| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Kees Cook | 5806 | 99.91% | 8 | 88.89% |
| David Gow | 5 | 0.09% | 1 | 11.11% |
| Total | 5811 | 9 |
// SPDX-License-Identifier: GPL-2.0 /* * Runtime test cases for CONFIG_FORTIFY_SOURCE. For testing memcpy(), * see FORTIFY_MEM_* tests in LKDTM (drivers/misc/lkdtm/fortify.c). * * For corner cases with UBSAN, try testing with: * * ./tools/testing/kunit/kunit.py run --arch=x86_64 \ * --kconfig_add CONFIG_FORTIFY_SOURCE=y \ * --kconfig_add CONFIG_UBSAN=y \ * --kconfig_add CONFIG_UBSAN_TRAP=y \ * --kconfig_add CONFIG_UBSAN_BOUNDS=y \ * --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \ * --make_options LLVM=1 fortify */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt /* Redefine fortify_panic() to track failures. */ void fortify_add_kunit_error(int write); #define fortify_panic(func, write, avail, size, retfail) do { \ __fortify_report(FORTIFY_REASON(func, write), avail, size); \ fortify_add_kunit_error(write); \ return (retfail); \ } while (0) #include <kunit/device.h> #include <kunit/test.h> #include <kunit/test-bug.h> #include <linux/device.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/vmalloc.h> /* Handle being built without CONFIG_FORTIFY_SOURCE */ #ifndef __compiletime_strlen # define __compiletime_strlen __builtin_strlen #endif static struct kunit_resource read_resource; static struct kunit_resource write_resource; static int fortify_read_overflows; static int fortify_write_overflows; static const char array_of_10[] = "this is 10"; static const char *ptr_of_11 = "this is 11!"; static char array_unknown[] = "compiler thinks I might change"; void fortify_add_kunit_error(int write) { struct kunit_resource *resource; struct kunit *current_test; current_test = kunit_get_current_test(); if (!current_test) return; resource = kunit_find_named_resource(current_test, write ? "fortify_write_overflows" : "fortify_read_overflows"); if (!resource) return; (*(int *)resource->data)++; kunit_put_resource(resource); } static void known_sizes_test(struct kunit *test) { KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8); KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); /* Externally defined and dynamically sized string pointer: */ KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); } /* This is volatile so the optimizer can't perform DCE below. */ static volatile int pick; /* Not inline to keep optimizer from figuring out which string we want. */ static noinline size_t want_minus_one(int pick) { const char *str; switch (pick) { case 1: str = "4444"; break; case 2: str = "333"; break; default: str = "1"; break; } return __compiletime_strlen(str); } static void control_flow_split_test(struct kunit *test) { KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); } #define KUNIT_EXPECT_BOS(test, p, expected, name) \ KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ expected, \ "__alloc_size() not working with __bos on " name "\n") #if !__has_builtin(__builtin_dynamic_object_size) #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ /* Silence "unused variable 'expected'" warning. */ \ KUNIT_EXPECT_EQ(test, expected, expected) #else #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ expected, \ "__alloc_size() not working with __bdos on " name "\n") #endif /* If the execpted size is a constant value, __bos can see it. */ #define check_const(_expected, alloc, free) do { \ size_t expected = (_expected); \ void *p = alloc; \ KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ KUNIT_EXPECT_BOS(test, p, expected, #alloc); \ KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ free; \ } while (0) /* If the execpted size is NOT a constant value, __bos CANNOT see it. */ #define check_dynamic(_expected, alloc, free) do { \ size_t expected = (_expected); \ void *p = alloc; \ KUNIT_EXPECT_TRUE_MSG(test, p != NULL, #alloc " failed?!\n"); \ KUNIT_EXPECT_BOS(test, p, SIZE_MAX, #alloc); \ KUNIT_EXPECT_BDOS(test, p, expected, #alloc); \ free; \ } while (0) /* Assortment of constant-value kinda-edge cases. */ #define CONST_TEST_BODY(TEST_alloc) do { \ /* Special-case vmalloc()-family to skip 0-sized allocs. */ \ if (strcmp(#TEST_alloc, "TEST_vmalloc") != 0) \ TEST_alloc(check_const, 0, 0); \ TEST_alloc(check_const, 1, 1); \ TEST_alloc(check_const, 128, 128); \ TEST_alloc(check_const, 1023, 1023); \ TEST_alloc(check_const, 1025, 1025); \ TEST_alloc(check_const, 4096, 4096); \ TEST_alloc(check_const, 4097, 4097); \ } while (0) static volatile size_t zero_size; static volatile size_t unknown_size = 50; #if !