// SPDX-License-Identifier: GPL-2.0-only /* * * Copyright (c) 2014 Samsung Electronics Co., Ltd. * Author: Andrey Ryabinin */ #define pr_fmt(fmt) "kasan: test: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "kasan.h" #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE) static bool multishot; /* Fields set based on lines observed in the console. */ static struct { bool report_found; bool async_fault; } test_status; /* * Some tests use these global variables to store return values from function * calls that could otherwise be eliminated by the compiler as dead code. */ void *kasan_ptr_result; int kasan_int_result; /* Probe for console output: obtains test_status lines of interest. */ static void probe_console(void *ignore, const char *buf, size_t len) { if (strnstr(buf, "BUG: KASAN: ", len)) WRITE_ONCE(test_status.report_found, true); else if (strnstr(buf, "Asynchronous fault: ", len)) WRITE_ONCE(test_status.async_fault, true); } static int kasan_suite_init(struct kunit_suite *suite) { if (!kasan_enabled()) { pr_err("Can't run KASAN tests with KASAN disabled"); return -1; } /* Stop failing KUnit tests on KASAN reports. */ kasan_kunit_test_suite_start(); /* * Temporarily enable multi-shot mode. Otherwise, KASAN would only * report the first detected bug and panic the kernel if panic_on_warn * is enabled. */ multishot = kasan_save_enable_multi_shot(); register_trace_console(probe_console, NULL); return 0; } static void kasan_suite_exit(struct kunit_suite *suite) { kasan_kunit_test_suite_end(); kasan_restore_multi_shot(multishot); unregister_trace_console(probe_console, NULL); tracepoint_synchronize_unregister(); } static void kasan_test_exit(struct kunit *test) { KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found)); } /** * KUNIT_EXPECT_KASAN_FAIL - check that the executed expression produces a * KASAN report; causes a KUnit test failure otherwise. * * @test: Currently executing KUnit test. * @expression: Expression that must produce a KASAN report. * * For hardware tag-based KASAN, when a synchronous tag fault happens, tag * checking is auto-disabled. When this happens, this test handler reenables * tag checking. As tag checking can be only disabled or enabled per CPU, * this handler disables migration (preemption). * * Since the compiler doesn't see that the expression can change the test_status * fields, it can reorder or optimize away the accesses to those fields. * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the * expression to prevent that. * * In between KUNIT_EXPECT_KASAN_FAIL checks, test_status.report_found is kept * as false. This allows detecting KASAN reports that happen outside of the * checks by asserting !test_status.report_found at the start of * KUNIT_EXPECT_KASAN_FAIL and in kasan_test_exit. */ #define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \ if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \ kasan_sync_fault_possible()) \ migrate_disable(); \ KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found)); \ barrier(); \ expression; \ barrier(); \ if (kasan_async_fault_possible()) \ kasan_force_async_fault(); \ if (!READ_ONCE(test_status.report_found)) { \ KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure " \ "expected in \"" #expression \ "\", but none occurred"); \ } \ if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \ kasan_sync_fault_possible()) { \ if (READ_ONCE(test_status.report_found) && \ !READ_ONCE(test_status.async_fault)) \ kasan_enable_hw_tags(); \ migrate_enable(); \ } \ WRITE_ONCE(test_status.report_found, false); \ WRITE_ONCE(test_status.async_fault, false); \ } while (0) #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \ if (!IS_ENABLED(config)) \ kunit_skip((test), "Test requires " #config "=y"); \ } while (0) #define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do { \ if (IS_ENABLED(config)) \ kunit_skip((test), "Test requires " #config "=n"); \ } while (0) #define KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test) do { \ if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) \ break; /* No compiler instrumentation. */ \ if (IS_ENABLED(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX)) \ break; /* Should always be instrumented! */ \ if (IS_ENABLED(CONFIG_GENERIC_ENTRY)) \ kunit_skip((test), "Test requires checked mem*()"); \ } while (0) static void kmalloc_oob_right(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE - 5; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); /* * An unaligned access past the requested kmalloc size. * Only generic KASAN can precisely detect these. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x'); /* * An aligned access into the first out-of-bounds granule that falls * within the aligned kmalloc object. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y'); /* Out-of-bounds access past the aligned kmalloc object. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size + KASAN_GRANULE_SIZE + 5]); kfree(ptr); } static void kmalloc_oob_left(struct kunit *test) { char *ptr; size_t size = 15; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1)); kfree(ptr); } static void kmalloc_node_oob_right(struct kunit *test) { char *ptr; size_t size = 4096; ptr = kmalloc_node(size, GFP_KERNEL, 0); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]); kfree(ptr); } /* * Check that KASAN detects an out-of-bounds access for a big object allocated * via kmalloc(). But not as big as to trigger the page_alloc fallback. */ static void kmalloc_big_oob_right(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE - 256; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0); kfree(ptr); } /* * The kmalloc_large_* tests below use kmalloc() to allocate a memory chunk * that does not fit into the largest slab cache and therefore is allocated via * the page_alloc fallback. */ static void kmalloc_large_oob_right(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0); kfree(ptr); } static void kmalloc_large_uaf(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]); } static void kmalloc_large_invalid_free(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1)); } static void page_alloc_oob_right(struct kunit *test) { char *ptr; struct page *pages; size_t order = 4; size_t size = (1UL << (PAGE_SHIFT + order)); /* * With generic KASAN page allocations have no redzones, thus * out-of-bounds detection is not guaranteed. * See https://bugzilla.kernel.org/show_bug.cgi?id=210503. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); pages = alloc_pages(GFP_KERNEL, order); ptr = page_address(pages); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]); free_pages((unsigned long)ptr, order); } static void page_alloc_uaf(struct kunit *test) { char *ptr; struct page *pages; size_t order = 4; pages = alloc_pages(GFP_KERNEL, order); ptr = page_address(pages); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); free_pages((unsigned long)ptr, order); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]); } static void krealloc_more_oob_helper(struct kunit *test, size_t size1, size_t size2) { char *ptr1, *ptr2; size_t middle; KUNIT_ASSERT_LT(test, size1, size2); middle = size1 + (size2 - size1) / 2; ptr1 = kmalloc(size1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = krealloc(ptr1, size2, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); /* Suppress -Warray-bounds warnings. */ OPTIMIZER_HIDE_VAR(ptr2); /* All offsets up to size2 must be accessible. */ ptr2[size1 - 1] = 'x'; ptr2[size1] = 'x'; ptr2[middle] = 'x'; ptr2[size2 - 1] = 'x'; /* Generic mode is precise, so unaligned size2 must be inaccessible. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x'); /* For all modes first aligned offset after size2 must be inaccessible. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x'); kfree(ptr2); } static void krealloc_less_oob_helper(struct kunit *test, size_t size1, size_t size2) { char *ptr1, *ptr2; size_t middle; KUNIT_ASSERT_LT(test, size2, size1); middle = size2 + (size1 - size2) / 2; ptr1 = kmalloc(size1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = krealloc(ptr1, size2, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); /* Suppress -Warray-bounds warnings. */ OPTIMIZER_HIDE_VAR(ptr2); /* Must be accessible for all modes. */ ptr2[size2 - 1] = 'x'; /* Generic mode is precise, so unaligned size2 must be inaccessible. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x'); /* For all modes first aligned offset after size2 must be inaccessible. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x'); /* * For all modes all size2, middle, and size1 should land in separate * granules and thus the latter two offsets should be inaccessible. */ KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE), round_down(middle, KASAN_GRANULE_SIZE)); KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE), round_down(size1, KASAN_GRANULE_SIZE)); KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x'); KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x'); KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x'); kfree(ptr2); } static void krealloc_more_oob(struct kunit *test) { krealloc_more_oob_helper(test, 201, 235); } static void krealloc_less_oob(struct kunit *test) { krealloc_less_oob_helper(test, 235, 201); } static void krealloc_large_more_oob(struct kunit *test) { krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201, KMALLOC_MAX_CACHE_SIZE + 235); } static void krealloc_large_less_oob(struct kunit *test) { krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235, KMALLOC_MAX_CACHE_SIZE + 201); } /* * Check that krealloc() detects a use-after-free, returns NULL, * and doesn't unpoison the freed object. */ static void krealloc_uaf(struct kunit *test) { char *ptr1, *ptr2; int size1 = 201; int size2 = 235; ptr1 = kmalloc(size1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); kfree(ptr1); KUNIT_EXPECT_KASAN_FAIL(test, ptr2 = krealloc(ptr1, size2, GFP_KERNEL)); KUNIT_ASSERT_NULL(test, ptr2); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)ptr1); } static void kmalloc_oob_16(struct kunit *test) { struct { u64 words[2]; } *ptr1, *ptr2; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); /* This test is specifically crafted for the generic mode. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); /* RELOC_HIDE to prevent gcc from warning about short alloc */ ptr1 = RELOC_HIDE(kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL), 0); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); OPTIMIZER_HIDE_VAR(ptr1); OPTIMIZER_HIDE_VAR(ptr2); KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2); kfree(ptr1); kfree(ptr2); } static void kmalloc_uaf_16(struct kunit *test) { struct { u64 words[2]; } *ptr1, *ptr2; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr1 = kmalloc(sizeof(*ptr1), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); kfree(ptr2); KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2); kfree(ptr1); } /* * Note: in the memset tests below, the written range touches both valid and * invalid memory. This makes sure that the instrumentation does not only check * the starting address but the whole range. */ static void kmalloc_oob_memset_2(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE; size_t memset_size = 2; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); OPTIMIZER_HIDE_VAR(memset_size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, memset_size)); kfree(ptr); } static void kmalloc_oob_memset_4(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE; size_t memset_size = 4; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); OPTIMIZER_HIDE_VAR(memset_size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, memset_size)); kfree(ptr); } static