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/device.h> 19 #include <kunit/test.h> 20 #include <linux/device.h> 21 #include <linux/slab.h> 22 #include <linux/string.h> 23 #include <linux/vmalloc.h> 24 25 static const char array_of_10[] = "this is 10"; 26 static const char *ptr_of_11 = "this is 11!"; 27 static char array_unknown[] = "compiler thinks I might change"; 28 29 static void known_sizes_test(struct kunit *test) 30 { 31 KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); 32 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); 33 KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); 34 35 KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); 36 /* Externally defined and dynamically sized string pointer: */ 37 KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); 38 } 39 40 /* This is volatile so the optimizer can't perform DCE below. */ 41 static volatile int pick; 42 43 /* Not inline to keep optimizer from figuring out which string we want. */ 44 static noinline size_t want_minus_one(int pick) 45 { 46 const char *str; 47 48 switch (pick) { 49 case 1: 50 str = "4444"; 51 break; 52 case 2: 53 str = "333"; 54 break; 55 default: 56 str = "1"; 57 break; 58 } 59 return __compiletime_strlen(str); 60 } 61 62 static void control_flow_split_test(struct kunit *test) 63 { 64 KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); 65 } 66 67 #define KUNIT_EXPECT_BOS(test, p, expected, name) \ 68 KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ 69 expected, \ 70 "__alloc_size() not working with __bos on " name "\n") 71 72 #if !__has_builtin(__builtin_dynamic_object_size) 73 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 74 /* Silence "unused variable 'expected'" warning. */ \ 75 KUNIT_EXPECT_EQ(test, expected, expected) 76 #else 77 #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ 78 KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ 79 expected, \ 80 "__alloc_size() not working with __bdos on " name "\n") 81 #endif 82 83 /* If the execpted size is a constant value, __bos can see it. */ 84 #define check_const(_expected, alloc, free) do { \ 85 size_t expected = (_expected); \ 86 void *p = alloc; \ 87 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 88 KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ 89 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 90 free; \ 91 } while (0) 92 93 /* If the execpted size is NOT a constant value, __bos CANNOT see it. */ 94 #define check_dynamic(_expected, alloc, free) do { \ 95 size_t expected = (_expected); \ 96 void *p = alloc; \ 97 KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ 98 KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ 99 KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ 100 free; \ 101 } while (0) 102 103 /* Assortment of constant-value kinda-edge cases. */ 104 #define CONST_TEST_BODY(TEST_alloc) do { \ 105 /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ 106 if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ 107 TEST_alloc(check_const, 0, 0); \ 108 TEST_alloc(check_const, 1, 1); \ 109 TEST_alloc(check_const, 128, 128); \ 110 TEST_alloc(check_const, 1023, 1023); \ 111 TEST_alloc(check_const, 1025, 1025); \ 112 TEST_alloc(check_const, 4096, 4096); \ 113 TEST_alloc(check_const, 4097, 4097); \ 114 } while (0) 115 116 static volatile size_t zero_size; 117 static volatile size_t unknown_size = 50; 118 119 #if !__has_builtin(__builtin_dynamic_object_size) 120 #define DYNAMIC_TEST_BODY(TEST_alloc) \ 121 kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") 122 #else 123 #define DYNAMIC_TEST_BODY(TEST_alloc) do { \ 124 size_t size = unknown_size; \ 125 \ 126 /* \ 127 * Expected size is "size" in each test, before it is then \ 128 * internally incremented in each test. Requires we disable \ 129 * -Wunsequenced. \ 130 */ \ 131 TEST_alloc(check_dynamic, size, size++); \ 132 /* Make sure incrementing actually happened. */ \ 133 KUNIT_EXPECT_NE(test, size, unknown_size); \ 134 } while (0) 135 #endif 136 137 #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ 138 static void alloc_size_##allocator##_const_test(struct kunit *test) \ 139 { \ 140 CONST_TEST_BODY(TEST_##allocator); \ 141 } \ 142 static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \ 143 { \ 144 DYNAMIC_TEST_BODY(TEST_##allocator); \ 145 } 146 147 #define TEST_kmalloc(checker, expected_size, alloc_size) do { \ 148 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 149 void *orig; \ 150 size_t len; \ 151 \ 152 checker(expected_size, kmalloc(alloc_size, gfp), \ 153 kfree(p)); \ 154 checker(expected_size, \ 155 kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 156 kfree(p)); \ 157 checker(expected_size, kzalloc(alloc_size, gfp), \ 158 kfree(p)); \ 159 checker(expected_size, \ 160 kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 161 kfree(p)); \ 162 checker(expected_size, kcalloc(1, alloc_size, gfp), \ 163 kfree(p)); \ 164 checker(expected_size, kcalloc(alloc_size, 1, gfp), \ 165 kfree(p)); \ 166 checker(expected_size, \ 167 kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 168 kfree(p)); \ 169 checker(expected_size, \ 170 kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 171 kfree(p)); \ 172 checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ 173 kfree(p)); \ 174 checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ 175 kfree(p)); \ 176 checker(expected_size, \ 177 kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ 178 kfree(p)); \ 179 checker(expected_size, \ 180 kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ 181 kfree(p)); \ 182 checker(expected_size, __kmalloc(alloc_size, gfp), \ 