From a2f11547052001bd448ccec81dd1e68409078fbb Mon Sep 17 00:00:00 2001 From: Matthew Maurer Date: Tue, 20 Aug 2024 19:48:59 +0000 Subject: kasan: rust: Add KASAN smoke test via UAF Adds a smoke test to ensure that KASAN in Rust is actually detecting a Rust-native UAF. There is significant room to expand this test suite, but this will at least ensure that flags are having the intended effect. The rename from kasan_test.c to kasan_test_c.c is in order to allow the single kasan_test.ko test suite to contain both a .o file produced by the C compiler and one produced by rustc. Signed-off-by: Matthew Maurer Reviewed-by: Andrey Konovalov Link: https://lore.kernel.org/r/20240820194910.187826-5-mmaurer@google.com [ Applied empty line nit, removed double empty line, applied `rustfmt` and formatted crate comment. - Miguel ] Signed-off-by: Miguel Ojeda --- mm/kasan/Makefile | 8 +- mm/kasan/kasan.h | 6 + mm/kasan/kasan_test.c | 1987 ------------------------------------------ mm/kasan/kasan_test_c.c | 1998 +++++++++++++++++++++++++++++++++++++++++++ mm/kasan/kasan_test_rust.rs | 21 + 5 files changed, 2032 insertions(+), 1988 deletions(-) delete mode 100644 mm/kasan/kasan_test.c create mode 100644 mm/kasan/kasan_test_c.c create mode 100644 mm/kasan/kasan_test_rust.rs diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index 7634dd2a6128..b88543e5c0cc 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -44,7 +44,8 @@ ifndef CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX CFLAGS_KASAN_TEST += -fno-builtin endif -CFLAGS_kasan_test.o := $(CFLAGS_KASAN_TEST) +CFLAGS_kasan_test_c.o := $(CFLAGS_KASAN_TEST) +RUSTFLAGS_kasan_test_rust.o := $(RUSTFLAGS_KASAN) CFLAGS_kasan_test_module.o := $(CFLAGS_KASAN_TEST) obj-y := common.o report.o @@ -52,5 +53,10 @@ obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quaran obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o tags.o report_tags.o obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o tags.o report_tags.o +kasan_test-objs := kasan_test_c.o +ifdef CONFIG_RUST + kasan_test-objs += kasan_test_rust.o +endif + obj-$(CONFIG_KASAN_KUNIT_TEST) += kasan_test.o obj-$(CONFIG_KASAN_MODULE_TEST) += kasan_test_module.o diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index fb2b9ac0659a..f438a6cdc964 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -555,6 +555,12 @@ static inline bool kasan_arch_is_ready(void) { return true; } void kasan_kunit_test_suite_start(void); void kasan_kunit_test_suite_end(void); +#ifdef CONFIG_RUST +char kasan_test_rust_uaf(void); +#else +static inline char kasan_test_rust_uaf(void) { return '\0'; } +#endif + #else /* CONFIG_KASAN_KUNIT_TEST */ static inline void kasan_kunit_test_suite_start(void) { } diff --git a/mm/kasan/kasan_test.c b/mm/kasan/kasan_test.c deleted file mode 100644 index 7b32be2a3cf0..000000000000 --- a/mm/kasan/kasan_test.c +++ /dev/null @@ -1,1987 +0,0 @@ -// 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 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); -} - -static void vmalloc_percpu(struct kunit *test) -{ - char __percpu *ptr; - int cpu; - - /* - * This test is specifically crafted for the software tag-based mode, - * the only tag-based mode that poisons percpu mappings. - */ - KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS); - - ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE); - - for_each_possible_cpu(cpu) { - char *c_ptr = per_cpu_ptr(ptr, cpu); - - KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN); - KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL); - - /* Make sure that in-bounds accesses don't crash the kernel. */ - *c_ptr = 0; - } - - free_percpu(ptr); -} - -/* - * 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); -} - -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_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(vmalloc_percpu), - KUNIT_CASE(match_all_not_assigned), - KUNIT_CASE(match_all_ptr_tag), - KUNIT_CASE(match_all_mem_tag), - {} -}; - -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"); diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c new file mode 100644 index 000000000000..0fd445a3be1c --- /dev/null +++ b/mm/kasan/kasan_test_c.c @@ -0,0 +1,1998 @@ +// 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 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); +} + +static void vmalloc_percpu(struct kunit *test) +{ + char __percpu *ptr; + int cpu; + + /* + * This test is specifically crafted for the software tag-based mode, + * the only tag-based mode that poisons percpu mappings. + */ + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS); + + ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE); + + for_each_possible_cpu(cpu) { + char *c_ptr = per_cpu_ptr(ptr, cpu); + + KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN); + KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL); + + /* Make sure that in-bounds accesses don't crash the kernel. */ + *c_ptr = 0; + } + + free_percpu(ptr); +} + +/* + * 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_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(vmalloc_percpu), + 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"); diff --git a/mm/kasan/kasan_test_rust.rs b/mm/kasan/kasan_test_rust.rs new file mode 100644 index 000000000000..caa7175964ef --- /dev/null +++ b/mm/kasan/kasan_test_rust.rs @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Helper crate for KASAN testing. +//! +//! Provides behavior to check the sanitization of Rust code. + +use core::ptr::addr_of_mut; +use kernel::prelude::*; + +/// Trivial UAF - allocate a big vector, grab a pointer partway through, +/// drop the vector, and touch it. +#[no_mangle] +pub extern "C" fn kasan_test_rust_uaf() -> u8 { + let mut v: Vec = Vec::new(); + for _ in 0..4096 { + v.push(0x42, GFP_KERNEL).unwrap(); + } + let ptr: *mut u8 = addr_of_mut!(v[2048]); + drop(v); + unsafe { *ptr } +} -- cgit v1.2.3-70-g09d2