void kmalloc_oob_memset_8(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE; size_t memset_size = 8; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); OPTIMIZER_HIDE_VAR(memset_size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, memset_size)); kfree(ptr); } static void kmalloc_oob_memset_16(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE; size_t memset_size = 16; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); OPTIMIZER_HIDE_VAR(memset_size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, memset_size)); kfree(ptr); } static void kmalloc_oob_in_memset(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + KASAN_GRANULE_SIZE)); kfree(ptr); } static void kmalloc_memmove_negative_size(struct kunit *test) { char *ptr; size_t size = 64; size_t invalid_size = -2; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); /* * Hardware tag-based mode doesn't check memmove for negative size. * As a result, this test introduces a side-effect memory corruption, * which can result in a crash. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset((char *)ptr, 0, 64); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(invalid_size); KUNIT_EXPECT_KASAN_FAIL(test, memmove((char *)ptr, (char *)ptr + 4, invalid_size)); kfree(ptr); } static void kmalloc_memmove_invalid_size(struct kunit *test) { char *ptr; size_t size = 64; size_t invalid_size = size; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset((char *)ptr, 0, 64); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(invalid_size); KUNIT_EXPECT_KASAN_FAIL(test, memmove((char *)ptr, (char *)ptr + 4, invalid_size)); kfree(ptr); } static void kmalloc_uaf(struct kunit *test) { char *ptr; size_t size = 10; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[8]); } static void kmalloc_uaf_memset(struct kunit *test) { char *ptr; size_t size = 33; KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test); /* * Only generic KASAN uses quarantine, which is required to avoid a * kernel memory corruption this test causes. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size)); } static void kmalloc_uaf2(struct kunit *test) { char *ptr1, *ptr2; size_t size = 43; int counter = 0; again: ptr1 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); kfree(ptr1); ptr2 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); /* * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same. * Allow up to 16 attempts at generating different tags. */ if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) { kfree(ptr2); goto again; } KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[40]); KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2); kfree(ptr2); } /* * Check that KASAN detects use-after-free when another object was allocated in * the same slot. Relevant for the tag-based modes, which do not use quarantine. */ static void kmalloc_uaf3(struct kunit *test) { char *ptr1, *ptr2; size_t size = 100; /* This test is specifically crafted for tag-based modes. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); ptr1 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); kfree(ptr1); ptr2 = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); kfree(ptr2); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]); } static void kasan_atomics_helper(struct kunit *test, void *unsafe, void *safe) { int *i_unsafe = unsafe; KUNIT_EXPECT_KASAN_FAIL(test, READ_ONCE(*i_unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, WRITE_ONCE(*i_unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, smp_load_acquire(i_unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, smp_store_release(i_unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_read(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_set(unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_add(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_and(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_andnot(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_or(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_xor(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_xchg(unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_cmpxchg(unsafe, 21, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(unsafe, safe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(safe, unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub_and_test(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_and_test(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_and_test(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_negative(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_unless(unsafe, 21, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_not_zero(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_unless_negative(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_unless_positive(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_if_positive(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_read(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_set(unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_and(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_andnot(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_or(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xor(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xchg(unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_cmpxchg(unsafe, 21, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(unsafe, safe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(safe, unsafe, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub_and_test(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_and_test(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_and_test(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_negative(42, unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_unless(unsafe, 