__has_builtin(__builtin_dynamic_object_size) #define DYNAMIC_TEST_BODY(TEST_alloc) \ kunit_skip(test, "Compiler is missing __builtin_dynamic_object_size() support\n") #else #define DYNAMIC_TEST_BODY(TEST_alloc) do { \ size_t size = unknown_size; \ \ /* \ * Expected size is "size" in each test, before it is then \ * internally incremented in each test. Requires we disable \ * -Wunsequenced. \ */ \ TEST_alloc(check_dynamic, size, size++); \ /* Make sure incrementing actually happened. */ \ KUNIT_EXPECT_NE(test, size, unknown_size); \ } while (0) #endif #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator) \ static void alloc_size_##allocator##_const_test(struct kunit *test) \ { \ CONST_TEST_BODY(TEST_##allocator); \ } \ static void alloc_size_##allocator##_dynamic_test(struct kunit *test) \ { \ DYNAMIC_TEST_BODY(TEST_##allocator); \ } #define TEST_kmalloc(checker, expected_size, alloc_size) do { \ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ void *orig; \ size_t len; \ \ checker(expected_size, kmalloc(alloc_size, gfp), \ kfree(p)); \ checker(expected_size, \ kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, kzalloc(alloc_size, gfp), \ kfree(p)); \ checker(expected_size, \ kzalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, kcalloc(1, alloc_size, gfp), \ kfree(p)); \ checker(expected_size, kcalloc(alloc_size, 1, gfp), \ kfree(p)); \ checker(expected_size, \ kcalloc_node(1, alloc_size, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, \ kcalloc_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, kmalloc_array(1, alloc_size, gfp), \ kfree(p)); \ checker(expected_size, kmalloc_array(alloc_size, 1, gfp), \ kfree(p)); \ checker(expected_size, \ kmalloc_array_node(1, alloc_size, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, \ kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE), \ kfree(p)); \ checker(expected_size, __kmalloc(alloc_size, gfp), \ kfree(p)); \ checker(expected_size, \ __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE), \ kfree(p)); \ \ orig = kmalloc(alloc_size, gfp); \ KUNIT_EXPECT_TRUE(test, orig != NULL); \ checker((expected_size) * 2, \ krealloc(orig, (alloc_size) * 2, gfp), \ kfree(p)); \ orig = kmalloc(alloc_size, gfp); \ KUNIT_EXPECT_TRUE(test, orig != NULL); \ checker((expected_size) * 2, \ krealloc_array(orig, 1, (alloc_size) * 2, gfp), \ kfree(p)); \ orig = kmalloc(alloc_size, gfp); \ KUNIT_EXPECT_TRUE(test, orig != NULL); \ checker((expected_size) * 2, \ krealloc_array(orig, (alloc_size) * 2, 1, gfp), \ kfree(p)); \ \ len = 11; \ /* Using memdup() with fixed size, so force unknown length. */ \ if (!__builtin_constant_p(expected_size)) \ len += zero_size; \ checker(len, kmemdup("hello there", len, gfp), kfree(p)); \ } while (0) DEFINE_ALLOC_SIZE_TEST_PAIR(kmalloc) /* Sizes are in pages, not bytes. */ #define TEST_vmalloc(checker, expected_pages, alloc_pages) do { \ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ checker((expected_pages) * PAGE_SIZE, \ vmalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ vzalloc((alloc_pages) * PAGE_SIZE), vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ __vmalloc((alloc_pages) * PAGE_SIZE, gfp), vfree(p)); \ } while (0) DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc) /* Sizes are in pages (and open-coded for side-effects), not bytes. */ #define TEST_kvmalloc(checker, expected_pages, alloc_pages) do { \ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ size_t prev_size; \ void *orig; \ \ checker((expected_pages) * PAGE_SIZE, \ kvmalloc((alloc_pages) * PAGE_SIZE, gfp), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvzalloc((alloc_pages) * PAGE_SIZE, gfp), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp), \ vfree(p)); \ checker((expected_pages) * PAGE_SIZE, \ kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp), \ vfree(p)); \ \ prev_size = (expected_pages) * PAGE_SIZE; \ orig = kvmalloc(prev_size, gfp); \ KUNIT_EXPECT_TRUE(test, orig != NULL); \ checker(((expected_pages) * PAGE_SIZE) * 2, \ kvrealloc(orig, prev_size, \ ((alloc_pages) * PAGE_SIZE) * 2, gfp), \ kvfree(p)); \ } while (0) DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc) #define