From patchwork Wed Aug 11 19:21:17 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: 12431821 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 7E48CC4320A for ; Wed, 11 Aug 2021 19:21:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 03E2760F35 for ; Wed, 11 Aug 2021 19:21:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 03E2760F35 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 569316B0071; Wed, 11 Aug 2021 15:21:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4B5236B0078; Wed, 11 Aug 2021 15:21:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 283686B0071; Wed, 11 Aug 2021 15:21:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0199.hostedemail.com [216.40.44.199]) by kanga.kvack.org (Postfix) with ESMTP id 05DA56B0072 for ; Wed, 11 Aug 2021 15:21:43 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 99E21181C5C5E for ; Wed, 11 Aug 2021 19:21:43 +0000 (UTC) X-FDA: 78463769286.06.F53ABD3 Received: from out1.migadu.com (out1.migadu.com [91.121.223.63]) by imf05.hostedemail.com (Postfix) with ESMTP id E91FD503B855 for ; Wed, 11 Aug 2021 19:21:42 +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=1628709701; 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=hOF2jU13WMxGXYYEG436TSXwGCcE2aedIoEPoNI5CQoEycB/bVTKm6f5ZmS+2dFlBGDiDx v7t95qegZNw2qvMTS8poe8JntrzUbYka8gmE8QAGtrXSxRHexl9wtstvVbaTsFnWQXAgt0 rwlNza06rHWoAtKW+JVFHbx1Da21aX8= 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 1/8] kasan: test: rework kmalloc_oob_right Date: Wed, 11 Aug 2021 21:21:17 +0200 Message-Id: <474aa8b7b538c6737a4c6d0090350af2e1776bef.1628709663.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 Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=hOF2jU13; spf=pass (imf05.hostedemail.com: domain of andrey.konovalov@linux.dev designates 91.121.223.63 as permitted sender) smtp.mailfrom=andrey.konovalov@linux.dev; dmarc=pass (policy=none) header.from=linux.dev X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: E91FD503B855 X-Stat-Signature: mcm7dkcz4a4eda1ryiizynaxrdusx4bc X-HE-Tag: 1628709702-925786 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 Reviewed-by: Marco Elver --- 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); }