From: Marco Elver <elver@google.com>
To: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Will Deacon <will.deacon@arm.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Peter Collingbourne <pcc@google.com>,
Evgenii Stepanov <eugenis@google.com>,
Branislav Rankov <Branislav.Rankov@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 06/12] kasan: rework krealloc tests
Date: Wed, 3 Feb 2021 15:48:25 +0100 [thread overview]
Message-ID: <YBq3uZOKeRnW3eBl@elver.google.com> (raw)
In-Reply-To: <995edb531f4f976277d7da9ca8a78a96a2ea356e.1612208222.git.andreyknvl@google.com>
On Mon, Feb 01, 2021 at 08:43PM +0100, Andrey Konovalov wrote:
> This patch reworks KASAN-KUnit tests for krealloc() to:
>
> 1. Check both slab and page_alloc based krealloc() implementations.
> 2. Allow at least one full granule to fit between old and new sizes for
> each KASAN mode, and check accesses to that granule accordingly.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
> ---
> lib/test_kasan.c | 91 ++++++++++++++++++++++++++++++++++++++++++------
> 1 file changed, 81 insertions(+), 10 deletions(-)
>
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index 5699e43ca01b..2bb52853f341 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -258,11 +258,14 @@ static void kmalloc_large_oob_right(struct kunit *test)
> kfree(ptr);
> }
>
> -static void kmalloc_oob_krealloc_more(struct kunit *test)
> +static void krealloc_more_oob_helper(struct kunit *test,
> + size_t size1, size_t size2)
> {
> char *ptr1, *ptr2;
> - size_t size1 = 17;
> - size_t size2 = 19;
> + 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);
> @@ -270,15 +273,31 @@ static void kmalloc_oob_krealloc_more(struct kunit *test)
> ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
>
> - KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x');
> + /* 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 kmalloc_oob_krealloc_less(struct kunit *test)
> +static void krealloc_less_oob_helper(struct kunit *test,
> + size_t size1, size_t size2)
> {
> char *ptr1, *ptr2;
> - size_t size1 = 17;
> - size_t size2 = 15;
> + 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);
> @@ -286,10 +305,60 @@ static void kmalloc_oob_krealloc_less(struct kunit *test)
> ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
>
> - KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2 + OOB_TAG_OFF] = 'x');
> + /* 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 both middle and size1 should land in separate granules
middle, size1, and size2?
> + * and thus 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_pagealloc_more_oob(struct kunit *test)
> +{
> + /* page_alloc fallback in only implemented for SLUB. */
> + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
> +
> + krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
> + KMALLOC_MAX_CACHE_SIZE + 235);
> +}
> +
> +static void krealloc_pagealloc_less_oob(struct kunit *test)
> +{
> + /* page_alloc fallback in only implemented for SLUB. */
> + KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
> +
> + krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
> + KMALLOC_MAX_CACHE_SIZE + 201);
> +}
> +
> static void kmalloc_oob_16(struct kunit *test)
> {
> struct {
> @@ -983,8 +1052,10 @@ static struct kunit_case kasan_kunit_test_cases[] = {
> KUNIT_CASE(pagealloc_oob_right),
> KUNIT_CASE(pagealloc_uaf),
> KUNIT_CASE(kmalloc_large_oob_right),
> - KUNIT_CASE(kmalloc_oob_krealloc_more),
> - KUNIT_CASE(kmalloc_oob_krealloc_less),
> + KUNIT_CASE(krealloc_more_oob),
> + KUNIT_CASE(krealloc_less_oob),
> + KUNIT_CASE(krealloc_pagealloc_more_oob),
> + KUNIT_CASE(krealloc_pagealloc_less_oob),
> KUNIT_CASE(kmalloc_oob_16),
> KUNIT_CASE(kmalloc_uaf_16),
> KUNIT_CASE(kmalloc_oob_in_memset),
> --
> 2.30.0.365.g02bc693789-goog
>
next prev parent reply other threads:[~2021-02-03 14:48 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-01 19:43 [PATCH 00/12] kasan: optimizations and fixes for HW_TAGS Andrey Konovalov
2021-02-01 19:43 ` [PATCH 01/12] kasan, mm: don't save alloc stacks twice Andrey Konovalov
2021-02-02 16:06 ` Marco Elver
2021-02-02 18:01 ` Andrey Konovalov
2021-02-02 18:40 ` Marco Elver
2021-02-01 19:43 ` [PATCH 02/12] kasan, mm: optimize kmalloc poisoning Andrey Konovalov
2021-02-02 16:25 ` Marco Elver
2021-02-02 17:15 ` Andrey Konovalov
2021-02-02 17:39 ` Marco Elver
2021-02-01 19:43 ` [PATCH 03/12] kasan: optimize large " Andrey Konovalov
2021-02-02 16:57 ` Marco Elver
2021-02-01 19:43 ` [PATCH 04/12] kasan: clean up setting free info in kasan_slab_free Andrey Konovalov
2021-02-02 17:03 ` Marco Elver
2021-02-01 19:43 ` [PATCH 05/12] kasan: unify large kfree checks Andrey Konovalov
2021-02-03 12:13 ` Marco Elver
2021-02-01 19:43 ` [PATCH 06/12] kasan: rework krealloc tests Andrey Konovalov
2021-02-03 14:48 ` Marco Elver [this message]
2021-02-01 19:43 ` [PATCH 07/12] kasan, mm: remove krealloc side-effect Andrey Konovalov
2021-02-03 15:10 ` Marco Elver
2021-02-01 19:43 ` [PATCH 08/12] kasan, mm: optimize krealloc poisoning Andrey Konovalov
2021-02-03 14:34 ` Marco Elver
2021-02-01 19:43 ` [PATCH 09/12] kasan: ensure poisoning size alignment Andrey Konovalov
2021-02-03 15:31 ` Marco Elver
2021-02-01 19:43 ` [PATCH 10/12] arm64: kasan: simplify and inline MTE functions Andrey Konovalov
2021-02-01 22:44 ` Andrew Morton
2021-02-04 12:39 ` Vincenzo Frascino
2021-02-02 15:42 ` Catalin Marinas
2021-02-02 18:04 ` Andrey Konovalov
2021-02-04 12:37 ` Vincenzo Frascino
2021-02-01 19:43 ` [PATCH 11/12] kasan: always inline HW_TAGS helper functions Andrey Konovalov
2021-02-03 15:51 ` Marco Elver
2021-02-01 19:43 ` [PATCH 12/12] arm64: kasan: export MTE symbols for KASAN tests Andrey Konovalov
2021-02-02 10:46 ` Will Deacon
2021-02-02 13:42 ` Andrey Konovalov
2021-02-02 15:43 ` Catalin Marinas
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