This patchset contains everything needed to integrate KASAN and KUnit.
KUnit will be able to: (1) Fail tests when an unexpected KASAN error occurs (2) Pass tests when an expected KASAN error occurs
Convert KASAN tests to KUnit with the exception of copy_user_test because KUnit is unable to test those.
Add documentation on how to run the KASAN tests with KUnit and what to expect when running these tests.
This patchset depends on: - "kunit: extend kunit resources API" [1] - This is already present in the kselftest/kunit branch
I'd _really_ like to get this into 5.9 if possible: we also have some other changes which depend on some things here.
Changes from v8: - Rebased on top of kselftest/kunit - (Which, with this patchset, should rebase cleanly on 5.8-rc7) - Renamed the KUnit test suite, config name to patch the proposed naming guidelines for KUnit tests[6]
Changes from v7: - Rebased on top of kselftest/kunit - Rebased on top of v4 of the kunit resources API[1] - Rebased on top of v4 of the FORTIFY_SOURCE fix[2,3,4] - Updated the Kconfig entry to support KUNIT_ALL_TESTS
Changes from v6: - Rebased on top of kselftest/kunit - Rebased on top of Daniel Axtens' fix for FORTIFY_SOURCE incompatibilites [2] - Removed a redundant report_enabled() check. - Fixed some places with out of date Kconfig names in the documentation.
Changes from v5: - Split out the panic_on_warn changes to a separate patch. - Fix documentation to fewer to the new Kconfig names. - Fix some changes which were in the wrong patch. - Rebase on top of kselftest/kunit (currently identical to 5.7-rc1)
Changes from v4: - KASAN no longer will panic on errors if both panic_on_warn and kasan_multishot are enabled. - As a result, the KASAN tests will no-longer disable panic_on_warn. - This also means panic_on_warn no-longer needs to be exported. - The use of temporary "kasan_data" variables has been cleaned up somewhat. - A potential refcount/resource leak should multiple KASAN errors appear during an assertion was fixed. - Some wording changes to the KASAN test Kconfig entries.
Changes from v3: - KUNIT_SET_KASAN_DATA and KUNIT_DO_EXPECT_KASAN_FAIL have been combined and included in KUNIT_DO_EXPECT_KASAN_FAIL() instead. - Reordered logic in kasan_update_kunit_status() in report.c to be easier to read. - Added comment to not use the name "kasan_data" for any kunit tests outside of KUNIT_EXPECT_KASAN_FAIL().
Changes since v2: - Due to Alan's changes in [1], KUnit can be built as a module. - The name of the tests that could not be run with KUnit has been changed to be more generic: test_kasan_module. - Documentation on how to run the new KASAN tests and what to expect when running them has been added. - Some variables and functions are now static. - Now save/restore panic_on_warn in a similar way to kasan_multi_shot and renamed the init/exit functions to be more generic to accommodate. - Due to [4] in kasan_strings, kasan_memchr, and kasan_memcmp will fail if CONFIG_AMD_MEM_ENCRYPT is enabled so return early and print message explaining this circumstance. - Changed preprocessor checks to C checks where applicable.
Changes since v1: - Make use of Alan Maguire's suggestion to use his patch that allows static resources for integration instead of adding a new attribute to the kunit struct - All KUNIT_EXPECT_KASAN_FAIL statements are local to each test - The definition of KUNIT_EXPECT_KASAN_FAIL is local to the test_kasan.c file since it seems this is the only place this will be used. - Integration relies on KUnit being builtin - copy_user_test has been separated into its own file since KUnit is unable to test these. This can be run as a module just as before, using CONFIG_TEST_KASAN_USER - The addition to the current task has been separated into its own patch as this is a significant enough change to be on its own.
[1] https://lore.kernel.org/linux-kselftest/CAFd5g46Uu_5TG89uOm0Dj5CMq+11cwjBnsd... [2] https://lore.kernel.org/linux-mm/20200424145521.8203-1-dja@axtens.net/ [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... [4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... [5] https://bugzilla.kernel.org/show_bug.cgi?id=206337 [6] https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@goo...
David Gow (1): mm: kasan: Do not panic if both panic_on_warn and kasan_multishot set
Patricia Alfonso (4): Add KUnit Struct to Current Task KUnit: KASAN Integration KASAN: Port KASAN Tests to KUnit KASAN: Testing Documentation
Documentation/dev-tools/kasan.rst | 70 +++ include/kunit/test.h | 5 + include/linux/kasan.h | 6 + include/linux/sched.h | 4 + lib/Kconfig.kasan | 22 +- lib/Makefile | 7 +- lib/kunit/test.c | 13 +- lib/test_kasan.c | 858 ------------------------------ mm/kasan/report.c | 34 +- 9 files changed, 147 insertions(+), 872 deletions(-) delete mode 100644 lib/test_kasan.c
From: Patricia Alfonso trishalfonso@google.com
In order to integrate debugging tools like KASAN into the KUnit framework, add KUnit struct to the current task to keep track of the current KUnit test.
Signed-off-by: Patricia Alfonso trishalfonso@google.com Reviewed-by: Brendan Higgins brendanhiggins@google.com Signed-off-by: David Gow davidgow@google.com --- include/linux/sched.h | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h index 683372943093..3a27399c98b1 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1197,6 +1197,10 @@ struct task_struct { struct kcsan_ctx kcsan_ctx; #endif
+#if IS_ENABLED(CONFIG_KUNIT) + struct kunit *kunit_test; +#endif + #ifdef CONFIG_FUNCTION_GRAPH_TRACER /* Index of current stored address in ret_stack: */ int curr_ret_stack;
From: Patricia Alfonso trishalfonso@google.com
Integrate KASAN into KUnit testing framework. - Fail tests when KASAN reports an error that is not expected - Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN tests - Expected KASAN reports pass tests and are still printed when run without kunit_tool (kunit_tool still bypasses the report due to the test passing) - KUnit struct in current task used to keep track of the current test from KASAN code
Make use of "[PATCH v3 kunit-next 1/2] kunit: generalize kunit_resource API beyond allocated resources" and "[PATCH v3 kunit-next 2/2] kunit: add support for named resources" from Alan Maguire [1] - A named resource is added to a test when a KASAN report is expected - This resource contains a struct for kasan_data containing booleans representing if a KASAN report is expected and if a KASAN report is found
[1] (https://lore.kernel.org/linux-kselftest/1583251361-12748-1-git-send-email-al...)
