From patchwork Thu Aug 12 14:53:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: andrey.konovalov@linux.dev X-Patchwork-Id: 12433733 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D753CC4338F for ; Thu, 12 Aug 2021 14:54:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 73F696108C for ; Thu, 12 Aug 2021 14:54:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 73F696108C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.dev Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 3A2CE8D0006; Thu, 12 Aug 2021 10:53:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 01BCF8D0001; Thu, 12 Aug 2021 10:53:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D88A88D0006; Thu, 12 Aug 2021 10:53:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0231.hostedemail.com [216.40.44.231]) by kanga.kvack.org (Postfix) with ESMTP id 9FC788D0007 for ; Thu, 12 Aug 2021 10:53:54 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 4E1FD82499A8 for ; Thu, 12 Aug 2021 14:53:54 +0000 (UTC) X-FDA: 78466723188.26.999A6E0 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by imf29.hostedemail.com (Postfix) with ESMTP id 76FFA9013A7D for ; Thu, 12 Aug 2021 14:53:53 +0000 (UTC) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1628780031; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=hJvl0j61Zq+oSt6HYk9qiIcFyGt4nhGk7HpIREtRZqk=; b=JwmPAbtUb5XmR/gj7ZWfs+KA7FiPq4mvzQRZXnX5BPUygrXO2nZX5gNY+K6Hmml+//Uyd3 KDr9vab4YxrGHJ2qdhbFheEYpVMz4cPFJl482p/w1QkzK5UMSnr1mgfTKqJvioNqqJUt7R tZ4LSm+3Ryu+6Us1ug9CabRU4LEqeQ8= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Andrey Ryabinin , Marco Elver , Dmitry Vyukov , Alexander Potapenko , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/8] kasan: test: rework kmalloc_oob_right Date: Thu, 12 Aug 2021 16:53:28 +0200 Message-Id: <474aa8b7b538c6737a4c6d0090350af2e1776bef.1628779805.git.andreyknvl@gmail.com> In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 76FFA9013A7D X-Stat-Signature: ynpfe8b3apb9kreko9itcq5oeqe1jtme Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=JwmPAbtU; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf29.hostedemail.com: domain of andrey.konovalov@linux.dev designates 188.165.223.204 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev X-HE-Tag: 1628780033-911895 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Andrey Konovalov Rework kmalloc_oob_right() to do these bad access checks: 1. An unaligned access one byte past the requested kmalloc size (can only be detected by KASAN_GENERIC). 2. An aligned access into the first out-of-bounds granule that falls within the aligned kmalloc object. 3. Out-of-bounds access past the aligned kmalloc object. Test #3 deliberately uses a read access to avoid corrupting memory. Otherwise, this test might lead to crashes with the HW_TAGS mode, as it neither uses quarantine nor redzones. Signed-off-by: Andrey Konovalov --- lib/test_kasan.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 8f7b0b2f6e11..1bc3cdd2957f 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -122,12 +122,28 @@ static void kasan_test_exit(struct kunit *test) static void kmalloc_oob_right(struct kunit *test) { char *ptr; - size_t size = 123; + size_t size = 128 - KASAN_GRANULE_SIZE - 5; ptr = kmalloc(size, GFP_KERNEL); KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr); - KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 'x'); + /* + * An unaligned access past the requested kmalloc size. + * Only generic KASAN can precisely detect these. + */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x'); + + /* + * An aligned access into the first out-of-bounds granule that falls + * within the aligned kmalloc object. + */ + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y'); + + /* Out-of-bounds access past the aligned kmalloc object. */ + KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = + ptr[size + KASAN_GRANULE_SIZE + 5]); + kfree(ptr); }