[patch 098/173] kasan: add proper page allocator tests
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STALE2052d
REVIEWED: 9 (9M)
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2021-02-24 20:05:59
Also in:
mm-commits
2 review trailers.
From: Andrey Konovalov <redacted> 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://linux-review.googlesource.com/id/Ia173d5a1b215fe6b2548d814ef0f4433cf983570 Link: https://lkml.kernel.org/r/a2648930e55ff75b8e700f2e0d905c2b55a67483.1610733117.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <redacted> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <redacted> Cc: Branislav Rankov <redacted> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <redacted> Cc: Kevin Brodsky <redacted> Cc: Peter Collingbourne <redacted> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <redacted> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- lib/test_kasan.c | 51 ++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 46 insertions(+), 5 deletions(-)
--- a/lib/test_kasan.c~kasan-add-proper-page-allocator-tests
+++ a/lib/test_kasan.c@@ -147,6 +147,12 @@ 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;
@@ -154,14 +160,11 @@ static void kmalloc_pagealloc_oob_right( KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB); - /* - * 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); }
@@ -174,8 +177,8 @@ 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); }
@@ -192,6 +195,42 @@ 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. + */ + KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC); + + 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;
@@ -903,6 +942,8 @@ 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),
_