[PATCH 1/2] lib: kasan: remove reference of non-existent test_kasan.o
Ahmad Fatoum
a.fatoum at pengutronix.de
Mon Sep 28 10:59:40 EDT 2020
On 9/28/20 4:58 PM, Sascha Hauer wrote:
> On Mon, Sep 28, 2020 at 04:41:45PM +0200, Ahmad Fatoum wrote:
>> We don't have anything that test_kasan.o can be generated out of,
>> thus drop it to fix the build.
>>
>> It would still be nice to have this as a command, but that
>> should be a separate patch.
>>
>> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>> ---
>> lib/kasan/Makefile | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> I prefer to add the code that I have forgotten to git add ;)
Wouldn't locating it in commands/ be better?
>
> Sascha
>
> ----------------------8<-----------------
>
>
> From ff5cbfcbbe21d7883e3ce661fec3751f7cb7e58c Mon Sep 17 00:00:00 2001
> From: Sascha Hauer <s.hauer at pengutronix.de>
> Date: Mon, 28 Sep 2020 16:56:36 +0200
> Subject: [PATCH] KASan: Add missing test code
>
> Add missing test code.
>
> Fixes: 6cd9d2d600 ("Add KASan support")
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
> lib/kasan/test_kasan.c | 478 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 478 insertions(+)
> create mode 100644 lib/kasan/test_kasan.c
>
> diff --git a/lib/kasan/test_kasan.c b/lib/kasan/test_kasan.c
> new file mode 100644
> index 0000000000..e472bb3499
> --- /dev/null
> +++ b/lib/kasan/test_kasan.c
> @@ -0,0 +1,478 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + *
> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> + * Author: Andrey Ryabinin <a.ryabinin at samsung.com>
> + */
> +
> +#define pr_fmt(fmt) "kasan test: " fmt
> +
> +#include <common.h>
> +#include <command.h>
> +#include <complete.h>
> +
> +#include "kasan.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;
> +
> +/*
> + * Note: test functions are marked noinline so that their names appear in
> + * reports.
> + */
> +
> +static noinline void malloc_oob_right(void)
> +{
> + char *ptr;
> + size_t size = 123;
> +
> + pr_info("out-of-bounds to right\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + ptr[size] = 'x';
> +
> + free(ptr);
> +}
> +
> +static noinline void malloc_oob_left(void)
> +{
> + char *ptr;
> + size_t size = 15;
> +
> + pr_info("out-of-bounds to left\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + *ptr = *(ptr - 1);
> + free(ptr);
> +}
> +
> +static noinline void malloc_oob_realloc_more(void)
> +{
> + char *ptr1, *ptr2;
> + size_t size1 = 17;
> + size_t size2 = 19;
> +
> + pr_info("out-of-bounds after krealloc more\n");
> + ptr1 = malloc(size1);
> + ptr2 = realloc(ptr1, size2);
> + if (!ptr1 || !ptr2) {
> + pr_err("Allocation failed\n");
> + free(ptr1);
> + free(ptr2);
> + return;
> + }
> +
> + ptr2[size2] = 'x';
> +
> + free(ptr2);
> +}
> +
> +static noinline void malloc_oob_realloc_less(void)
> +{
> + char *ptr1, *ptr2;
> + size_t size1 = 17;
> + size_t size2 = 15;
> +
> + pr_info("out-of-bounds after krealloc less\n");
> + ptr1 = malloc(size1);
> + ptr2 = realloc(ptr1, size2);
> + if (!ptr1 || !ptr2) {
> + pr_err("Allocation failed\n");
> + free(ptr1);
> + return;
> + }
> +
> + ptr2[size2] = 'x';
> +
> + free(ptr2);
> +}
> +
> +static noinline void malloc_oob_16(void)
> +{
> + struct {
> + u64 words[2];
> + } *ptr1, *ptr2;
> +
> + pr_info("malloc out-of-bounds for 16-bytes access\n");
> + ptr1 = malloc(sizeof(*ptr1) - 3);
> + ptr2 = malloc(sizeof(*ptr2));
> + if (!ptr1 || !ptr2) {
> + pr_err("Allocation failed\n");
> + free(ptr1);
> + free(ptr2);
> + return;
> + }
> + *ptr1 = *ptr2;
> + free(ptr1);
> + free(ptr2);
> +}
> +
> +static noinline void malloc_oob_memset_2(void)
> +{
> + char *ptr;
> + size_t size = 8;
> +
> + pr_info("out-of-bounds in memset2\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + memset(ptr + 7, 0, 2);
> +
> + free(ptr);
> +}
> +
> +static noinline void malloc_oob_memset_4(void)
> +{
> + char *ptr;
> + size_t size = 8;
> +
> + pr_info("out-of-bounds in memset4\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + memset(ptr + 5, 0, 4);