Signed-off-by: Patricia Alfonso trishalfonso@google.com Signed-off-by: David Gow davidgow@google.com Reviewed-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com Acked-by: Brendan Higgins brendanhiggins@google.com --- include/kunit/test.h | 5 +++++ include/linux/kasan.h | 6 ++++++ lib/kunit/test.c | 13 +++++++----- lib/test_kasan.c | 47 +++++++++++++++++++++++++++++++++++++++++-- mm/kasan/report.c | 32 +++++++++++++++++++++++++++++ 5 files changed, 96 insertions(+), 7 deletions(-)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 59f3144f009a..3391f38389f8 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -224,6 +224,11 @@ struct kunit { struct list_head resources; /* Protected by lock. */ };
+static inline void kunit_set_failure(struct kunit *test) +{ + WRITE_ONCE(test->success, false); +} + void kunit_init_test(struct kunit *test, const char *name, char *log);
int kunit_run_tests(struct kunit_suite *suite); diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 82522e996c76..3ccb7874a466 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -14,6 +14,12 @@ struct task_struct; #include <linux/pgtable.h> #include <asm/kasan.h>
+/* kasan_data struct is used in KUnit tests for KASAN expected failures */ +struct kunit_kasan_expectation { + bool report_expected; + bool report_found; +}; + extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE]; extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD]; diff --git a/lib/kunit/test.c b/lib/kunit/test.c index c36037200310..dcc35fd30d95 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -10,16 +10,12 @@ #include <linux/kernel.h> #include <linux/kref.h> #include <linux/sched/debug.h> +#include <linux/sched.h>
#include "debugfs.h" #include "string-stream.h" #include "try-catch-impl.h"
-static void kunit_set_failure(struct kunit *test) -{ - WRITE_ONCE(test->success, false); -} - static void kunit_print_tap_version(void) { static bool kunit_has_printed_tap_version; @@ -288,6 +284,10 @@ static void kunit_try_run_case(void *data) struct kunit_suite *suite = ctx->suite; struct kunit_case *test_case = ctx->test_case;
+#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)) + current->kunit_test = test; +#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT) */ + /* * kunit_run_case_internal may encounter a fatal error; if it does, * abort will be called, this thread will exit, and finally the parent @@ -602,6 +602,9 @@ void kunit_cleanup(struct kunit *test) spin_unlock(&test->lock); kunit_remove_resource(test, res); } +#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)) + current->kunit_test = NULL; +#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)*/ } EXPORT_SYMBOL_GPL(kunit_cleanup);
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index dc2c6a51d11a..842adcd30943 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -23,19 +23,62 @@
#include <asm/page.h>
+#include <kunit/test.h> + /* * We assign some test results to these globals to make sure the tests * are not eliminated as dead code. */
-int kasan_int_result; void *kasan_ptr_result; +int kasan_int_result; + +static struct kunit_resource resource; +static struct kunit_kasan_expectation fail_data; +static bool multishot; + +static int kasan_test_init(struct kunit *test) +{ + /* + * Temporarily enable multi-shot mode and set panic_on_warn=0. + * Otherwise, we'd only get a report for the first case. + */ + multishot = kasan_save_enable_multi_shot(); + + return 0; +} + +static void kasan_test_exit(struct kunit *test) +{ + kasan_restore_multi_shot(multishot); +} + +/** + * KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does + * not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do + * Do not use this name for a KUnit resource outside here. + * + */ +#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \ + fail_data.report_expected = true; \ + fail_data.report_found = false; \ + kunit_add_named_resource(test, \ + NULL, \ + NULL, \ + &resource, \ + "kasan_data", &fail_data); \ + condition; \ + KUNIT_EXPECT_EQ(test, \ + fail_data.report_expected, \ + fail_data.report_found); \ +} while (0) + +
/* * Note: test functions are marked noinline so that their names appear in * reports. */ - static noinline void __init kmalloc_oob_right(void) { char *ptr; diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 51ec45407a0b..90a1348c8b81 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -33,6 +33,8 @@
#include <asm/sections.h>
+#include <kunit/test.h> + #include "kasan.h" #include "../slab.h"
@@ -464,12 +466,37 @@ static bool report_enabled(void) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); }
+#if IS_ENABLED(CONFIG_KUNIT) +static void kasan_update_kunit_status(struct kunit *cur_test) +{ + struct kunit_resource *resource; + struct kunit_kasan_expectation *kasan_data; + + resource = kunit_find_named_resource(cur_test, "kasan_data"); + + if (!resource) { + kunit_set_failure(cur_test); + return; + } + + kasan_data = (struct kunit_kasan_expectation *)resource->data; + kasan_data->report_found = true; + kunit_put_resource(resource); +} +#endif /* IS_ENABLED(CONFIG_KUNIT) */ + void kasan_report_invalid_free(void *object, unsigned long ip) { unsigned long flags; u8 tag = get_tag(object);
object = reset_tag(object); + +#if IS_ENABLED(CONFIG_KUNIT) + if (current->kunit_test) + kasan_update_kunit_status(current->kunit_test); +#endif /* IS_ENABLED(CONFIG_KUNIT) */ + start_report(&flags); pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip); print_tags(tag, object); @@ -488,6 +515,11 @@ static void __kasan_report(unsigned long addr, size_t size, bool is_write, void *untagged_addr; unsigned long flags;
+#if IS_ENABLED(CONFIG_KUNIT) + if (current->kunit_test) + kasan_update_kunit_status(current->kunit_test); +#endif /* IS_ENABLED(CONFIG_KUNIT) */ + disable_trace_on_warning();
tagged_addr = (void *)addr;
From: Patricia Alfonso trishalfonso@google.com
Transfer all previous tests for KASAN to KUnit so they can be run more easily. Using kunit_tool, developers can run these tests with their other KUnit tests and see "pass" or "fail" with the appropriate KASAN report instead of needing to parse each KASAN report to test KASAN functionalities. All KASAN reports are still printed to dmesg.
