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kasan-add-another-use-after-free-test.patch removed from -mm tree

merged mm-stable Andrew Morton 1 participant 1 message Oct 3, 2022

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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 <[email protected]>
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 open here
Signed-off-by Andrey Konovalov <[email protected]>
Acked-by Marco Elver <[email protected]>
Cc Alexander Potapenko <[email protected]>
Cc Andrey Ryabinin <[email protected]>
Cc Dmitry Vyukov <[email protected]>
Cc Evgenii Stepanov <[email protected]>
Cc Peter Collingbourne <[email protected]>
Signed-off-by Andrew Morton <[email protected]>

---

 lib/test_kasan.c |   24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
lib/test_kasan.c renamed from lib/test_kasan.c~kasan-add-another-use-after-free-test +24 -0
@@ -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 [email protected] are

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