TEST_devm_kmalloc(checker, expected_size, alloc_size) do { \ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; \ const char dev_name[] = "fortify-test"; \ struct device *dev; \ void *orig; \ size_t len; \ \ /* Create dummy device for devm_kmalloc()-family tests. */ \ dev = kunit_device_register(test, dev_name); \ KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev), \ "Cannot register test device\n"); \ \ checker(expected_size, devm_kmalloc(dev, alloc_size, gfp), \ devm_kfree(dev, p)); \ checker(expected_size, devm_kzalloc(dev, alloc_size, gfp), \ devm_kfree(dev, p)); \ checker(expected_size, \ devm_kmalloc_array(dev, 1, alloc_size, gfp), \ devm_kfree(dev, p)); \ checker(expected_size, \ devm_kmalloc_array(dev, alloc_size, 1, gfp), \ devm_kfree(dev, p)); \ checker(expected_size, \ devm_kcalloc(dev, 1, alloc_size, gfp), \ devm_kfree(dev, p)); \ checker(expected_size, \ devm_kcalloc(dev, alloc_size, 1, gfp), \ devm_kfree(dev, p)); \ \ orig = devm_kmalloc(dev, alloc_size, gfp); \ KUNIT_EXPECT_TRUE(test, orig != NULL); \ checker((expected_size) * 2, \ devm_krealloc(dev, orig, (alloc_size) * 2, gfp), \ devm_kfree(dev, p)); \ \ len = 4; \ /* Using memdup() with fixed size, so force unknown length. */ \ if (!__builtin_constant_p(expected_size)) \ len += zero_size; \ checker(len, devm_kmemdup(dev, "Ohai", len, gfp), \ devm_kfree(dev, p)); \ \ kunit_device_unregister(test, dev); \ } while (0) DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc) /* * We can't have an array at the end of a structure or else * builds without -fstrict-flex-arrays=3 will report them as * being an unknown length. Additionally, add bytes before * and after the string to catch over/underflows if tests * fail. */ struct fortify_padding { unsigned long bytes_before; char buf[32]; unsigned long bytes_after; }; /* Force compiler into not being able to resolve size at compile-time. */ static volatile int unconst; static void strlen_test(struct kunit *test) { struct fortify_padding pad = { }; int i, end = sizeof(pad.buf) - 1; /* Fill 31 bytes with valid characters. */ for (i = 0; i < sizeof(pad.buf) - 1; i++) pad.buf[i] = i + '0'; /* Trailing bytes are still %NUL. */ KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* String is terminated, so strlen() is valid. */ KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Make string unterminated, and recount. */ pad.buf[end] = 'A'; end = sizeof(pad.buf); KUNIT_EXPECT_EQ(test, strlen(pad.buf), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); } static void strnlen_test(struct kunit *test) { struct fortify_padding pad = { }; int i, end = sizeof(pad.buf) - 1; /* Fill 31 bytes with valid characters. */ for (i = 0; i < sizeof(pad.buf) - 1; i++) pad.buf[i] = i + '0'; /* Trailing bytes are still %NUL. */ KUNIT_EXPECT_EQ(test, pad.buf[end], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* String is terminated, so strnlen() is valid. */ KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf)), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* A truncated strnlen() will be safe, too. */ KUNIT_EXPECT_EQ(test, strnlen(pad.buf, sizeof(pad.buf) / 2), sizeof(pad.buf) / 2); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Make string unterminated, and recount. */ pad.buf[end] = 'A'; end = sizeof(pad.buf); /* Reading beyond with strncpy() will fail. */ KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 1), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end + 2), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); /* Early-truncated is safe still, though. */ KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); end = sizeof(pad.buf) / 2; KUNIT_EXPECT_EQ(test, strnlen(pad.buf, end), end); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); } static void strcpy_test(struct kunit *test) { struct fortify_padding pad = { }; char src[sizeof(pad.buf) + 1] = { }; int i; /* Fill 31 bytes with valid characters. */ for (i = 0; i < sizeof(src) - 2; i++) src[i] = i + '0'; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strcpy() 1 less than of max size. */ KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Only last byte should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); src[sizeof(src) - 2] = 'A'; /* But now we trip the overflow checking. */ KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); /* Trailing %NUL -- thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); src[sizeof(src) - 