183 kfree(p)); \ 184 checker(expected_size, \ 185 __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ 186 kfree(p)); \ 187 \ 188 orig = kmalloc(alloc_size, gfp); \ 189 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 190 checker((expected_size) * 2, \ 191 krealloc(orig, (alloc_size) * 2, gfp), \ 192 kfree(p)); \ 193 orig = kmalloc(alloc_size, gfp); \ 194 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 195 checker((expected_size) * 2, \ 196 krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ 197 kfree(p)); \ 198 orig = kmalloc(alloc_size, gfp); \ 199 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 200 checker((expected_size) * 2, \ 201 krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ 202 kfree(p)); \ 203 \ 204 len = 11; \ 205 /* Using memdup() with fixed size, so force unknown length. */ \ 206 if (!__builtin_constant_p(expected_size)) \ 207 len += zero_size; \ 208 checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ 209 } while (0) 210 DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) 211 212 /* Sizes are in pages, not bytes. */ 213 #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ 214 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 215 checker((expected_pages) * PAGE_SIZE, \ 216 vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 217 checker((expected_pages) * PAGE_SIZE, \ 218 vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ 219 checker((expected_pages) * PAGE_SIZE, \ 220 __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ 221 } while (0) 222 DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) 223 224 /* Sizes are in pages (and open-coded for side-effects), not bytes. */ 225 #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ 226 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 227 size_t prev_size; \ 228 void *orig; \ 229 \ 230 checker((expected_pages) * PAGE_SIZE, \ 231 kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ 232 vfree(p)); \ 233 checker((expected_pages) * PAGE_SIZE, \ 234 kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 235 vfree(p)); \ 236 checker((expected_pages) * PAGE_SIZE, \ 237 kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ 238 vfree(p)); \ 239 checker((expected_pages) * PAGE_SIZE, \ 240 kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ 241 vfree(p)); \ 242 checker((expected_pages) * PAGE_SIZE, \ 243 kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ 244 vfree(p)); \ 245 checker((expected_pages) * PAGE_SIZE, \ 246 kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ 247 vfree(p)); \ 248 checker((expected_pages) * PAGE_SIZE, \ 249 kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ 250 vfree(p)); \ 251 checker((expected_pages) * PAGE_SIZE, \ 252 kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ 253 vfree(p)); \ 254 \ 255 prev_size = (expected_pages) * PAGE_SIZE; \ 256 orig = kvmalloc(prev_size, gfp); \ 257 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 258 checker(((expected_pages) * PAGE_SIZE) * 2, \ 259 kvrealloc(orig, prev_size, \ 260 ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ 261 kvfree(p)); \ 262 } while (0) 263 DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) 264 265 #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ 266 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ 267 const char dev_name[] = "fortify-test"; \ 268 struct device *dev; \ 269 void *orig; \ 270 size_t len; \ 271 \ 272 /* Create dummy device for devm_kmalloc()-family tests. */ \ 273 dev = kunit_device_register(test, dev_name); \ 274 KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ 275 "Cannot register test device\n"); \ 276 \ 277 checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ 278 devm_kfree(dev, p)); \ 279 checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ 280 devm_kfree(dev, p)); \ 281 checker(expected_size, \ 282 devm_kmalloc_array(dev, 1, alloc_size, gfp), \ 283 devm_kfree(dev, p)); \ 284 checker(expected_size, \ 285 devm_kmalloc_array(dev, alloc_size, 1, gfp), \ 286 devm_kfree(dev, p)); \ 287 checker(expected_size, \ 288 devm_kcalloc(dev, 1, alloc_size, gfp), \ 289 devm_kfree(dev, p)); \ 290 checker(expected_size, \ 291 devm_kcalloc(dev, alloc_size, 1, gfp), \ 292 devm_kfree(dev, p)); \ 293 \ 294 orig = devm_kmalloc(dev, alloc_size, gfp); \ 295 KUNIT_EXPECT_TRUE(test, orig != NULL); \ 296 checker((expected_size) * 2, \ 297 devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ 298 devm_kfree(dev, p)); \ 299 \ 300 len = 4; \ 301 /* Using memdup() with fixed size, so force unknown length. */ \ 302 if (!__builtin_constant_p(expected_size)) \ 303 len += zero_size; \ 304 checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ 305 devm_kfree(dev, p)); \ 306 \ 307 kunit_device_unregister(test, dev); \ 308 } while (0) 309 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) 310 311 static struct kunit_case fortify_test_cases[] = { 312 KUNIT_CASE(known_sizes_test), 313 KUNIT_CASE(control_flow_split_test), 314 KUNIT_CASE(alloc_size_kmalloc_const_test), 315 KUNIT_CASE(alloc_size_kmalloc_dynamic_test), 316 KUNIT_CASE(alloc_size_vmalloc_const_test), 317 KUNIT_CASE(alloc_size_vmalloc_dynamic_test), 318 KUNIT_CASE(alloc_size_kvmalloc_const_test), 319 KUNIT_CASE(alloc_size_kvmalloc_dynamic_test), 320 KUNIT_CASE(alloc_size_devm_kmalloc_const_test), 321 KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test), 322 {} 323 }; 324 325 static struct kunit_suite fortify_test_suite = { 326 .name = "fortify", 327 .test_cases = fortify_test_cases, 328 }; 329 330 kunit_test_suite(fortify_test_suite); 331 332 MODULE_LICENSE("GPL"); 333