21, 42)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_not_zero(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_unless_negative(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_unless_positive(unsafe)); KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_if_positive(unsafe)); } static void kasan_atomics(struct kunit *test) { void *a1, *a2; /* * Just as with kasan_bitops_tags(), we allocate 48 bytes of memory such * that the following 16 bytes will make up the redzone. */ a1 = kzalloc(48, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a1); a2 = kzalloc(sizeof(atomic_long_t), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a2); /* Use atomics to access the redzone. */ kasan_atomics_helper(test, a1 + 48, a2); kfree(a1); kfree(a2); } static void kmalloc_double_kzfree(struct kunit *test) { char *ptr; size_t size = 16; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree_sensitive(ptr); KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr)); } /* Check that ksize() does NOT unpoison whole object. */ static void ksize_unpoisons_memory(struct kunit *test) { char *ptr; size_t size = 128 - KASAN_GRANULE_SIZE - 5; size_t real_size; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); real_size = ksize(ptr); KUNIT_EXPECT_GT(test, real_size, size); OPTIMIZER_HIDE_VAR(ptr); /* These accesses shouldn't trigger a KASAN report. */ ptr[0] = 'x'; ptr[size - 1] = 'x'; /* These must trigger a KASAN report. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size + 5]); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size - 1]); kfree(ptr); } /* * Check that a use-after-free is detected by ksize() and via normal accesses * after it. */ static void ksize_uaf(struct kunit *test) { char *ptr; int size = 128 - KASAN_GRANULE_SIZE; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); OPTIMIZER_HIDE_VAR(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr)); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]); } /* * The two tests below check that Generic KASAN prints auxiliary stack traces * for RCU callbacks and workqueues. The reports need to be inspected manually. * * These tests are still enabled for other KASAN modes to make sure that all * modes report bad accesses in tested scenarios. */ static struct kasan_rcu_info { int i; struct rcu_head rcu; } *global_rcu_ptr; static void rcu_uaf_reclaim(struct rcu_head *rp) { struct kasan_rcu_info *fp = container_of(rp, struct kasan_rcu_info, rcu); kfree(fp); ((volatile struct kasan_rcu_info *)fp)->i; } static void rcu_uaf(struct kunit *test) { struct kasan_rcu_info *ptr; ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); global_rcu_ptr = rcu_dereference_protected( (struct kasan_rcu_info __rcu *)ptr, NULL); KUNIT_EXPECT_KASAN_FAIL(test, call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim); rcu_barrier()); } static void workqueue_uaf_work(struct work_struct *work) { kfree(work); } static void workqueue_uaf(struct kunit *test) { struct workqueue_struct *workqueue; struct work_struct *work; workqueue = create_workqueue("kasan_workqueue_test"); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue); work = kmalloc(sizeof(struct work_struct), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work); INIT_WORK(work, workqueue_uaf_work); queue_work(workqueue, work); destroy_workqueue(workqueue); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile struct work_struct *)work)->data); } static void kfree_via_page(struct kunit *test) { char *ptr; size_t size = 8; struct page *page; unsigned long offset; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); page = virt_to_page(ptr); offset = offset_in_page(ptr); kfree(page_address(page) + offset); } static void kfree_via_phys(struct kunit *test) { char *ptr; size_t size = 8; phys_addr_t phys; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); phys = virt_to_phys(ptr); kfree(phys_to_virt(phys)); } static void kmem_cache_oob(struct kunit *test) { char *p; size_t size = 200; struct kmem_cache *cache; cache = kmem_cache_create("test_cache", size, 0, 0, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); p = kmem_cache_alloc(cache, GFP_KERNEL); if (!p) { kunit_err(test, "Allocation failed: %s\n", __func__); kmem_cache_destroy(cache); return; } KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size + OOB_TAG_OFF]); kmem_cache_free(cache, p); kmem_cache_destroy(cache); } static void kmem_cache_double_free(struct kunit *test) { char *p; size_t size = 200; struct kmem_cache *cache; cache = kmem_cache_create("test_cache", size, 0, 0, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); p = kmem_cache_alloc(cache, GFP_KERNEL); if (!p) { kunit_err(test, "Allocation failed: %s\n", __func__); kmem_cache_destroy(cache); return; } kmem_cache_free(cache, p); KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p)); kmem_cache_destroy(cache); } static void kmem_cache_invalid_free(struct kunit *test) { char *p; size_t size = 200; struct kmem_cache *cache; cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); p = kmem_cache_alloc(cache, GFP_KERNEL); if (!p) { kunit_err(test, "Allocation failed: %s\n", __func__); kmem_cache_destroy(cache); return; } /* Trigger invalid free, the object doesn't get freed. */ KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1)); /* * Properly free the object to prevent the "Objects remaining in * test_cache on __kmem_cache_shutdown" BUG failure. */ kmem_cache_free(cache, p); kmem_cache_destroy(cache); } static void kmem_cache_rcu_uaf(struct kunit *test) { char *p; size_t size = 200; struct kmem_cache *cache; KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB_RCU_DEBUG); cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); p = kmem_cache_alloc(cache, GFP_KERNEL); if (!p) { kunit_err(test, "Allocation failed: %s\n", __func__); kmem_cache_destroy(cache); return; } *p = 1; rcu_read_lock(); /* Free the object - this will internally schedule an RCU callback. */ kmem_cache_free(cache, p); /* * We should still be allowed to access the object at this point because * the cache is SLAB_TYPESAFE_BY_RCU and we've been in an RCU read-side * critical section since before the kmem_cache_free(). */ READ_ONCE(*p); rcu_read_unlock(); /* * Wait for the RCU callback to execute; after this, the object should * have actually been freed from KASAN's perspective. */ rcu_barrier(); KUNIT_EXPECT_KASAN_FAIL(test, READ_ONCE(*p)); kmem_cache_destroy(cache); } static void empty_cache_ctor(void *object) { } static void kmem_cache_double_destroy(struct kunit *test) { struct kmem_cache *cache; /* Provide a constructor to prevent cache merging. */ cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); kmem_cache_destroy(cache); KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache)); } static void kmem_cache_accounted(struct kunit *test) { int i; char *p; size_t size = 200; struct kmem_cache *cache; cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); /* * Several allocations with a delay to allow for lazy per memcg kmem * cache creation. */ for (i = 0; i < 5; i++) { p = kmem_cache_alloc(cache, GFP_KERNEL); if (!p) goto free_cache; kmem_cache_free(cache, p); msleep(100); } free_cache: kmem_cache_destroy(cache); } static void kmem_cache_bulk(struct kunit *test) { struct kmem_cache *cache; size_t size = 200; char *p[10]; bool ret; int i; cache = kmem_cache_create("test_cache", size, 0, 0, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p); if (!ret) { kunit_err(test, "Allocation failed: %s\n", __func__); kmem_cache_destroy(cache); return; } for (i = 0; i < ARRAY_SIZE(p); i++) p[i][0] = p[i][size - 1] = 42; kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p); kmem_cache_destroy(cache); } static void *mempool_prepare_kmalloc(struct kunit *test, mempool_t *pool, size_t size) { int pool_size = 4; int ret; void *elem; memset(pool, 0, sizeof(*pool)); ret = mempool_init_kmalloc_pool(pool, pool_size, size); KUNIT_ASSERT_EQ(test, ret, 0); /* * Allocate one element to prevent mempool from freeing elements to the * underlying allocator and instead make it add them to the element * list when the tests trigger double-free and invalid-free bugs. * This allows testing KASAN annotations in add_element(). */ elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); return elem; } static struct kmem_cache *mempool_prepare_slab(struct kunit *test, mempool_t *pool, size_t size) { struct kmem_cache *cache; int pool_size = 4; int ret; cache = kmem_cache_create("test_cache", size, 0, 0, NULL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache); memset(pool, 0, sizeof(*pool)); ret = mempool_init_slab_pool(pool, pool_size, cache); KUNIT_ASSERT_EQ(test, ret, 0); /* * Do not allocate one preallocated element, as we skip the double-free * and invalid-free tests for slab mempool for simplicity. */ return cache; } static void *mempool_prepare_page(struct kunit *test, mempool_t *pool, int order) { int pool_size = 4; int ret; void *elem; memset(pool, 0, sizeof(*pool)); ret = mempool_init_page_pool(pool, pool_size, order); KUNIT_ASSERT_EQ(test, ret, 0); elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); return elem; } static void mempool_oob_right_helper(struct kunit *test, mempool_t *pool, size_t size) { char *elem; elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); OPTIMIZER_HIDE_VAR(elem); if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)&elem[size])[0]); else KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)&elem[round_up(size, KASAN_GRANULE_SIZE)])[0]); mempool_free(elem, pool); } static void mempool_kmalloc_oob_right(struct kunit *test) { mempool_t pool; size_t size = 128 - KASAN_GRANULE_SIZE - 5; void *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_oob_right_helper(test, &pool, size); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_kmalloc_large_oob_right(struct kunit *test) { mempool_t pool; size_t size = KMALLOC_MAX_CACHE_SIZE + 1; void *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_oob_right_helper(test, &pool, size); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_slab_oob_right(struct kunit *test) { mempool_t pool; size_t size = 123; struct kmem_cache *cache; cache = mempool_prepare_slab(test, &pool, size); mempool_oob_right_helper(test, &pool, size); mempool_exit(&pool); kmem_cache_destroy(cache); } /* * Skip the out-of-bounds test for page mempool. With Generic KASAN, page * allocations have no redzones, and thus the out-of-bounds detection is not * guaranteed; see https://bugzilla.kernel.org/show_bug.cgi?id=210503. With * the tag-based KASAN modes, the neighboring allocation might have the same * tag; see https://bugzilla.kernel.org/show_bug.cgi?id=203505. */ static void mempool_uaf_helper(struct kunit *test, mempool_t *pool, bool page) { char *elem, *ptr; elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); mempool_free(elem, pool); ptr = page ? page_address((struct page *)elem) : elem; KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]); } static void mempool_kmalloc_uaf(struct kunit *test) { mempool_t pool; size_t size = 128; void *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_uaf_helper(test, &pool, false); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_kmalloc_large_uaf(struct kunit *test) { mempool_t pool; size_t size = KMALLOC_MAX_CACHE_SIZE + 1; void *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_uaf_helper(test, &pool, false); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_slab_uaf(struct kunit *test) { mempool_t pool; size_t size = 123; struct kmem_cache *cache; cache = mempool_prepare_slab(test, &pool, size); mempool_uaf_helper(test, &pool, false); mempool_exit(&pool); kmem_cache_destroy(cache); } static