Stack tests do not work properly when KASAN_STACK is enabled so those tests use a check for "if IS_ENABLED(CONFIG_KASAN_STACK)" so they only run if stack instrumentation is enabled. If KASAN_STACK is not enabled, KUnit will print a statement to let the user know this test was not run with KASAN_STACK enabled.
copy_user_test cannot be run in KUnit so there is a separate test file for those tests, which can be run as before as a module.
Signed-off-by: Patricia Alfonso trishalfonso@google.com Signed-off-by: David Gow davidgow@google.com Reviewed-by: Brendan Higgins brendanhiggins@google.com Reviewed-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com --- lib/Kconfig.kasan | 22 +- lib/Makefile | 7 +- lib/test_kasan.c | 901 ---------------------------------------------- 3 files changed, 21 insertions(+), 909 deletions(-) delete mode 100644 lib/test_kasan.c
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 34b84bcbd3d9..a9f7451c541d 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -162,10 +162,22 @@ config KASAN_VMALLOC for KASAN to detect more sorts of errors (and to support vmapped stacks), but at the cost of higher memory usage.
-config TEST_KASAN - tristate "Module for testing KASAN for bug detection" - depends on m && KASAN +config KASAN_KUNIT_TEST + tristate "KUnit-compatible tests of KASAN bug detection capabilities" if !KUNIT_ALL_TESTS + depends on KASAN && KUNIT + default KUNIT_ALL_TESTS help - This is a test module doing various nasty things like - out of bounds accesses, use after free. It is useful for testing + This is a KUnit test suite doing various nasty things like + out of bounds and use after free accesses. It is useful for testing kernel debugging features like KASAN. + + For more information on KUnit and unit tests in general, please refer + to the KUnit documentation in Documentation/dev-tools/kunit + +config TEST_KASAN_MODULE + tristate "KUnit-incompatible tests of KASAN bug detection capabilities" + depends on m && KASAN + help + This is a part of the KASAN test suite that is incompatible with + KUnit. Currently includes tests that do bad copy_from/to_user + accesses. diff --git a/lib/Makefile b/lib/Makefile index b1c42c10073b..24a5c3cc7262 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -64,9 +64,10 @@ CFLAGS_test_bitops.o += -Werror obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o obj-$(CONFIG_TEST_IDA) += test_ida.o -obj-$(CONFIG_TEST_KASAN) += test_kasan.o -CFLAGS_test_kasan.o += -fno-builtin -CFLAGS_test_kasan.o += $(call cc-disable-warning, vla) +obj-$(CONFIG_KASAN_KUNIT_TEST) += kasan_kunit.o +CFLAGS_kasan_kunit.o += -fno-builtin +CFLAGS_kasan_kunit.o += $(call cc-disable-warning, vla) +obj-$(CONFIG_TEST_KASAN_MODULE) += test_kasan_module.o obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla) UBSAN_SANITIZE_test_ubsan.o := y diff --git a/lib/test_kasan.c b/lib/test_kasan.c deleted file mode 100644 index 842adcd30943..000000000000 --- a/lib/test_kasan.c +++ /dev/null @@ -1,901 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * - * Copyright (c) 2014 Samsung Electronics Co., Ltd. - * Author: Andrey Ryabinin a.ryabinin@samsung.com - */ - -#define pr_fmt(fmt) "kasan test: %s " fmt, __func__ - -#include <linux/bitops.h> -#include <linux/delay.h> -#include <linux/kasan.h> -#include <linux/kernel.h> -#include <linux/mm.h> -#include <linux/mman.h> -#include <linux/module.h> -#include <linux/printk.h> -#include <linux/slab.h> -#include <linux/string.h> -#include <linux/uaccess.h> -#include <linux/io.h> -#include <linux/vmalloc.h> - -#include <asm/page.h> - -#include <kunit/test.h> - -/* - * We assign some test results to these globals to make sure the tests - * are not eliminated as dead code. - */ - -void *kasan_ptr_result; -int kasan_int_result; - -static struct kunit_resource resource; -static struct kunit_kasan_expectation fail_data; -static bool multishot; - -static int kasan_test_init(struct kunit *test) -{ - /* - * Temporarily enable multi-shot mode and set panic_on_warn=0. - * Otherwise, we'd only get a report for the first case. - */ - multishot = kasan_save_enable_multi_shot(); - - return 0; -} - -static void kasan_test_exit(struct kunit *test) -{ - kasan_restore_multi_shot(multishot); -} - -/** - * KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does - * not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do - * Do not use this name for a KUnit resource outside here. - * - */ -#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \ - fail_data.report_expected = true; \ - fail_data.report_found = false; \ - kunit_add_named_resource(test, \ - NULL, \ - NULL, \ - &resource, \ - "kasan_data", &fail_data); \ - condition; \ - KUNIT_EXPECT_EQ(test, \ - fail_data.report_expected, \ - fail_data.report_found); \ -} while (0) - - - -/* - * Note: test functions are marked noinline so that their names appear in - * reports. - */ -static noinline void __init kmalloc_oob_right(void) -{ - char *ptr; - size_t size = 123; - - pr_info("out-of-bounds to right\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - ptr[size] = 'x'; - kfree(ptr); -} - -static noinline void __init kmalloc_oob_left(void) -{ - char *ptr; - size_t size = 15; - - pr_info("out-of-bounds to left\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - *ptr = *(ptr - 1); - kfree(ptr); -} - -static noinline