_size; \ 232 void *orig; \ 233 \ 234 checker((expected_pages) * PAGE_SIZE, \ 235 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ 236 vfree(p)); \ 237 checker((expected_pages) * PAGE_SIZE, \ 238 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 239 vfree(p)); \ 240 checker((expected_pages) * PAGE_SIZE, \ 241 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ 242 vfree(p)); \ 243 checker((expected_pages) * PAGE_SIZE, \ 244 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 245 vfree(p)); \ 246 checker((expected_pages) * PAGE_SIZE, \ 247 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ 248 vfree(p)); \ 249 checker((expected_pages) * PAGE_SIZE, \ 250 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ 251 vfree(p)); \ 252 checker((expected_pages) * PAGE_SIZE, \ 253 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ 254 vfree(p)); \ 255 checker((expected_pages) * PAGE_SIZE, \ 256 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ 257 vfree(p)); \ 258 \ 259 prev_size = (expected_pages) * PAGE_SIZE; \ 260 orig = kvmalloc(prev_size, gfp); \ 261 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 262 checker(((expected_pages) * PAGE_SIZE) * 2, \ 263 kvrealloc(orig, prev_size, \ 264 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 265 kvfree(p)); \ 266 } while (0) 267 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 268 269 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 270 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 271 const char dev_name[] = "fortify-test"; \ 272 struct device *dev; \ 273 void *orig; \ 274 size_t len; \ 275 \ 276 /* Create dummy device for devm_kmalloc()-family tests. */ \ 277 dev = root_device_register(dev_name); \ 278 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 279 "Cannot register test device\n"); \ 280 \ 281 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 282 devm_kfree(dev, p)); \ 283 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 284 devm_kfree(dev, p)); \ 285 checker(expected_size, \ 286 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 287 devm_kfree(dev, p)); \ 288 checker(expected_size, \ 289 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 290 devm_kfree(dev, p)); \ 291 checker(expected_size, \ 292 devm_kcalloc(dev, 1, alloc_size, gfp), \ 293 devm_kfree(dev, p)); \ 294 checker(expected_size, \ 295 devm_kcalloc(dev, alloc_size, 1, gfp), \ 296 devm_kfree(dev, p)); \ 297 \ 298 orig = devm_kmalloc(dev, alloc_size, gfp); \ 299 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 300 checker((expected_size) * 2, \ 301 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 302 devm_kfree(dev, p)); \ 303 \ 304 len = 4; \ 305 /* Using memdup() with fixed size, so force unknown length. */ \ 306 if (!__builtin_constant_p(expected_size)) \ 307 len += zero_size; \ 308 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 309 devm_kfree(dev, p)); \ 310 \ 311 device_unregister(dev); \ 312 } while (0) 313 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 314 315 static int fortify_test_init(struct kunit *test) 316 { 317 if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) 318 kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); 319 320 return 0; 321 } 322 323 static struct kunit_case fortify_test_cases[] = { 324 KUNIT_CASE(known_sizes_test), 325 KUNIT_CASE(control_flow_split_test), 326 KUNIT_CASE(alloc_size_kmalloc_const_test), 327 KUNIT_CASE(alloc_size_kmalloc_dynamic_test), 328 KUNIT_CASE(alloc_size_vmalloc_const_test), 329 KUNIT_CASE(alloc_size_vmalloc_dynamic_test), 330 KUNIT_CASE(alloc_size_kvmalloc_const_test), 331 KUNIT_CASE(alloc_size_kvmalloc_dynamic_test), 332 KUNIT_CASE(alloc_size_devm_kmalloc_const_test), 333 KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test), 334 {} 335 }; 336 337 static struct kunit_suite fortify_test_suite = { 338 .name = "fortify", 339 .init = fortify_test_init, 340 .test_cases = fortify_test_cases, 341 }; 342 343 kunit_test_suite(fortify_test_suite); 344 345 MODULE_LICENSE("GPL"); 346