| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * Runtime test cases for CONFIG_FORTIFY_SOURCE. For additional memcpy() |
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| 4 | * testing see FORTIFY_MEM_* tests in LKDTM (drivers/misc/lkdtm/fortify.c). |
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| 5 | * |
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| 6 | * For corner cases with UBSAN, try testing with: |
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| 7 | * |
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| 8 | * ./tools/testing/kunit/kunit.py run --arch=x86_64 \ |
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| 9 | * --kconfig_add CONFIG_FORTIFY_SOURCE=y \ |
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| 10 | * --kconfig_add CONFIG_UBSAN=y \ |
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| 11 | * --kconfig_add CONFIG_UBSAN_TRAP=y \ |
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| 12 | * --kconfig_add CONFIG_UBSAN_BOUNDS=y \ |
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| 13 | * --kconfig_add CONFIG_UBSAN_LOCAL_BOUNDS=y \ |
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| 14 | * --make_options LLVM=1 fortify |
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| 15 | */ |
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| 16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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| 17 | |
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| 18 | /* We don't need to fill dmesg with the fortify WARNs during testing. */ |
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| 19 | #ifdef DEBUG |
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| 20 | # define FORTIFY_REPORT_KUNIT(x...) __fortify_report(x) |
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| 21 | # define FORTIFY_WARN_KUNIT(x...) WARN_ONCE(x) |
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| 22 | #else |
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| 23 | # define FORTIFY_REPORT_KUNIT(x...) do { } while (0) |
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| 24 | # define FORTIFY_WARN_KUNIT(x...) do { } while (0) |
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| 25 | #endif |
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| 26 | |
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| 27 | /* Redefine fortify_panic() to track failures. */ |
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| 28 | void fortify_add_kunit_error(int write); |
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| 29 | #define fortify_panic(func, write, avail, size, retfail) do { \ |
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| 30 | FORTIFY_REPORT_KUNIT(FORTIFY_REASON(func, write), avail, size); \ |
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| 31 | fortify_add_kunit_error(write); \ |
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| 32 | return (retfail); \ |
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| 33 | } while (0) |
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| 34 | |
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| 35 | /* Redefine fortify_warn_once() to track memcpy() failures. */ |
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| 36 | #define fortify_warn_once(chk_func, x...) do { \ |
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| 37 | bool __result = chk_func; \ |
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| 38 | FORTIFY_WARN_KUNIT(__result, x); \ |
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| 39 | if (__result) \ |
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| 40 | fortify_add_kunit_error(1); \ |
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| 41 | } while (0) |
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| 42 | |
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| 43 | #include <kunit/device.h> |
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| 44 | #include <kunit/test.h> |
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| 45 | #include <kunit/test-bug.h> |
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| 46 | #include <linux/device.h> |
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| 47 | #include <linux/slab.h> |
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| 48 | #include <linux/string.h> |
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| 49 | #include <linux/vmalloc.h> |
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| 50 | |
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| 51 | /* Handle being built without CONFIG_FORTIFY_SOURCE */ |
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| 52 | #ifndef __compiletime_strlen |
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| 53 | # define __compiletime_strlen __builtin_strlen |
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| 54 | #endif |
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| 55 | |
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| 56 | static struct kunit_resource read_resource; |
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| 57 | static struct kunit_resource write_resource; |
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| 58 | static int fortify_read_overflows; |
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| 59 | static int fortify_write_overflows; |
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| 60 | |
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| 61 | static const char array_of_10[] = "this is 10" ; |
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| 62 | static const char *ptr_of_11 = "this is 11!" ; |
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| 63 | static const char * const unchanging_12 = "this is 12!!" ; |
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| 64 | static char array_unknown[] = "compiler thinks I might change" ; |
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| 65 | |
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| 66 | void fortify_add_kunit_error(int write) |
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| 67 | { |
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| 68 | struct kunit_resource *resource; |
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| 69 | struct kunit *current_test; |
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| 70 | |
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| 71 | current_test = kunit_get_current_test(); |
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| 72 | if (!current_test) |
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| 73 | return; |
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| 74 | |
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| 75 | resource = kunit_find_named_resource(test: current_test, |
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| 76 | name: write ? "fortify_write_overflows" |
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| 77 | : "fortify_read_overflows" ); |
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| 78 | if (!resource) |
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| 79 | return; |
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| 80 | |
