From: Andrey Konovalov <andreyknvl@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Dmitry Vyukov <dvyukov@google.com>,
Alexander Potapenko <glider@google.com>,
Marco Elver <elver@google.com>
Cc: 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,
Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH v3 mm 06/13] kasan: rework krealloc tests
Date: Fri, 5 Feb 2021 18:34:40 +0100 [thread overview]
Message-ID: <c707f128a2bb9f2f05185d1eb52192cf179cf4fa.1612546384.git.andreyknvl@google.com> (raw)
In-Reply-To: <cover.1612546384.git.andreyknvl@google.com>
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.
Reviewed-by: Marco Elver <elver@google.com>
Signed-off-by: Andrey Konovalov <andreyknvl@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 d16ec9e66806..ffebad2f0e6e 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -252,11 +252,14 @@ 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);
@@ -264,15 +267,31 @@ 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);
@@ -280,10 +299,60 @@ 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 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_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 {
@@ -977,8 +1046,10 @@ 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:[~2021-02-05 17:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 17:34 [PATCH v3 mm 00/13] kasan: optimizations and fixes for HW_TAGS Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 01/13] kasan, mm: don't save alloc stacks twice Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 02/13] kasan, mm: optimize kmalloc poisoning Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 03/13] kasan: optimize large " Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 04/13] kasan: clean up setting free info in kasan_slab_free Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 05/13] kasan: unify large kfree checks Andrey Konovalov
2021-02-05 17:34 ` Andrey Konovalov [this message]
2021-02-05 17:34 ` [PATCH v3 mm 07/13] kasan, mm: fail krealloc on freed objects Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 08/13] kasan, mm: optimize krealloc poisoning Andrey Konovalov
2021-02-08 10:48 ` Marco Elver
2021-02-09 13:24 ` Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 09/13] kasan: ensure poisoning size alignment Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 10/13] arm64: kasan: simplify and inline MTE functions Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 11/13] kasan: inline HW_TAGS helper functions Andrey Konovalov
2021-02-08 11:04 ` Marco Elver
2021-02-05 17:34 ` [PATCH v3 mm 12/13] arm64: kasan: export MTE symbols for KASAN tests Andrey Konovalov
2021-02-05 17:34 ` [PATCH v3 mm 13/13] kasan: clarify that only first bug is reported in HW_TAGS Andrey Konovalov
2021-02-08 11:06 ` Marco Elver
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