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@xxxxxxxxxx>
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@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Acked-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx are
kasan-fix-array-bounds-warnings-in-tests.patch