1] = 'A'; /* And for sure now, two bytes past. */ KUNIT_ASSERT_TRUE(test, strcpy(pad.buf, src) == pad.buf); /* * Which trips both the strlen() on the unterminated src, * and the resulting copy attempt. */ KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); /* Trailing %NUL -- thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void strncpy_test(struct kunit *test) { struct fortify_padding pad = { }; char src[] = "Copy me fully into a small buffer and I will overflow!"; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strncpy() 1 less than of max size. */ KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, sizeof(pad.buf) + unconst - 1) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Only last byte should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* Legitimate (though unterminated) max-size strncpy. */ KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, sizeof(pad.buf) + unconst) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* No trailing %NUL -- thanks strncpy API. */ KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* But we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Now verify that FORTIFY is working... */ KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, sizeof(pad.buf) + unconst + 1) == pad.buf); /* Should catch the overflow. */ KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* And further... */ KUNIT_ASSERT_TRUE(test, strncpy(pad.buf, src, sizeof(pad.buf) + unconst + 2) == pad.buf); /* Should catch the overflow. */ KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void strscpy_test(struct kunit *test) { struct fortify_padding pad = { }; char src[] = "Copy me fully into a small buffer and I will overflow!"; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strscpy() 1 less than of max size. */ KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, sizeof(pad.buf) + unconst - 1), -E2BIG); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Keeping space for %NUL, last two bytes should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* Legitimate max-size strscpy. */ KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, sizeof(pad.buf) + unconst), -E2BIG); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* A trailing %NUL will exist. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* Now verify that FORTIFY is working... */ KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, sizeof(pad.buf) + unconst + 1), -E2BIG); /* Should catch the overflow. */ KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* And much further... */ KUNIT_ASSERT_EQ(test, strscpy(pad.buf, src, sizeof(src) * 2 + unconst), -E2BIG); /* Should catch the overflow. */ KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); /* And we will not have gone beyond. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void strcat_test(struct kunit *test) { struct fortify_padding pad = { }; char src[sizeof(pad.buf) / 2] = { }; char one[] = "A"; char two[] = "BC"; int i; /* Fill 15 bytes with valid characters. */ for (i = 0; i < sizeof(src) - 1; i++) src[i] = i + 'A'; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strcat() using less than half max size. */ KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Legitimate strcat() now 2 bytes shy of end. */ KUNIT_ASSERT_TRUE(test, strcat(pad.buf, src) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last two bytes should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* Add one more character to the end. */ KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last byte should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* And this one char will overflow. */ KUNIT_ASSERT_TRUE(test, strcat(pad.buf, one) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* And adding two will overflow more. */ KUNIT_ASSERT_TRUE(test, strcat(pad.buf, two) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void strncat_test(struct kunit *test) { struct fortify_padding pad = { }; char src[sizeof(pad.buf)] = { }; int i, partial; /* Fill 31 bytes with valid characters. */ partial = sizeof(src) / 2 - 1; for (i = 0; i < partial; i++) src[i] = i + 'A'; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strncat() using less than half max size. */ KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Legitimate strncat() now 2 bytes shy of end. */ KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, partial) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last two bytes should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* Add one more character to the end. */ KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last byte should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* And this one char will overflow. */ KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* And adding two will overflow more. */ KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 2) == pad.buf); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Force an unterminated destination, and overflow. */ pad.buf[sizeof(pad.buf) - 1] = 'A'; KUNIT_ASSERT_TRUE(test, strncat(pad.buf, src, 1) == pad.buf); /* This will have tripped both strlen() and strcat(). */ KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* But we should not go beyond the end. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void strlcat_test(struct kunit *test) { struct fortify_padding pad = { }; char src[sizeof(pad.buf)] = { }; int i, partial; int len = sizeof(pad.buf) + unconst; /* Fill 15 bytes with valid characters. */ partial = sizeof(src) / 2 - 1; for (i = 0; i < partial; i++) src[i] = i + 'A'; /* Destination is %NUL-filled to start with. */ KUNIT_EXPECT_EQ(test, pad.bytes_before, 0); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Legitimate strlcat() using less than half max size. */ KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Legitimate strlcat() now 2 bytes shy of end. */ KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len), partial * 2); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last two bytes should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* Add one more character to the end. */ KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "Q", len), partial * 2 + 1); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0); /* Last byte should be %NUL */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* And this one char will overflow. */ KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "V", len * 2), len); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* And adding two will overflow more. */ KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "QQ", len * 2), len + 1); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); /* Last byte should be %NUL thanks to FORTIFY. */ KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Force an unterminated destination, and overflow. */ pad.buf[sizeof(pad.buf) - 1] = 'A'; KUNIT_ASSERT_EQ(test, strlcat(pad.buf, "TT", len * 2), len + 2); /* This will have tripped both strlen() and strlcat(). */ KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 1], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 2], '\0'); KUNIT_EXPECT_NE(test, pad.buf[sizeof(pad.buf) - 3], '\0'); /* But we should not go beyond the end. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); /* Force an unterminated source, and overflow. */ memset(src, 'B', sizeof(src)); pad.buf[sizeof(pad.buf) - 1] = '\0'; KUNIT_ASSERT_EQ(test, strlcat(pad.buf, src, len * 3), len - 1 + sizeof(src)); /* This will have tripped both strlen() and strlcat(). */ KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); KUNIT_EXPECT_EQ(test, fortify_write_overflows, 3); KUNIT_EXPECT_EQ(test, pad.buf[sizeof(pad.buf) - 1], '\0'); /* But we should not go beyond the end. */ KUNIT_EXPECT_EQ(test, pad.bytes_after, 0); } static void memscan_test(struct kunit *test) { char haystack[] = "Where oh where is my memory range?"; char *mem = haystack + strlen("Where oh where is "); char needle = 'm'; size_t len = sizeof(haystack) + unconst; KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len), mem); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Catch too-large range. */ KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len + 1), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_ASSERT_PTR_EQ(test, memscan(haystack, needle, len * 2), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); } static void memchr_test(struct kunit *test) { char haystack[] = "Where oh where is my memory range?"; char *mem = haystack + strlen("Where oh where is "); char needle = 'm'; size_t len = sizeof(haystack) + unconst; KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len), mem); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Catch too-large range. */ KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len + 1), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_ASSERT_PTR_EQ(test, memchr(haystack, needle, len * 2), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); } static void memchr_inv_test(struct kunit *test) { char haystack[] = "Where oh where is my memory range?"; char *mem = haystack + 1; char needle = 'W'; size_t len = sizeof(haystack) + unconst; /* Normal search is okay. */ KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len), mem); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Catch too-large range. */ KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len + 1), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_ASSERT_PTR_EQ(test, memchr_inv(haystack, needle, len * 2), NULL); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); } static void memcmp_test(struct kunit *test) { char one[] = "My mind is going ..."; char two[] = "My mind is going ... I can feel it."; size_t one_len = sizeof(one) + unconst - 1; size_t two_len = sizeof(two) + unconst - 1; /* We match the first string (ignoring the %NUL). */ KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len), 0); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Still in bounds, but no longer matching. */ KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 1), -32); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); /* Catch too-large ranges. */ KUNIT_ASSERT_EQ(test, memcmp(one, two, one_len + 2), INT_MIN); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); KUNIT_ASSERT_EQ(test, memcmp(two, one, two_len + 2), INT_MIN); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); } static void kmemdup_test(struct kunit *test) { char src[] = "I got Doom running on it!"; char *copy; size_t len = sizeof(src) + unconst; /* Copy is within bounds. */ copy = kmemdup(src, len, GFP_KERNEL); KUNIT_EXPECT_NOT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); kfree(copy); /* Without %NUL. */ copy = kmemdup(src, len - 1, GFP_KERNEL); KUNIT_EXPECT_NOT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); kfree(copy); /* Tiny bounds. */ copy = kmemdup(src, 1, GFP_KERNEL); KUNIT_EXPECT_NOT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0); kfree(copy); /* Out of bounds by 1 byte. */ copy = kmemdup(src, len + 1, GFP_KERNEL); KUNIT_EXPECT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1); kfree(copy); /* Way out of bounds. */ copy = kmemdup(src, len * 2, GFP_KERNEL); KUNIT_EXPECT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2); kfree(copy); /* Starting offset causing out of bounds. */ copy = kmemdup(src + 1, len, GFP_KERNEL); KUNIT_EXPECT_NULL(test, copy); KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3); kfree(copy); } static int fortify_test_init(struct kunit *test) { if (!IS_ENABLED(CONFIG_FORTIFY_SOURCE)) kunit_skip(test, "Not built with CONFIG_FORTIFY_SOURCE=y"); fortify_read_overflows = 0; kunit_add_named_resource(test, NULL, NULL, &read_resource, "fortify_read_overflows", &fortify_read_overflows); fortify_write_overflows = 0; kunit_add_named_resource(test, NULL, NULL, &write_resource, "fortify_write_overflows", &fortify_write_overflows); return 0; } static struct kunit_case fortify_test_cases[] = { KUNIT_CASE(known_sizes_test), KUNIT_CASE(control_flow_split_test), KUNIT_CASE(alloc_size_kmalloc_const_test), KUNIT_CASE(alloc_size_kmalloc_dynamic_test), KUNIT_CASE(alloc_size_vmalloc_const_test), KUNIT_CASE(alloc_size_vmalloc_dynamic_test), KUNIT_CASE(alloc_size_kvmalloc_const_test), KUNIT_CASE(alloc_size_kvmalloc_dynamic_test), KUNIT_CASE(alloc_size_devm_kmalloc_const_test), KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test), KUNIT_CASE(strlen_test), KUNIT_CASE(strnlen_test), KUNIT_CASE(strcpy_test), KUNIT_CASE(strncpy_test), KUNIT_CASE(strscpy_test), KUNIT_CASE(strcat_test), KUNIT_CASE(strncat_test), KUNIT_CASE(strlcat_test), /* skip memset: performs bounds checking on whole structs */ /* skip memcpy: still using warn-and-overwrite instead of hard-fail */ KUNIT_CASE(memscan_test), KUNIT_CASE(memchr_test), KUNIT_CASE(memchr_inv_test), KUNIT_CASE(memcmp_test), KUNIT_CASE(kmemdup_test), {} }; static struct kunit_suite fortify_test_suite = { .name = "fortify", .init = fortify_test_init, .test_cases = fortify_test_cases, }; kunit_test_suite(fortify_test_suite); MODULE_LICENSE("GPL");
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