Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   andrey.konovalov@linux.dev
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Marco Elver <elver@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Alexander Potapenko <glider@google.com>,
        kasan-dev@googlegroups.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/8] kasan: test: disable kmalloc_memmove_invalid_size for HW_TAGS
Date:   Thu, 12 Aug 2021 16:53:31 +0200
Message-Id: <088733a06ac21eba29aa85b6f769d2abd74f9638.1628779805.git.andreyknvl@gmail.com>
In-Reply-To: <cover.1628779805.git.andreyknvl@gmail.com>
References: <cover.1628779805.git.andreyknvl@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Andrey Konovalov <andreyknvl@gmail.com>

The HW_TAGS mode doesn't check memmove for negative size. As a result,
the kmalloc_memmove_invalid_size test corrupts memory, which can result
in a crash.

Disable this test with HW_TAGS KASAN.

Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
---
 lib/test_kasan.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index db73bc9e3fa2..1f533a7346d9 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -501,11 +501,17 @@ static void kmalloc_memmove_invalid_size(struct kunit *test)
 	size_t size = 64;
 	volatile size_t invalid_size = -2;
 
+	/*
+	 * Hardware tag-based mode doesn't check memmove for negative size.
+	 * As a result, this test introduces a side-effect memory corruption,
+	 * which can result in a crash.
+	 */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
+
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
 	memset((char *)ptr, 0, 64);
-
 	KUNIT_EXPECT_KASAN_FAIL(test,
 		memmove((char *)ptr, (char *)ptr + 4, invalid_size));
 	kfree(ptr);
-- 
2.25.1