> +
> + free(ptr);
> +}
> +
> +
> +static noinline void malloc_oob_memset_8(void)
> +{
> + char *ptr;
> + size_t size = 8;
> +
> + pr_info("out-of-bounds in memset8\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + memset(ptr + 1, 0, 8);
> +
> + free(ptr);
> +}
> +
> +static noinline void malloc_oob_memset_16(void)
> +{
> + char *ptr;
> + size_t size = 16;
> +
> + pr_info("out-of-bounds in memset16\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + memset(ptr + 1, 0, 16);
> +
> + free(ptr);
> +}
> +
> +static noinline void malloc_oob_in_memset(void)
> +{
> + char *ptr;
> + size_t size = 666;
> +
> + pr_info("out-of-bounds in memset\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + memset(ptr, 0, size + 5);
> +
> + free(ptr);
> +}
> +
> +static noinline void malloc_uaf(void)
> +{
> + char *ptr;
> + size_t size = 10;
> +
> + pr_info("use-after-free\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + free(ptr);
> + *(ptr + 8) = 'x';
> +}
> +
> +static noinline void malloc_uaf_memset(void)
> +{
> + char *ptr;
> + size_t size = 33;
> +
> + pr_info("use-after-free in memset\n");
> + ptr = malloc(size);
> + if (!ptr) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + free(ptr);
> + memset(ptr, 0, size);
> +}
> +
> +static noinline void malloc_uaf2(void)
> +{
> + char *ptr1, *ptr2;
> + size_t size = 43;
> +
> + pr_info("use-after-free after another malloc\n");
> + ptr1 = malloc(size);
> + if (!ptr1) {
> + pr_err("Allocation failed\n");
> + return;
> + }
> +
> + free(ptr1);
> + ptr2 = malloc(size);
> + 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");
> + free(ptr2);
> +}
> +
> +static char global_array[10];
> +
> +static noinline void 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 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 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 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 kasan_memchr(void)
> +{
> + char *ptr;
> + size_t size = 24;
> +
> + pr_info("out-of-bounds in memchr\n");
> + ptr = kzalloc(size, 0);
> + if (!ptr)
> + return;
> +
> + kasan_ptr_result = memchr(ptr, '1', size + 1);
> + free(ptr);
> +}
> +
> +static noinline void kasan_memcmp(void)
> +{
> + char *ptr;
> + size_t size = 24;
> + int arr[9];
> +
> + pr_info("out-of-bounds in memcmp\n");
> + ptr = kzalloc(size, 0);
> + if (!ptr)
> + return;
> +
> + memset(arr, 0, sizeof(arr));
> + kasan_int_result = memcmp(ptr, arr, size + 1);
> + free(ptr);
> +}
> +
> +static noinline void kasan_strings(void)
> +{
> + char *ptr;
> + size_t size = 24;
> +
> + pr_info("use-after-free in strchr\n");
> + ptr = malloc(size);
> + if (!ptr)
> + return;
> +
> + free(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 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 = xzalloc(sizeof(*bits) + 1);
> + 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 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_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
> + free(bits);
> +}
> +
> +static int do_kasan_test(int argc, char *argv[])
> +{
> + /*
> + * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> + * report for the first case.
> + */
> + bool multishot = kasan_save_enable_multi_shot();
> +
> + malloc_oob_right();
> + malloc_oob_left();
> + malloc_oob_realloc_more();
> + malloc_oob_realloc_less();
> + malloc_oob_16();
> + malloc_oob_in_memset();
> + malloc_oob_memset_2();
> + malloc_oob_memset_4();
> + malloc_oob_memset_8();
> + malloc_oob_memset_16();
> + malloc_uaf();
> + malloc_uaf_memset();
> + malloc_uaf2();
> + kasan_stack_oob();
> + kasan_global_oob();
> + kasan_alloca_oob_left();
> + kasan_alloca_oob_right();
> + kasan_memchr();
> + kasan_memcmp();
> + kasan_strings();
> + kasan_bitops();
> +
> + kasan_restore_multi_shot(multishot);
> +
> + return 0;
> +}
> +
> +BAREBOX_CMD_START(kasan_tests)
> + .cmd = do_kasan_test,
> + BAREBOX_CMD_DESC("Run KAsan tests")
> + BAREBOX_CMD_COMPLETE(empty_complete)
> +BAREBOX_CMD_END
>
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