void mempool_page_alloc_uaf(struct kunit *test) { mempool_t pool; int order = 2; void *extra_elem; extra_elem = mempool_prepare_page(test, &pool, order); mempool_uaf_helper(test, &pool, true); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_double_free_helper(struct kunit *test, mempool_t *pool) { char *elem; elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); mempool_free(elem, pool); KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem, pool)); } static void mempool_kmalloc_double_free(struct kunit *test) { mempool_t pool; size_t size = 128; char *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_double_free_helper(test, &pool); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_kmalloc_large_double_free(struct kunit *test) { mempool_t pool; size_t size = KMALLOC_MAX_CACHE_SIZE + 1; char *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_double_free_helper(test, &pool); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_page_alloc_double_free(struct kunit *test) { mempool_t pool; int order = 2; char *extra_elem; extra_elem = mempool_prepare_page(test, &pool, order); mempool_double_free_helper(test, &pool); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_kmalloc_invalid_free_helper(struct kunit *test, mempool_t *pool) { char *elem; elem = mempool_alloc_preallocated(pool); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem); KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem + 1, pool)); mempool_free(elem, pool); } static void mempool_kmalloc_invalid_free(struct kunit *test) { mempool_t pool; size_t size = 128; char *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_kmalloc_invalid_free_helper(test, &pool); mempool_free(extra_elem, &pool); mempool_exit(&pool); } static void mempool_kmalloc_large_invalid_free(struct kunit *test) { mempool_t pool; size_t size = KMALLOC_MAX_CACHE_SIZE + 1; char *extra_elem; extra_elem = mempool_prepare_kmalloc(test, &pool, size); mempool_kmalloc_invalid_free_helper(test, &pool); mempool_free(extra_elem, &pool); mempool_exit(&pool); } /* * Skip the invalid-free test for page mempool. The invalid-free detection only * works for compound pages and mempool preallocates all page elements without * the __GFP_COMP flag. */ static char global_array[10]; static void kasan_global_oob_right(struct kunit *test) { /* * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS * from failing here and panicking the kernel, access the array via a * volatile pointer, which will prevent the compiler from being able to * determine the array bounds. * * This access uses a volatile pointer to char (char *volatile) rather * than the more conventional pointer to volatile char (volatile char *) * because we want to prevent the compiler from making inferences about * the pointer itself (i.e. its array bounds), not the data that it * refers to. */ char *volatile array = global_array; char *p = &array[ARRAY_SIZE(global_array) + 3]; /* Only generic mode instruments globals. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void kasan_global_oob_left(struct kunit *test) { char *volatile array = global_array; char *p = array - 3; /* * GCC is known to fail this test, skip it. * See https://bugzilla.kernel.org/show_bug.cgi?id=215051. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG); KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void kasan_stack_oob(struct kunit *test) { char stack_array[10]; /* See comment in kasan_global_oob_right. */ char *volatile array = stack_array; char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF]; KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void kasan_alloca_oob_left(struct kunit *test) { volatile int i = 10; char alloca_array[i]; /* See comment in kasan_global_oob_right. */ char *volatile array = alloca_array; char *p = array - 1; /* Only generic mode instruments dynamic allocas. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void kasan_alloca_oob_right(struct kunit *test) { volatile int i = 10; char alloca_array[i]; /* See comment in kasan_global_oob_right. */ char *volatile array = alloca_array; char *p = array + i; /* Only generic mode instruments dynamic allocas. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK); KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void kasan_memchr(struct kunit *test) { char *ptr; size_t size = 24; /* * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT); if (OOB_TAG_OFF) size = round_up(size, OOB_TAG_OFF); ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = memchr(ptr, '1', size + 1)); kfree(ptr); } static void kasan_memcmp(struct kunit *test) { char *ptr; size_t size = 24; int arr[9]; /* * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT); if (OOB_TAG_OFF) size = round_up(size, OOB_TAG_OFF); ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset(arr, 0, sizeof(arr)); OPTIMIZER_HIDE_VAR(ptr); OPTIMIZER_HIDE_VAR(size); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = memcmp(ptr, arr, size+1)); kfree(ptr); } static void kasan_strings(struct kunit *test) { char *ptr; size_t size = 24; /* * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT. * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT); ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); /* * Try to cause only 1 invalid access (less spam in dmesg). * For that we need ptr to point to zeroed byte. * Skip metadata that could be stored in freed object so ptr * will likely point to zeroed byte. */ ptr += 16; KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strchr(ptr, '1')); KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strrchr(ptr, '1')); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strcmp(ptr, "2")); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strncmp(ptr, "2", 1)); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strlen(ptr)); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strnlen(ptr, 1)); } static void kasan_bitops_modify(struct kunit *test, int nr, void *addr) { KUNIT_EXPECT_KASAN_FAIL(test, set_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, change_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(nr, addr)); } static void kasan_bitops_test_and_modify(struct kunit *test, int nr, void *addr) { KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(nr, addr)); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = test_bit(nr, addr)); if (nr < 7) KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = xor_unlock_is_negative_byte(1 << nr, addr)); } static void kasan_bitops_generic(struct kunit *test) { long *bits; /* This test is specifically crafted for the generic mode. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC); /* * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes; * this way we do not actually corrupt other memory. */ bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits); /* * Below calls try to access bit within allocated memory; however, the * below accesses are still out-of-bounds, since bitops are defined to * operate on the whole long the bit is in. */ kasan_bitops_modify(test, BITS_PER_LONG, bits); /* * Below calls try to access bit beyond allocated memory. */ kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, bits); kfree(bits); } static void kasan_bitops_tags(struct kunit *test) { long *bits; /* This test is specifically crafted for tag-based modes. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */ bits = kzalloc(48, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits); /* Do the accesses past the 48 allocated bytes, but within the redone. */ kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48); kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48); kfree(bits); } static void vmalloc_helpers_tags(struct kunit *test) { void *ptr; /* This test is intended for tag-based modes. */ KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC); if (!kasan_vmalloc_enabled()) kunit_skip(test, "Test requires kasan.vmalloc=on"); ptr = vmalloc(PAGE_SIZE); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); /* Check that the returned pointer is tagged. */ KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); /* Make sure exported vmalloc helpers handle tagged pointers. */ KUNIT_ASSERT_TRUE(test, is_vmalloc_addr(ptr)); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vmalloc_to_page(ptr)); #if !IS_MODULE(CONFIG_KASAN_KUNIT_TEST) { int rv; /* Make sure vmalloc'ed memory permissions can be changed. */ rv = set_memory_ro((unsigned long)ptr, 1); KUNIT_ASSERT_GE(test, rv, 0); rv = set_memory_rw((unsigned long)ptr, 1); KUNIT_ASSERT_GE(test, rv, 0); } #endif vfree(ptr); } static void vmalloc_oob(struct kunit *test) { char *v_ptr, *p_ptr; struct page *page; size_t size = PAGE_SIZE / 2 - KASAN_GRANULE_SIZE - 5; KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC); if (!kasan_vmalloc_enabled()) kunit_skip(test, "Test requires kasan.vmalloc=on"); v_ptr = vmalloc(size); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr); OPTIMIZER_HIDE_VAR(v_ptr); /* * We have to be careful not to hit the guard page in vmalloc tests. * The MMU will catch that and crash us. */ /* Make sure in-bounds accesses are valid. */ v_ptr[0] = 0; v_ptr[size - 1] = 0; /* * An unaligned access past the requested vmalloc size. * Only generic KASAN can precisely detect these. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size]); /* An aligned access into the first out-of-bounds granule. */ KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size + 5]); /* Check that in-bounds accesses to the physical page are valid. */ page = vmalloc_to_page(v_ptr); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page); p_ptr = page_address(page); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr); p_ptr[0] = 0; vfree(v_ptr); /* * We can't check for use-after-unmap bugs in this nor in the following * vmalloc tests, as the page might be fully unmapped and accessing it * will crash the kernel. */ } static void vmap_tags(struct kunit *test) { char *p_ptr, *v_ptr; struct page *p_page, *v_page; /* * This test is specifically crafted for the software tag-based mode, * the only tag-based mode that poisons vmap mappings. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS); KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC); if (!kasan_vmalloc_enabled()) kunit_skip(test, "Test requires kasan.vmalloc=on"); p_page = alloc_pages(GFP_KERNEL, 1); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page); p_ptr = page_address(p_page); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr); v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr); /* * We can't check for out-of-bounds bugs in this nor in the following * vmalloc tests, as allocations have page granularity and accessing * the guard page will crash the kernel. */ KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL); /* Make sure that in-bounds accesses through both pointers work. */ *p_ptr = 0; *v_ptr = 0; /* Make sure vmalloc_to_page() correctly recovers the page pointer. */ v_page = vmalloc_to_page(v_ptr); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_page); KUNIT_EXPECT_PTR_EQ(test, p_page, v_page); vunmap(v_ptr); free_pages((unsigned long)p_ptr, 1); } static void vm_map_ram_tags(struct kunit *test) { char *p_ptr, *v_ptr; struct page *page; /* * This test is specifically crafted for the software tag-based mode, * the only tag-based mode that poisons vm_map_ram mappings. */ KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS); page = alloc_pages(GFP_KERNEL, 1); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page); p_ptr = page_address(page); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr); v_ptr = vm_map_ram(&page, 