void __init kmalloc_node_oob_right(void) -{ - char *ptr; - size_t size = 4096; - - pr_info("kmalloc_node(): out-of-bounds to right\n"); - ptr = kmalloc_node(size, GFP_KERNEL, 0); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - ptr[size] = 0; - kfree(ptr); -} - -#ifdef CONFIG_SLUB -static noinline void __init kmalloc_pagealloc_oob_right(void) -{ - char *ptr; - size_t size = KMALLOC_MAX_CACHE_SIZE + 10; - - /* Allocate a chunk that does not fit into a SLUB cache to trigger - * the page allocator fallback. - */ - pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - ptr[size] = 0; - kfree(ptr); -} - -static noinline void __init kmalloc_pagealloc_uaf(void) -{ - char *ptr; - size_t size = KMALLOC_MAX_CACHE_SIZE + 10; - - pr_info("kmalloc pagealloc allocation: use-after-free\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - kfree(ptr); - ptr[0] = 0; -} - -static noinline void __init kmalloc_pagealloc_invalid_free(void) -{ - char *ptr; - size_t size = KMALLOC_MAX_CACHE_SIZE + 10; - - pr_info("kmalloc pagealloc allocation: invalid-free\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - kfree(ptr + 1); -} -#endif - -static noinline void __init kmalloc_large_oob_right(void) -{ - char *ptr; - size_t size = KMALLOC_MAX_CACHE_SIZE - 256; - /* Allocate a chunk that is large enough, but still fits into a slab - * and does not trigger the page allocator fallback in SLUB. - */ - pr_info("kmalloc large allocation: out-of-bounds to right\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - ptr[size] = 0; - kfree(ptr); -} - -static noinline void __init kmalloc_oob_krealloc_more(void) -{ - char *ptr1, *ptr2; - size_t size1 = 17; - size_t size2 = 19; - - pr_info("out-of-bounds after krealloc more\n"); - ptr1 = kmalloc(size1, GFP_KERNEL); - ptr2 = krealloc(ptr1, size2, GFP_KERNEL); - if (!ptr1 || !ptr2) { - pr_err("Allocation failed\n"); - kfree(ptr1); - kfree(ptr2); - return; - } - - ptr2[size2] = 'x'; - kfree(ptr2); -} - -static noinline void __init kmalloc_oob_krealloc_less(void) -{ - char *ptr1, *ptr2; - size_t size1 = 17; - size_t size2 = 15; - - pr_info("out-of-bounds after krealloc less\n"); - ptr1 = kmalloc(size1, GFP_KERNEL); - ptr2 = krealloc(ptr1, size2, GFP_KERNEL); - if (!ptr1 || !ptr2) { - pr_err("Allocation failed\n"); - kfree(ptr1); - return; - } - ptr2[size2] = 'x'; - kfree(ptr2); -} - -static noinline void __init kmalloc_oob_16(void) -{ - struct { - u64 words[2]; - } *ptr1, *ptr2; - - pr_info("kmalloc out-of-bounds for 16-bytes access\n"); - ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); - ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); - if (!ptr1 || !ptr2) { - pr_err("Allocation failed\n"); - kfree(ptr1); - kfree(ptr2); - return; - } - *ptr1 = *ptr2; - kfree(ptr1); - kfree(ptr2); -} - -static noinline void __init kmalloc_oob_memset_2(void) -{ - char *ptr; - size_t size = 8; - - pr_info("out-of-bounds in memset2\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset(ptr+7, 0, 2); - kfree(ptr); -} - -static noinline void __init kmalloc_oob_memset_4(void) -{ - char *ptr; - size_t size = 8; - - pr_info("out-of-bounds in memset4\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset(ptr+5, 0, 4); - kfree(ptr); -} - - -static noinline void __init kmalloc_oob_memset_8(void) -{ - char *ptr; - size_t size = 8; - - pr_info("out-of-bounds in memset8\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset(ptr+1, 0, 8); - kfree(ptr); -} - -static noinline void __init kmalloc_oob_memset_16(void) -{ - char *ptr; - size_t size = 16; - - pr_info("out-of-bounds in memset16\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset(ptr+1, 0, 16); - kfree(ptr); -} - -static noinline void __init kmalloc_oob_in_memset(void) -{ - char *ptr; - size_t size = 666; - - pr_info("out-of-bounds in memset\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset(ptr, 0, size+5); - kfree(ptr); -} - -static noinline void __init kmalloc_memmove_invalid_size(void) -{ - char *ptr; - size_t size = 64; - volatile size_t invalid_size = -2; - - pr_info("invalid size in memmove\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - memset((char *)ptr, 0, 64); - memmove((char *)ptr, (char *)ptr + 4, invalid_size); - kfree(ptr); -} - -static noinline void __init kmalloc_uaf(void) -{ - char *ptr; - size_t size = 10; - - pr_info("use-after-free\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - kfree(ptr); - *(ptr + 8) = 'x'; -} - -static noinline void __init kmalloc_uaf_memset(void) -{ - char *ptr; - size_t size = 33; - - pr_info("use-after-free in memset\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - kfree(ptr); - memset(ptr, 0, size); -} - -static noinline void __init kmalloc_uaf2(void) -{ - char *ptr1, *ptr2; - size_t size = 43; - - pr_info("use-after-free after another kmalloc\n"); - ptr1 = kmalloc(size, GFP_KERNEL); - if (!ptr1) { - pr_err("Allocation failed\n"); - return; - } - - kfree(ptr1); - ptr2 = kmalloc(size, GFP_KERNEL); - if (!ptr2) { - pr_err("Allocation failed\n"); - return; - } - - ptr1[40] = 'x'; - if (ptr1 == ptr2) - pr_err("Could not detect use-after-free: ptr1 == ptr2\n"); - kfree(ptr2); -} - -static noinline void __init kfree_via_page(void) -{ - char *ptr; - size_t size = 8; - struct page *page; - unsigned long offset; - - pr_info("invalid-free false positive (via page)\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - page = virt_to_page(ptr); - offset = offset_in_page(ptr); - kfree(page_address(page) + offset); -} - -static noinline void __init kfree_via_phys(void) -{ - char *ptr; - size_t size = 8; - phys_addr_t phys; - - pr_info("invalid-free false positive (via phys)\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - phys = virt_to_phys(ptr); - kfree(phys_to_virt(phys)); -} - -static noinline void __init kmem_cache_oob(void) -{ - char *p; - size_t size = 200; - struct kmem_cache *cache = kmem_cache_create("test_cache", - size, 0, - 0, NULL); - if (!cache) { - pr_err("Cache allocation failed\n"); - return; - } - pr_info("out-of-bounds in kmem_cache_alloc\n"); - p = kmem_cache_alloc(cache, GFP_KERNEL); - if (!p) { - pr_err("Allocation failed\n"); - kmem_cache_destroy(cache); - return; - } - - *p = p[size]; - kmem_cache_free(cache, p); - kmem_cache_destroy(cache); -} - -static noinline void __init memcg_accounted_kmem_cache(void) -{ - int i; - char *p; - size_t size = 200; - struct kmem_cache *cache; - - cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL); - if (!cache) { - pr_err("Cache allocation failed\n"); - return; - } - - pr_info("allocate memcg accounted object\n"); - /* - * Several allocations with a delay to allow for lazy per memcg kmem - * cache creation. - */ - for (i = 0; i < 5; i++) { - p = kmem_cache_alloc(cache, GFP_KERNEL); - if (!p) - goto free_cache; - - kmem_cache_free(cache, p); - msleep(100); - } - -free_cache: - kmem_cache_destroy(cache); -} - -static char global_array[10]; - -static noinline void __init kasan_global_oob(void) -{ - volatile int i = 3; - char *p = &global_array[ARRAY_SIZE(global_array) + i]; - - pr_info("out-of-bounds global variable\n"); - *(volatile char *)p; -} - -static noinline void __init kasan_stack_oob(void) -{ - char stack_array[10]; - volatile int i = 0; - char *p = &stack_array[ARRAY_SIZE(stack_array) + i]; - - pr_info("out-of-bounds on stack\n"); - *(volatile char *)p; -} - -static noinline void __init ksize_unpoisons_memory(void) -{ - char *ptr; - size_t size = 123, real_size; - - pr_info("ksize() unpoisons the whole allocated chunk\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - real_size = ksize(ptr); - /* This access doesn't trigger an error. */ - ptr[size] = 'x'; - /* This one does. */ - ptr[real_size] = 'y'; - kfree(ptr); -} - -static noinline void __init copy_user_test(void) -{ - char *kmem; - char __user *usermem; - size_t size = 10; - int unused; - - kmem = kmalloc(size, GFP_KERNEL); - if (!kmem) - return; - - usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE, - PROT_READ | PROT_WRITE | PROT_EXEC, - MAP_ANONYMOUS | MAP_PRIVATE, 0); - if (IS_ERR(usermem)) { - pr_err("Failed to allocate user memory\n"); - kfree(kmem); - return; - } - - pr_info("out-of-bounds in copy_from_user()\n"); - unused = copy_from_user(kmem, usermem, size + 1); - - pr_info("out-of-bounds in copy_to_user()\n"); - unused = copy_to_user(usermem, kmem, size + 1); - - pr_info("out-of-bounds in __copy_from_user()\n"); - unused = __copy_from_user(kmem, usermem, size + 1); - - pr_info("out-of-bounds in __copy_to_user()\n"); - unused = __copy_to_user(usermem, kmem, size + 1); - - pr_info("out-of-bounds in __copy_from_user_inatomic()\n"); - unused = __copy_from_user_inatomic(kmem, usermem, size + 1); - - pr_info("out-of-bounds in __copy_to_user_inatomic()\n"); - unused = __copy_to_user_inatomic(usermem, kmem, size + 1); - - pr_info("out-of-bounds in strncpy_from_user()\n"); - unused = strncpy_from_user(kmem, usermem, size + 1); - - vm_munmap((unsigned long)usermem, PAGE_SIZE); - kfree(kmem); -} - -static noinline void __init kasan_alloca_oob_left(void) -{ - volatile int i = 10; - char alloca_array[i]; - char *p = alloca_array - 1; - - pr_info("out-of-bounds to left on alloca\n"); - *(volatile char *)p; -} - -static noinline void __init kasan_alloca_oob_right(void) -{ - volatile int i = 10; - char alloca_array[i]; - char *p = alloca_array + i; - - pr_info("out-of-bounds to right on alloca\n"); - *(volatile char *)p; -} - -static noinline void __init kmem_cache_double_free(void) -{ - char *p; - size_t size = 200; - struct kmem_cache *cache; - - cache = kmem_cache_create("test_cache", size, 0, 0, NULL); - if (!cache) { - pr_err("Cache allocation failed\n"); - return; - } - pr_info("double-free on heap object\n"); - p = kmem_cache_alloc(cache, GFP_KERNEL); - if (!p) { - pr_err("Allocation failed\n"); - kmem_cache_destroy(cache); - return; - } - - kmem_cache_free(cache, p); - kmem_cache_free(cache, p); - kmem_cache_destroy(cache); -} - -static noinline void __init kmem_cache_invalid_free(void) -{ - char *p; - size_t size = 200; - struct kmem_cache *cache; - - cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU, - NULL); - if (!cache) { - pr_err("Cache allocation failed\n"); - return; - } - pr_info("invalid-free of heap object\n"); - p = kmem_cache_alloc(cache, GFP_KERNEL); - if (!p) { - pr_err("Allocation failed\n"); - kmem_cache_destroy(cache); - return; - } - - /* Trigger invalid free, the object doesn't get freed */ - 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 noinline void __init kasan_memchr(void) -{ - char *ptr; - size_t size = 24; - - pr_info("out-of-bounds in memchr\n"); - ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); - if (!ptr) - return; - - kasan_ptr_result = memchr(ptr, '1', size + 1); - kfree(ptr); -} - -static noinline void __init kasan_memcmp(void) -{ - char *ptr; - size_t size = 24; - int arr[9]; - - pr_info("out-of-bounds in memcmp\n"); - ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); - if (!ptr) - return; - - memset(arr, 0, sizeof(arr)); - kasan_int_result = memcmp(ptr, arr, size + 1); - kfree(ptr); -} - -static noinline void __init kasan_strings(void) -{ - char *ptr; - size_t size = 24; - - pr_info("use-after-free in strchr\n"); - ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); - if (!ptr) - return; - - 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; - kasan_ptr_result = strchr(ptr, '1'); - - pr_info("use-after-free in strrchr\n"); - kasan_ptr_result = strrchr(ptr, '1'); - - pr_info("use-after-free in strcmp\n"); - kasan_int_result = strcmp(ptr, "2"); - - pr_info("use-after-free in strncmp\n"); - kasan_int_result = strncmp(ptr, "2", 1); - - pr_info("use-after-free in strlen\n"); - kasan_int_result = strlen(ptr); - - pr_info("use-after-free in strnlen\n"); - kasan_int_result = strnlen(ptr, 1); -} - -static noinline void __init kasan_bitops(void) -{ - /* - * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes; - * this way we do not actually corrupt other memory. - */ - long *bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL); - if (!bits) - return; - - /* - * 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. - */ - pr_info("out-of-bounds in set_bit\n"); - set_bit(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in __set_bit\n"); - __set_bit(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in clear_bit\n"); - clear_bit(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in __clear_bit\n"); - __clear_bit(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in clear_bit_unlock\n"); - clear_bit_unlock(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in __clear_bit_unlock\n"); - __clear_bit_unlock(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in change_bit\n"); - change_bit(BITS_PER_LONG, bits); - - pr_info("out-of-bounds in __change_bit\n"); - __change_bit(BITS_PER_LONG, bits); - - /* - * Below calls try to access bit beyond allocated memory. - */ - pr_info("out-of-bounds in test_and_set_bit\n"); - test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in __test_and_set_bit\n"); - __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in test_and_set_bit_lock\n"); - test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in test_and_clear_bit\n"); - test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in __test_and_clear_bit\n"); - __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in test_and_change_bit\n"); - test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in __test_and_change_bit\n"); - __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - - pr_info("out-of-bounds in test_bit\n"); - kasan_int_result = test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits); - -#if defined(clear_bit_unlock_is_negative_byte) - pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n"); - kasan_int_result = clear_bit_unlock_is_negative_byte(BITS_PER_LONG + - BITS_PER_BYTE, bits); -#endif - kfree(bits); -} - -static noinline void __init kmalloc_double_kzfree(void) -{ - char *ptr; - size_t size = 16; - - pr_info("double-free (kzfree)\n"); - ptr = kmalloc(size, GFP_KERNEL); - if (!ptr) { - pr_err("Allocation failed\n"); - return; - } - - kzfree(ptr); - kzfree(ptr); -} - -#ifdef CONFIG_KASAN_VMALLOC -static noinline void __init vmalloc_oob(void) -{ - void *area; - - pr_info("vmalloc out-of-bounds\n"); - - /* - * We have to be careful not to hit the guard page. - * The MMU will catch that and crash us. - */ - area = vmalloc(3000); - if (!area) { - pr_err("Allocation failed\n"); - return; - } - - ((volatile char *)area)[3100]; - vfree(area); -} -#else -static void __init vmalloc_oob(void) {} -#endif - -static int __init kmalloc_tests_init(void) -{ - /* - * Temporarily enable multi-shot mode. Otherwise, we'd only get a - * report for the first case. - */ - bool multishot = kasan_save_enable_multi_shot(); - - kmalloc_oob_right(); - kmalloc_oob_left(); - kmalloc_node_oob_right(); -#ifdef CONFIG_SLUB - kmalloc_pagealloc_oob_right(); - kmalloc_pagealloc_uaf(); - kmalloc_pagealloc_invalid_free(); -#endif - kmalloc_large_oob_right(); - kmalloc_oob_krealloc_more(); - kmalloc_oob_krealloc_less(); - kmalloc_oob_16(); - kmalloc_oob_in_memset(); - kmalloc_oob_memset_2(); - kmalloc_oob_memset_4(); - kmalloc_oob_memset_8(); - kmalloc_oob_memset_16(); - kmalloc_memmove_invalid_size(); - kmalloc_uaf(); - kmalloc_uaf_memset(); - kmalloc_uaf2(); - kfree_via_page(); - kfree_via_phys(); - kmem_cache_oob(); - memcg_accounted_kmem_cache(); - kasan_stack_oob(); - kasan_global_oob(); - kasan_alloca_oob_left(); - kasan_alloca_oob_right(); - ksize_unpoisons_memory(); - copy_user_test(); - kmem_cache_double_free(); - kmem_cache_invalid_free(); - kasan_memchr(); - kasan_memcmp(); - kasan_strings(); - kasan_bitops(); - kmalloc_double_kzfree(); - vmalloc_oob(); - - kasan_restore_multi_shot(multishot); - - return -EAGAIN; -} - -module_init(kmalloc_tests_init); -MODULE_LICENSE("GPL");
From: Patricia Alfonso trishalfonso@google.com
Include documentation on how to test KASAN using CONFIG_TEST_KASAN_KUNIT and CONFIG_TEST_KASAN_MODULE.
