From 854686f4edf483db1e0d26d972bdb8fb65c8bfaa Mon Sep 17 00:00:00 2001 From: Jinbum Park Date: Tue, 10 Apr 2018 16:32:58 -0700 Subject: [PATCH] lib: add testing module for UBSAN This is a test module for UBSAN. It triggers all undefined behaviors that linux supports now, and detect them. All test-cases have passed by compiling with gcc-5.5.0. If use gcc-4.9.x, misaligned, out-of-bounds, object-size-mismatch will not be detected. Because gcc-4.9.x doesn't support them. Link: http://lkml.kernel.org/r/20180309102247.GA2944@pjb1027-Latitude-E5410 Signed-off-by: Jinbum Park Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.ubsan | 7 +++ lib/Makefile | 2 + lib/test_ubsan.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 153 insertions(+) create mode 100644 lib/test_ubsan.c diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index a669c193b878..19d42ea75ec2 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -46,3 +46,10 @@ config UBSAN_NULL help This option enables detection of memory accesses via a null pointer. + +config TEST_UBSAN + tristate "Module for testing for undefined behavior detection" + depends on m && UBSAN + help + This is a test module for UBSAN. + It triggers various undefined behavior, and detect it. diff --git a/lib/Makefile b/lib/Makefile index 6200f978740d..ce20696d5a92 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -54,6 +54,8 @@ obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o obj-$(CONFIG_TEST_KASAN) += test_kasan.o CFLAGS_test_kasan.o += -fno-builtin +obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o +UBSAN_SANITIZE_test_ubsan.o := y obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o obj-$(CONFIG_TEST_LKM) += test_module.o diff --git a/lib/test_ubsan.c b/lib/test_ubsan.c new file mode 100644 index 000000000000..58dedff36b17 --- /dev/null +++ b/lib/test_ubsan.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include + +typedef void(*test_ubsan_fp)(void); + +static void test_ubsan_add_overflow(void) +{ + volatile int val = INT_MAX; + + val += 2; +} + +static void test_ubsan_sub_overflow(void) +{ + volatile int val = INT_MIN; + volatile int val2 = 2; + + val -= val2; +} + +static void test_ubsan_mul_overflow(void) +{ + volatile int val = INT_MAX / 2; + + val *= 3; +} + +static void test_ubsan_negate_overflow(void) +{ + volatile int val = INT_MIN; + + val = -val; +} + +static void test_ubsan_divrem_overflow(void) +{ + volatile int val = 16; + volatile int val2 = 0; + + val /= val2; +} + +static void test_ubsan_vla_bound_not_positive(void) +{ + volatile int size = -1; + char buf[size]; + + (void)buf; +} + +static void test_ubsan_shift_out_of_bounds(void) +{ + volatile int val = -1; + int val2 = 10; + + val2 <<= val; +} + +static void test_ubsan_out_of_bounds(void) +{ + volatile int i = 4, j = 5; + volatile int arr[i]; + + arr[j] = i; +} + +static void test_ubsan_load_invalid_value(void) +{ + volatile char *dst, *src; + bool val, val2, *ptr; + char c = 4; + + dst = (char *)&val; + src = &c; + *dst = *src; + + ptr = &val2; + val2 = val; +} + +static void test_ubsan_null_ptr_deref(void) +{ + volatile int *ptr = NULL; + int val; + + val = *ptr; +} + +void test_ubsan_misaligned_access(void) +{ + volatile char arr[5] __aligned(4) = {1, 2, 3, 4, 5}; + volatile int *ptr, val = 6; + + ptr = (int *)(arr + 1); + *ptr = val; +} + +static void test_ubsan_object_size_mismatch(void) +{ + /* "((aligned(8)))" helps this not into be misaligned for ptr-access. */ + volatile int val __aligned(8) = 4; + volatile long long *ptr, val2; + + ptr = (long long *)&val; + val2 = *ptr; +} + +static const test_ubsan_fp test_ubsan_array[] = { + test_ubsan_add_overflow, + test_ubsan_sub_overflow, + test_ubsan_mul_overflow, + test_ubsan_negate_overflow, + test_ubsan_divrem_overflow, + test_ubsan_vla_bound_not_positive, + test_ubsan_shift_out_of_bounds, + test_ubsan_out_of_bounds, + test_ubsan_load_invalid_value, + //test_ubsan_null_ptr_deref, /* exclude it because there is a crash */ + test_ubsan_misaligned_access, + test_ubsan_object_size_mismatch, +}; + +static int __init test_ubsan_init(void) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(test_ubsan_array); i++) + test_ubsan_array[i](); + + (void)test_ubsan_null_ptr_deref; /* to avoid unsed-function warning */ + return 0; +} +module_init(test_ubsan_init); + +static void __exit test_ubsan_exit(void) +{ + /* do nothing */ +} +module_exit(test_ubsan_exit); + +MODULE_AUTHOR("Jinbum Park "); +MODULE_LICENSE("GPL v2");