[to-be-updated] kasan-adopt-kmalloc_uaf2-test-to-hw_tags-mode.patch removed from -mm tree

[to-be-updated] kasan-adopt-kmalloc_uaf2-test-to-hw_tags-mode.patch removed from -mm tree

[akpm]

The patch titled
     Subject: kasan: adopt kmalloc_uaf2 test to HW_TAGS mode
has been removed from the -mm tree.  Its filename was
     kasan-adopt-kmalloc_uaf2-test-to-hw_tags-mode.patch

This patch was dropped because an updated version will be merged

------------------------------------------------------
From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan: adopt kmalloc_uaf2 test to HW_TAGS mode

In the kmalloc_uaf2() test, the pointers to the two allocated memory
blocks might be the same, and the test will fail. With the software
tag-based mode, the probability of the that happening is 1/254, so it's
hard to observe the failure. For the hardware tag-based mode though,
the probablity is 1/14, which is quite noticable.

Allow up to 4 attempts at generating different tags for the tag-based
modes.

Link: https://lkml.kernel.org/r/9a4f47fe8717b4b249591b307cdd1f26c46dcb82.1609871239.git.andreyknvl@google.com
Link: https://linux-review.googlesource.com/id/Ibfa458ef2804ff465d8eb07434a300bf36388d55Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/test_kasan.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/lib/test_kasan.c~kasan-adopt-kmalloc_uaf2-test-to-hw_tags-mode
+++ a/lib/test_kasan.c
@@ -375,7 +375,9 @@ static void kmalloc_uaf2(struct kunit *t
 {
 	char *ptr1, *ptr2;
 	size_t size = 43;
+	int counter = 0;
 
+again:
 	ptr1 = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
 
@@ -384,6 +386,13 @@ static void kmalloc_uaf2(struct kunit *t
 	ptr2 = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
 
+	/*
+	 * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
+	 * Allow up to 4 attempts at generating different tags.
+	 */
+	if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 4)
+		goto again;
+
 	KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x');
 	KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
 
_

Patches currently in -mm which might be from andreyknvl@google.com are

kasan-fix-hw_tags-boot-parameters.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