Date:   Mon, 03 Oct 2022 14:06:26 -0700
To:     mm-commits@vger.kernel.org, ryabinin.a.a@gmail.com, pcc@google.com,
        glider@google.com, eugenis@google.com, elver@google.com,
        dvyukov@google.com, andreyknvl@google.com,
        akpm@linux-foundation.org
From:   Andrew Morton <akpm@linux-foundation.org>
Subject: [merged mm-stable] kasan-add-another-use-after-free-test.patch removed from -mm tree
Message-Id: <20221003210626.BE506C433D6@smtp.kernel.org>
Precedence: bulk
Reply-To: linux-kernel@vger.kernel.org


The quilt patch titled
     Subject: kasan: add another use-after-free test
has been removed from the -mm tree.  Its filename was
     kasan-add-another-use-after-free-test.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Andrey Konovalov <andreyknvl@google.com>
Subject: kasan: add another use-after-free test
Date: Mon, 5 Sep 2022 23:05:49 +0200

Add a new use-after-free test that checks that KASAN detects
use-after-free when another object was allocated in the same slot.

This test is mainly relevant for the tag-based modes, which do not use
quarantine.

Once [1] is resolved, this test can be extended to check that the stack
traces in the report point to the proper kmalloc/kfree calls.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=212203

Link: https://lkml.kernel.org/r/0659cfa15809dd38faa02bc0a59d0b5dbbd81211.1662411800.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/test_kasan.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/lib/test_kasan.c~kasan-add-another-use-after-free-test
+++ a/lib/test_kasan.c
@@ -612,6 +612,29 @@ again:
 	kfree(ptr2);
 }
 
+/*
+ * Check that KASAN detects use-after-free when another object was allocated in
+ * the same slot. Relevant for the tag-based modes, which do not use quarantine.
+ */
+static void kmalloc_uaf3(struct kunit *test)
+{
+	char *ptr1, *ptr2;
+	size_t size = 100;
+
+	/* This test is specifically crafted for tag-based modes. */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
+
+	ptr1 = kmalloc(size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
+	kfree(ptr1);
+
+	ptr2 = kmalloc(size, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
+	kfree(ptr2);
+
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
+}
+
 static void kfree_via_page(struct kunit *test)
 {
 	char *ptr;
@@ -1382,6 +1405,7 @@ static struct kunit_case kasan_kunit_tes
 	KUNIT_CASE(kmalloc_uaf),
 	KUNIT_CASE(kmalloc_uaf_memset),
 	KUNIT_CASE(kmalloc_uaf2),
+	KUNIT_CASE(kmalloc_uaf3),
 	KUNIT_CASE(kfree_via_page),
 	KUNIT_CASE(kfree_via_phys),
 	KUNIT_CASE(kmem_cache_oob),
_

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

kasan-fix-array-bounds-warnings-in-tests.patch