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| 81 | (*(int *)resource->data)++; |
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| 82 | kunit_put_resource(res: resource); |
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| 83 | } |
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| 84 | |
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| 85 | static void fortify_test_known_sizes(struct kunit *test) |
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| 86 | { |
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| 87 | char stack[80] = "Test!" ; |
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| 88 | |
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| 89 | KUNIT_EXPECT_FALSE(test, __is_constexpr(__builtin_strlen(stack))); |
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| 90 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(stack), 5); |
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| 91 | |
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| 92 | KUNIT_EXPECT_TRUE(test, __is_constexpr(__builtin_strlen("88888888" ))); |
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| 93 | KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888" ), 8); |
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| 94 | |
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| 95 | KUNIT_EXPECT_TRUE(test, __is_constexpr(__builtin_strlen(array_of_10))); |
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| 96 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10); |
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| 97 | |
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| 98 | KUNIT_EXPECT_FALSE(test, __is_constexpr(__builtin_strlen(ptr_of_11))); |
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| 99 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(ptr_of_11), 11); |
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| 100 | |
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| 101 | KUNIT_EXPECT_TRUE(test, __is_constexpr(__builtin_strlen(unchanging_12))); |
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| 102 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(unchanging_12), 12); |
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| 103 | |
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| 104 | KUNIT_EXPECT_FALSE(test, __is_constexpr(__builtin_strlen(array_unknown))); |
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| 105 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_unknown), SIZE_MAX); |
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| 106 | |
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| 107 | /* Externally defined and dynamically sized string pointer: */ |
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| 108 | KUNIT_EXPECT_FALSE(test, __is_constexpr(__builtin_strlen(test->name))); |
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| 109 | KUNIT_EXPECT_EQ(test, __compiletime_strlen(test->name), SIZE_MAX); |
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| 110 | } |
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| 111 | |
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| 112 | /* This is volatile so the optimizer can't perform DCE below. */ |
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| 113 | static volatile int pick; |
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| 114 | |
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| 115 | /* Not inline to keep optimizer from figuring out which string we want. */ |
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| 116 | static noinline size_t want_minus_one(int pick) |
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| 117 | { |
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| 118 | const char *str; |
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| 119 | |
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| 120 | switch (pick) { |
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| 121 | case 1: |
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| 122 | str = "4444" ; |
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| 123 | break; |
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| 124 | case 2: |
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| 125 | str = "333" ; |
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| 126 | break; |
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| 127 | default: |
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| 128 | str = "1" ; |
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| 129 | break; |
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| 130 | } |
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| 131 | return __compiletime_strlen(str); |
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| 132 | } |
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| 133 | |
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| 134 | static void fortify_test_control_flow_split(struct kunit *test) |
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| 135 | { |
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| 136 | KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX); |
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| 137 | } |
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| 138 | |
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| 139 | #define KUNIT_EXPECT_BOS(test, p, expected, name) \ |
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| 140 | KUNIT_EXPECT_EQ_MSG(test, __builtin_object_size(p, 1), \ |
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| 141 | expected, \ |
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| 142 | "__alloc_size() not working with __bos on " name "\n") |
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| 143 | |
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| 144 | #if !__has_builtin(__builtin_dynamic_object_size) |
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| 145 | #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ |
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| 146 | /* Silence "unused variable 'expected'" warning. */ \ |
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| 147 | KUNIT_EXPECT_EQ(test, expected, expected) |
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| 148 | #else |
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| 149 | #define KUNIT_EXPECT_BDOS(test, p, expected, name) \ |
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| 150 | KUNIT_EXPECT_EQ_MSG(test, __builtin_dynamic_object_size(p, 1), \ |
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| 151 | expected, \ |
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| 152 | "__alloc_size() not working with __bdos on " name "\n") |
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| 153 | #endif |
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| 154 | |
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| 155 | /* If the execpted size is a constant value, __bos can see it. */ |
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| 156 | #define check_const(_expected, alloc, free) do { \ |
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| 157 | size_t |
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