1, -1); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr); KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL); /* Make sure that in-bounds accesses through both pointers work. */ *p_ptr = 0; *v_ptr = 0; vm_unmap_ram(v_ptr, 1); free_pages((unsigned long)p_ptr, 1); } /* * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN, * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based * modes. */ static void match_all_not_assigned(struct kunit *test) { char *ptr; struct page *pages; int i, size, order; KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); for (i = 0; i < 256; i++) { size = get_random_u32_inclusive(1, 1024); ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); kfree(ptr); } for (i = 0; i < 256; i++) { order = get_random_u32_inclusive(1, 4); pages = alloc_pages(GFP_KERNEL, order); ptr = page_address(pages); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); free_pages((unsigned long)ptr, order); } if (!kasan_vmalloc_enabled()) return; for (i = 0; i < 256; i++) { size = get_random_u32_inclusive(1, 1024); ptr = vmalloc(size); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN); KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); vfree(ptr); } } /* Check that 0xff works as a match-all pointer tag for tag-based modes. */ static void match_all_ptr_tag(struct kunit *test) { char *ptr; u8 tag; KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); ptr = kmalloc(128, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); /* Backup the assigned tag. */ tag = get_tag(ptr); KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL); /* Reset the tag to 0xff.*/ ptr = set_tag(ptr, KASAN_TAG_KERNEL); /* This access shouldn't trigger a KASAN report. */ *ptr = 0; /* Recover the pointer tag and free. */ ptr = set_tag(ptr, tag); kfree(ptr); } /* Check that there are no match-all memory tags for tag-based modes. */ static void match_all_mem_tag(struct kunit *test) { char *ptr; int tag; KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); ptr = kmalloc(128, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL); /* For each possible tag value not matching the pointer tag. */ for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) { /* * For Software Tag-Based KASAN, skip the majority of tag * values to avoid the test printing too many reports. */ if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) && tag >= KASAN_TAG_MIN + 8 && tag <= KASAN_TAG_KERNEL - 8) continue; if (tag == get_tag(ptr)) continue; /* Mark the first memory granule with the chosen memory tag. */ kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false); /* This access must cause a KASAN report. */ KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0); } /* Recover the memory tag and free. */ kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false); kfree(ptr); } /* * Check that Rust performing a use-after-free using `unsafe` is detected. * This is a smoke test to make sure that Rust is being sanitized properly. */ static void rust_uaf(struct kunit *test) { KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_RUST); KUNIT_EXPECT_KASAN_FAIL(test, kasan_test_rust_uaf()); } static struct kunit_case kasan_kunit_test_cases[] = { KUNIT_CASE(kmalloc_oob_right), KUNIT_CASE(kmalloc_oob_left), KUNIT_CASE(kmalloc_node_oob_right), KUNIT_CASE(kmalloc_big_oob_right), KUNIT_CASE(kmalloc_large_oob_right), KUNIT_CASE(kmalloc_large_uaf), KUNIT_CASE(kmalloc_large_invalid_free), KUNIT_CASE(page_alloc_oob_right), KUNIT_CASE(page_alloc_uaf), KUNIT_CASE(krealloc_more_oob), KUNIT_CASE(krealloc_less_oob), KUNIT_CASE(krealloc_large_more_oob), KUNIT_CASE(krealloc_large_less_oob), KUNIT_CASE(krealloc_uaf), KUNIT_CASE(kmalloc_oob_16), KUNIT_CASE(kmalloc_uaf_16), KUNIT_CASE(kmalloc_oob_in_memset), KUNIT_CASE(kmalloc_oob_memset_2), KUNIT_CASE(kmalloc_oob_memset_4), KUNIT_CASE(kmalloc_oob_memset_8), KUNIT_CASE(kmalloc_oob_memset_16), KUNIT_CASE(kmalloc_memmove_negative_size), KUNIT_CASE(kmalloc_memmove_invalid_size), KUNIT_CASE(kmalloc_uaf), KUNIT_CASE(kmalloc_uaf_memset), KUNIT_CASE(kmalloc_uaf2), KUNIT_CASE(kmalloc_uaf3), KUNIT_CASE(kmalloc_double_kzfree), KUNIT_CASE(ksize_unpoisons_memory), KUNIT_CASE(ksize_uaf), KUNIT_CASE(rcu_uaf), KUNIT_CASE(workqueue_uaf), KUNIT_CASE(kfree_via_page), KUNIT_CASE(kfree_via_phys), KUNIT_CASE(kmem_cache_oob), KUNIT_CASE(kmem_cache_double_free), KUNIT_CASE(kmem_cache_invalid_free), KUNIT_CASE(kmem_cache_rcu_uaf), KUNIT_CASE(kmem_cache_double_destroy), KUNIT_CASE(kmem_cache_accounted), KUNIT_CASE(kmem_cache_bulk), KUNIT_CASE(mempool_kmalloc_oob_right), KUNIT_CASE(mempool_kmalloc_large_oob_right), KUNIT_CASE(mempool_slab_oob_right), KUNIT_CASE(mempool_kmalloc_uaf), KUNIT_CASE(mempool_kmalloc_large_uaf), KUNIT_CASE(mempool_slab_uaf), KUNIT_CASE(mempool_page_alloc_uaf), KUNIT_CASE(mempool_kmalloc_double_free), KUNIT_CASE(mempool_kmalloc_large_double_free), KUNIT_CASE(mempool_page_alloc_double_free), KUNIT_CASE(mempool_kmalloc_invalid_free), KUNIT_CASE(mempool_kmalloc_large_invalid_free), KUNIT_CASE(kasan_global_oob_right), KUNIT_CASE(kasan_global_oob_left), KUNIT_CASE(kasan_stack_oob), KUNIT_CASE(kasan_alloca_oob_left), KUNIT_CASE(kasan_alloca_oob_right), KUNIT_CASE(kasan_memchr), KUNIT_CASE(kasan_memcmp), KUNIT_CASE(kasan_strings), KUNIT_CASE(kasan_bitops_generic), KUNIT_CASE(kasan_bitops_tags), KUNIT_CASE(kasan_atomics), KUNIT_CASE(vmalloc_helpers_tags), KUNIT_CASE(vmalloc_oob), KUNIT_CASE(vmap_tags), KUNIT_CASE(vm_map_ram_tags), KUNIT_CASE(match_all_not_assigned), KUNIT_CASE(match_all_ptr_tag), KUNIT_CASE(match_all_mem_tag), KUNIT_CASE(rust_uaf), {} }; static struct kunit_suite kasan_kunit_test_suite = { .name = "kasan", .test_cases = kasan_kunit_test_cases, .exit = kasan_test_exit, .suite_init = kasan_suite_init, .suite_exit = kasan_suite_exit, }; kunit_test_suite(kasan_kunit_test_suite); MODULE_LICENSE("GPL");