Signed-off-by: Patricia Alfonso trishalfonso@google.com Signed-off-by: David Gow davidgow@google.com Reviewed-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com Acked-by: Brendan Higgins brendanhiggins@google.com --- Documentation/dev-tools/kasan.rst | 70 +++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+)
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index c652d740735d..1f9a75df0fc8 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -281,3 +281,73 @@ unmapped. This will require changes in arch-specific code.
This allows ``VMAP_STACK`` support on x86, and can simplify support of architectures that do not have a fixed module region. + +CONFIG_KASAN_KUNIT_TEST & CONFIG_TEST_KASAN_MODULE +-------------------------------------------------- + +``CONFIG_KASAN_KUNIT_TEST`` utilizes the KUnit Test Framework for testing. +This means each test focuses on a small unit of functionality and +there are a few ways these tests can be run. + +Each test will print the KASAN report if an error is detected and then +print the number of the test and the status of the test: + +pass:: + + ok 28 - kmalloc_double_kzfree +or, if kmalloc failed:: + + # kmalloc_large_oob_right: ASSERTION FAILED at lib/test_kasan.c:163 + Expected ptr is not null, but is + not ok 4 - kmalloc_large_oob_right +or, if a KASAN report was expected, but not found:: + + # kmalloc_double_kzfree: EXPECTATION FAILED at lib/test_kasan.c:629 + Expected kasan_data->report_expected == kasan_data->report_found, but + kasan_data->report_expected == 1 + kasan_data->report_found == 0 + not ok 28 - kmalloc_double_kzfree + +All test statuses are tracked as they run and an overall status will +be printed at the end:: + + ok 1 - kasan_kunit_test + +or:: + + not ok 1 - kasan_kunit_test + +(1) Loadable Module +~~~~~~~~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` enabled, ``CONFIG_KASAN_KUNIT_TEST`` can be built as +a loadable module and run on any architecture that supports KASAN +using something like insmod or modprobe. + +(2) Built-In +~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` built-in, ``CONFIG_KASAN_KUNIT_TEST`` can be built-in +on any architecure that supports KASAN. These and any other KUnit +tests enabled will run and print the results at boot as a late-init +call. + +(3) Using kunit_tool +~~~~~~~~~~~~~~~~~~~~~ + +With ``CONFIG_KUNIT`` and ``CONFIG_KASAN_KUNIT_TEST`` built-in, we can also +use kunit_tool to see the results of these along with other KUnit +tests in a more readable way. This will not print the KASAN reports +of tests that passed. Use `KUnit documentation https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html`_ for more up-to-date +information on kunit_tool. + +.. _KUnit: https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html + +``CONFIG_TEST_KASAN_MODULE`` is a set of KASAN tests that could not be +converted to KUnit. These tests can be run only as a module with +``CONFIG_TEST_KASAN_MODULE`` built as a loadable module and +``CONFIG_KASAN`` built-in. The type of error expected and the +function being run is printed before the expression expected to give +an error. Then the error is printed, if found, and that test +should be interpretted to pass only if the error was the one expected +by the test.
KASAN errors will currently trigger a panic when panic_on_warn is set. This renders kasan_multishot useless, as further KASAN errors won't be reported if the kernel has already paniced. By making kasan_multishot disable this behaviour for KASAN errors, we can still have the benefits of panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot.
This is particularly important when running KASAN tests, which need to trigger multiple KASAN errors: previously these would panic the system if panic_on_warn was set, now they can run (and will panic the system should non-KASAN warnings show up).
Signed-off-by: David Gow davidgow@google.com Reviewed-by: Andrey Konovalov andreyknvl@google.com Reviewed-by: Brendan Higgins brendanhiggins@google.com --- mm/kasan/report.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 90a1348c8b81..c83d6fde9ee4 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -95,7 +95,7 @@ static void end_report(unsigned long *flags) pr_err("==================================================================\n"); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irqrestore(&report_lock, *flags); - if (panic_on_warn) { + if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) { /* * This thread may hit another WARN() in the panic path. * Resetting this prevents additional WARN() from panicking the
On Fri, Jul 31, 2020 at 6:43 AM David Gow davidgow@google.com wrote:
This patchset contains everything needed to integrate KASAN and KUnit.
KUnit will be able to: (1) Fail tests when an unexpected KASAN error occurs (2) Pass tests when an expected KASAN error occurs
Convert KASAN tests to KUnit with the exception of copy_user_test because KUnit is unable to test those.
Add documentation on how to run the KASAN tests with KUnit and what to expect when running these tests.
This patchset depends on:
- "kunit: extend kunit resources API" [1]
- This is already present in the kselftest/kunit branch
I'd _really_ like to get this into 5.9 if possible: we also have some other changes which depend on some things here.
Hi David,
You'll need to rebase this on top of the mm tree, which currently contains Walter's patch titled "kasan: fix KASAN unit tests for tag-based KASAN".
There's also another patch that touches KASAN tests in the series I've just mailed titled "kasan: support stack instrumentation for tag-based mode".
Thanks!
Changes from v8:
- Rebased on top of kselftest/kunit
- (Which, with this patchset, should rebase cleanly on 5.8-rc7)
- Renamed the KUnit test suite, config name to patch the proposed naming guidelines for KUnit tests[6]
Changes from v7:
- Rebased on top of kselftest/kunit
- Rebased on top of v4 of the kunit resources API[1]
- Rebased on top of v4 of the FORTIFY_SOURCE fix[2,3,4]
- Updated the Kconfig entry to support KUNIT_ALL_TESTS
Changes from v6:
- Rebased on top of kselftest/kunit
- Rebased on top of Daniel Axtens' fix for FORTIFY_SOURCE incompatibilites [2]
- Removed a redundant report_enabled() check.
