// SPDX-License-Identifier: GPL-2.0-only /* * * Copyright (c) 2014 Samsung Electronics Co., Ltd. * Author: Andrey Ryabinin */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../mm/kasan/kasan.h" #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE) /* * We assign some test results to these globals to make sure the tests * are not eliminated as dead code. */ void *kasan_ptr_result; int kasan_int_result; static struct kunit_resource resource; static struct kunit_kasan_expectation fail_data; static bool multishot; static int kasan_test_init(struct kunit *test) { /* * Temporarily enable multi-shot mode and set panic_on_warn=0. * Otherwise, we'd only get a report for the first case. */ multishot = kasan_save_enable_multi_shot(); return 0; } static void kasan_test_exit(struct kunit *test) { kasan_restore_multi_shot(multishot); } /** * KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does * not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do * Do not use this name for a KUnit resource outside here. * */ #define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \ fail_data.report_expected = true; \ fail_data.report_found = false; \ kunit_add_named_resource(test, \ NULL, \ NULL, \ &resource, \ "kasan_data", &fail_data); \ condition; \ KUNIT_EXPECT_EQ(test, \ fail_data.report_expected, \ fail_data.report_found); \ } while (0) static void kmalloc_oob_right(struct kunit *test) { char *ptr; size_t size = 123; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 'x'); 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); 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); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0); kfree(ptr); } static void kmalloc_pagealloc_oob_right(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; if (!IS_ENABLED(CONFIG_SLUB)) { kunit_info(test, "CONFIG_SLUB is not enabled."); return; } /* Allocate a chunk that does not fit into a SLUB cache to trigger * the page allocator fallback. */ ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0); kfree(ptr); } static void kmalloc_pagealloc_uaf(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; if (!IS_ENABLED(CONFIG_SLUB)) { kunit_info(test, "CONFIG_SLUB is not enabled."); return; } ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); kfree(ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0); } static void kmalloc_pagealloc_invalid_free(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE + 10; if (!IS_ENABLED(CONFIG_SLUB)) { kunit_info(test, "CONFIG_SLUB is not enabled."); return; } ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1)); } static void kmalloc_large_oob_right(struct kunit *test) { char *ptr; size_t size = KMALLOC_MAX_CACHE_SIZE - 256; /* Allocate a chunk that is large enough, but still fits into a slab * and does not trigger the page allocator fallback in SLUB. */ ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0); kfree(ptr); } static void kmalloc_oob_krealloc_more(struct kunit *test) { char *ptr1, *ptr2; size_t size1 = 17; size_t size2 = 19; 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); KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x'); kfree(ptr2); } static void kmalloc_oob_krealloc_less(struct kunit *test) { char *ptr1, *ptr2; size_t size1 = 17; size_t size2 = 15; 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); KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x'); kfree(ptr2); } static void kmalloc_oob_16(struct kunit *test) { struct { u64 words[2]; } *ptr1, *ptr2; ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1); ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2); KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2); kfree(ptr1); kfree(ptr2); } static void kmalloc_oob_memset_2(struct kunit *test) { char *ptr; size_t size = 8; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2)); kfree(ptr); } static void kmalloc_oob_memset_4(struct kunit *test) { char *ptr; size_t size = 8; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 5 + OOB_TAG_OFF, 0, 4)); kfree(ptr); } static void kmalloc_oob_memset_8(struct kunit *test) { char *ptr; size_t size = 8; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 8)); kfree(ptr); } static void kmalloc_oob_memset_16(struct kunit *test) { char *ptr; size_t size = 16; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 16)); kfree(ptr); } static void kmalloc_oob_in_memset(struct kunit *test) { char *ptr; size_t size = 666; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + 5 + OOB_TAG_OFF)); kfree(ptr); } static void kmalloc_memmove_invalid_size(struct kunit *test) { char *ptr; size_t size = 64; volatile size_t invalid_size = -2; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset((char *)ptr, 0, 64); 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, *(ptr + 8) = 'x'); } static void kmalloc_uaf_memset(struct kunit *test) { char *ptr; size_t size = 33; 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; 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); KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x'); KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2); kfree(ptr2); } 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 = 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 memcg_accounted_kmem_cache(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 char global_array[10]; static void kasan_global_oob(struct kunit *test) { volatile int i = 3; char *p = &global_array[ARRAY_SIZE(global_array) + i]; KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } static void ksize_unpoisons_memory(struct kunit *test) { char *ptr; size_t size = 123, real_size; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); real_size = ksize(ptr); /* This access doesn't trigger an error. */ ptr[size] = 'x'; /* This one does. */ KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y'); kfree(ptr); } static void kasan_stack_oob(struct kunit *test) { char stack_array[10]; volatile int i = OOB_TAG_OFF; char *p = &stack_array[ARRAY_SIZE(stack_array) + i]; if (!IS_ENABLED(CONFIG_KASAN_STACK)) { kunit_info(test, "CONFIG_KASAN_STACK is not enabled"); return; } 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]; char *p = alloca_array - 1; if (!IS_ENABLED(CONFIG_KASAN_STACK)) { kunit_info(test, "CONFIG_KASAN_STACK is not enabled"); return; } 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]; char *p = alloca_array + i; if (!IS_ENABLED(CONFIG_KASAN_STACK)) { kunit_info(test, "CONFIG_KASAN_STACK is not enabled"); return; } KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p); } 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 kasan_memchr(struct kunit *test) { char *ptr; size_t size = 24; /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); return; } ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); 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]; /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); return; } ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); memset(arr, 0, sizeof(arr)); 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; /* See https://bugzilla.kernel.org/show_bug.cgi?id=206337 */ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) { kunit_info(test, "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT"); return; } 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(struct kunit *test) { /* * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes; * this way we do not actually corrupt other memory. */ long *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. */ KUNIT_EXPECT_KASAN_FAIL(test, set_bit(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, change_bit(BITS_PER_LONG, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(BITS_PER_LONG, bits)); /* * Below calls try to access bit beyond allocated memory. */ KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits)); #if defined(clear_bit_unlock_is_negative_byte) KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = clear_bit_unlock_is_negative_byte( BITS_PER_LONG + BITS_PER_BYTE, bits)); #endif kfree(bits); } 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)); } static void vmalloc_oob(struct kunit *test) { void *area; if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) { kunit_info(test, "CONFIG_KASAN_VMALLOC is not enabled."); return; } /* * We have to be careful not to hit the guard page. * The MMU will catch that and crash us. */ area = vmalloc(3000); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, area); KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)area)[3100]); vfree(area); } 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_pagealloc_oob_right), KUNIT_CASE(kmalloc_pagealloc_uaf), KUNIT_CASE(kmalloc_pagealloc_invalid_free), KUNIT_CASE(kmalloc_large_oob_right), KUNIT_CASE(kmalloc_oob_krealloc_more), KUNIT_CASE(kmalloc_oob_krealloc_less), KUNIT_CASE(kmalloc_oob_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_invalid_size), KUNIT_CASE(kmalloc_uaf), KUNIT_CASE(kmalloc_uaf_memset), KUNIT_CASE(kmalloc_uaf2), KUNIT_CASE(kfree_via_page), KUNIT_CASE(kfree_via_phys), KUNIT_CASE(kmem_cache_oob), KUNIT_CASE(memcg_accounted_kmem_cache), KUNIT_CASE(kasan_global_oob), KUNIT_CASE(kasan_stack_oob), KUNIT_CASE(kasan_alloca_oob_left), KUNIT_CASE(kasan_alloca_oob_right), KUNIT_CASE(ksize_unpoisons_memory), KUNIT_CASE(kmem_cache_double_free), KUNIT_CASE(kmem_cache_invalid_free), KUNIT_CASE(kasan_memchr), KUNIT_CASE(kasan_memcmp), KUNIT_CASE(kasan_strings), KUNIT_CASE(kasan_bitops), KUNIT_CASE(kmalloc_double_kzfree), KUNIT_CASE(vmalloc_oob), {} }; static struct kunit_suite kasan_kunit_test_suite = { .name = "kasan", .init = kasan_test_init, .test_cases = kasan_kunit_test_cases, .exit = kasan_test_exit, }; kunit_test_suite(kasan_kunit_test_suite); MODULE_LICENSE("GPL");