The patch titled
Subject: kasan: rework krealloc tests
has been added to the -mm tree. Its filename is
kasan-rework-krealloc-tests.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-rework-krealloc-tests.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-rework-krealloc-tests.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: rework krealloc tests
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.
Link: https://lkml.kernel.org/r/995edb531f4f976277d7da9ca8a78a96a2ea356e.1612208222.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan.c | 91 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 81 insertions(+), 10 deletions(-)
--- a/lib/test_kasan.c~kasan-rework-krealloc-tests
+++ a/lib/test_kasan.c
@@ -252,11 +252,14 @@ static void kmalloc_large_oob_right(stru
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(st
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(st
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
+ * 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 {
@@ -977,8 +1046,10 @@ static struct kunit_case kasan_kunit_tes
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),
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-prefix-global-functions-with-kasan_.patch
kasan-clarify-hw_tags-impact-on-tbi.patch
kasan-clean-up-comments-in-tests.patch
kasan-add-macros-to-simplify-checking-test-constraints.patch
kasan-add-match-all-tag-tests.patch
kasan-arm64-allow-using-kunit-tests-with-hw_tags-mode.patch
kasan-rename-config_test_kasan_module.patch
kasan-add-compiler-barriers-to-kunit_expect_kasan_fail.patch
kasan-adapt-kmalloc_uaf2-test-to-hw_tags-mode.patch
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
kasan-move-_ret_ip_-to-inline-wrappers.patch
kasan-fix-bug-detection-via-ksize-for-hw_tags-mode.patch
kasan-add-proper-page-allocator-tests.patch
kasan-add-a-test-for-kmem_cache_alloc-free_bulk.patch
kasan-dont-run-tests-when-kasan-is-not-enabled.patch
kasan-mm-dont-save-alloc-stacks-twice.patch
kasan-mm-optimize-kmalloc-poisoning.patch
kasan-optimize-large-kmalloc-poisoning.patch
kasan-clean-up-setting-free-info-in-kasan_slab_free.patch
kasan-unify-large-kfree-checks.patch
kasan-rework-krealloc-tests.patch
kasan-mm-remove-krealloc-side-effect.patch
kasan-mm-optimize-krealloc-poisoning.patch
kasan-ensure-poisoning-size-alignment.patch
arm64-kasan-simplify-and-inline-mte-functions.patch
kasan-always-inline-hw_tags-helper-functions.patch
arm64-kasan-export-mte-symbols-for-kasan-tests.patch