- Fixed some places with out of date Kconfig names in the documentation.
Changes from v5:
- Split out the panic_on_warn changes to a separate patch.
- Fix documentation to fewer to the new Kconfig names.
- Fix some changes which were in the wrong patch.
- Rebase on top of kselftest/kunit (currently identical to 5.7-rc1)
Changes from v4:
- KASAN no longer will panic on errors if both panic_on_warn and kasan_multishot are enabled.
- As a result, the KASAN tests will no-longer disable panic_on_warn.
- This also means panic_on_warn no-longer needs to be exported.
- The use of temporary "kasan_data" variables has been cleaned up somewhat.
- A potential refcount/resource leak should multiple KASAN errors appear during an assertion was fixed.
- Some wording changes to the KASAN test Kconfig entries.
Changes from v3:
- KUNIT_SET_KASAN_DATA and KUNIT_DO_EXPECT_KASAN_FAIL have been
combined and included in KUNIT_DO_EXPECT_KASAN_FAIL() instead.
- Reordered logic in kasan_update_kunit_status() in report.c to be
easier to read.
- Added comment to not use the name "kasan_data" for any kunit tests
outside of KUNIT_EXPECT_KASAN_FAIL().
Changes since v2:
- Due to Alan's changes in [1], KUnit can be built as a module.
- The name of the tests that could not be run with KUnit has been
changed to be more generic: test_kasan_module.
- Documentation on how to run the new KASAN tests and what to expect
when running them has been added.
- Some variables and functions are now static.
- Now save/restore panic_on_warn in a similar way to kasan_multi_shot
and renamed the init/exit functions to be more generic to accommodate.
- Due to [4] in kasan_strings, kasan_memchr, and
kasan_memcmp will fail if CONFIG_AMD_MEM_ENCRYPT is enabled so return early and print message explaining this circumstance.
- Changed preprocessor checks to C checks where applicable.
Changes since v1:
- Make use of Alan Maguire's suggestion to use his patch that allows static resources for integration instead of adding a new attribute to the kunit struct
- All KUNIT_EXPECT_KASAN_FAIL statements are local to each test
- The definition of KUNIT_EXPECT_KASAN_FAIL is local to the test_kasan.c file since it seems this is the only place this will be used.
- Integration relies on KUnit being builtin
- copy_user_test has been separated into its own file since KUnit is unable to test these. This can be run as a module just as before, using CONFIG_TEST_KASAN_USER
- The addition to the current task has been separated into its own patch as this is a significant enough change to be on its own.
[1] https://lore.kernel.org/linux-kselftest/CAFd5g46Uu_5TG89uOm0Dj5CMq+11cwjBnsd... [2] https://lore.kernel.org/linux-mm/20200424145521.8203-1-dja@axtens.net/ [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... [4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... [5] https://bugzilla.kernel.org/show_bug.cgi?id=206337 [6] https://lore.kernel.org/linux-kselftest/20200620054944.167330-1-davidgow@goo...
David Gow (1): mm: kasan: Do not panic if both panic_on_warn and kasan_multishot set
Patricia Alfonso (4): Add KUnit Struct to Current Task KUnit: KASAN Integration KASAN: Port KASAN Tests to KUnit KASAN: Testing Documentation
Documentation/dev-tools/kasan.rst | 70 +++ include/kunit/test.h | 5 + include/linux/kasan.h | 6 + include/linux/sched.h | 4 + lib/Kconfig.kasan | 22 +- lib/Makefile | 7 +- lib/kunit/test.c | 13 +- lib/test_kasan.c | 858 ------------------------------ mm/kasan/report.c | 34 +- 9 files changed, 147 insertions(+), 872 deletions(-) delete mode 100644 lib/test_kasan.c
-- 2.28.0.163.g6104cc2f0b6-goog
On Fri, Jul 31, 2020 at 9:25 PM 'Andrey Konovalov' via kasan-dev kasan-dev@googlegroups.com wrote:
On Fri, Jul 31, 2020 at 6:43 AM David Gow davidgow@google.com wrote:
This patchset contains everything needed to integrate KASAN and KUnit.
KUnit will be able to: (1) Fail tests when an unexpected KASAN error occurs (2) Pass tests when an expected KASAN error occurs
Convert KASAN tests to KUnit with the exception of copy_user_test because KUnit is unable to test those.
Add documentation on how to run the KASAN tests with KUnit and what to expect when running these tests.
This patchset depends on:
- "kunit: extend kunit resources API" [1]
- This is already present in the kselftest/kunit branch
I'd _really_ like to get this into 5.9 if possible: we also have some other changes which depend on some things here.
Hi David,
You'll need to rebase this on top of the mm tree, which currently contains Walter's patch titled "kasan: fix KASAN unit tests for tag-based KASAN".
There's also another patch that touches KASAN tests in the series I've just mailed titled "kasan: support stack instrumentation for tag-based mode".
Thanks!
I've rebased this on top of a linux-next (with the pending KUnit patches from kselftest/kunit and the "kasan: support stack instrumentation for tag-based mode" patchset applied): https://lore.kernel.org/linux-kselftest/20200801070924.1786166-1-davidgow@go...
Note that the RCU test doesn't seem to be compatible with KUnit's KASAN integration at present: I'm no expert on RCU, but it looks like the current test context might not be propagated to the callback, so expecting the failure doesn't work. Given that KUnit also doesn't look for the aux stacks (just that a failure occurred), it seemed best to avoid trying to port that one to KUnit, so I've left it in the test_kasan_module.c file. It may be possible to port it at a later date.
Note that I don't have an arm64 setup here, so I haven't actually tested the tag-based KASAN stuff yet.
Cheers, -- David
linux-kselftest-mirror@lists.linaro.org
-
Andrey Konovalov -
David Gow