The patch titled
Subject: kasan: add proper page allocator tests
has been added to the -mm tree. Its filename is
kasan-add-proper-page-allocator-tests.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-add-proper-page-allocator-tests.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-add-proper-page-allocator-tests.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: add proper page allocator tests
The currently existing page allocator tests rely on kmalloc fallback
with large sizes that is only present for SLUB. Add proper tests that
use alloc/free_pages().
Link: https://lkml.kernel.org/r/15ca1976b26aa9edcec4a9d0f3b73f5b6536e5d0.1609871239.git.andreyknvl@xxxxxxxxxx
Link: https://linux-review.googlesource.com/id/Ia173d5a1b215fe6b2548d814ef0f4433cf983570
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: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/test_kasan.c | 54 ++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 49 insertions(+), 5 deletions(-)
--- a/lib/test_kasan.c~kasan-add-proper-page-allocator-tests
+++ a/lib/test_kasan.c
@@ -128,6 +128,12 @@ static void kmalloc_node_oob_right(struc
kfree(ptr);
}
+/*
+ * These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
+ * fit into a slab cache and therefore is allocated via the page allocator
+ * fallback. Since this kind of fallback is only implemented for SLUB, these
+ * tests are limited to that allocator.
+ */
static void kmalloc_pagealloc_oob_right(struct kunit *test)
{
char *ptr;
@@ -138,14 +144,11 @@ static void kmalloc_pagealloc_oob_right(
return;
}
- /*
- * Allocate a chunk that does not fit into a SLUB cache to trigger
- * the page allocator fallback.
- */
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
+
kfree(ptr);
}
@@ -161,8 +164,8 @@ static void kmalloc_pagealloc_uaf(struct
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
-
kfree(ptr);
+
KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
}
@@ -182,6 +185,45 @@ static void kmalloc_pagealloc_invalid_fr
KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
}
+static void pagealloc_oob_right(struct kunit *test)
+{
+ char *ptr;
+ struct page *pages;
+ size_t order = 4;
+ size_t size = (1UL << (PAGE_SHIFT + order));
+
+ /*
+ * With generic KASAN page allocations have no redzones, thus
+ * out-of-bounds detection is not guaranteed.
+ * See https://bugzilla.kernel.org/show_bug.cgi?id=210503.
+ */
+ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) {
+ kunit_info(test, "skipping, CONFIG_KASAN_GENERIC enabled");
+ return;
+ }
+
+ pages = alloc_pages(GFP_KERNEL, order);
+ ptr = page_address(pages);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+
+ KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
+ free_pages((unsigned long)ptr, order);
+}
+
+static void pagealloc_uaf(struct kunit *test)
+{
+ char *ptr;
+ struct page *pages;
+ size_t order = 4;
+
+ pages = alloc_pages(GFP_KERNEL, order);
+ ptr = page_address(pages);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
+ free_pages((unsigned long)ptr, order);
+
+ KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
+}
+
static void kmalloc_large_oob_right(struct kunit *test)
{
char *ptr;
@@ -933,6 +975,8 @@ static struct kunit_case kasan_kunit_tes
KUNIT_CASE(kmalloc_pagealloc_oob_right),
KUNIT_CASE(kmalloc_pagealloc_uaf),
KUNIT_CASE(kmalloc_pagealloc_invalid_free),
+ 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),
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-prefix-exported-functions-with-kasan_.patch
kasan-clarify-hw_tags-impact-on-tbi.patch
kasan-clean-up-comments-in-tests.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-adopt-kmalloc_uaf2-test-to-hw_tags-mode.patch
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
kasan-fix-bug-detection-via-ksize-for-hw_tags-mode.patch
kasan-add-proper-page-allocator-tests.patch
