From patchwork Wed Aug 11 19:34:00 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: 12431839 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 D1061C4320A for ; Wed, 11 Aug 2021 19:34:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6F66661008 for ; Wed, 11 Aug 2021 19:34:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F66661008 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 D246B6B0071; Wed, 11 Aug 2021 15:34:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id CD4F96B0072; Wed, 11 Aug 2021 15:34:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BC3FC6B0073; Wed, 11 Aug 2021 15:34:06 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0003.hostedemail.com [216.40.44.3]) by kanga.kvack.org (Postfix) with ESMTP id 9EE5D6B0071 for ; Wed, 11 Aug 2021 15:34:06 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 4F81418022BFF for ; Wed, 11 Aug 2021 19:34:06 +0000 (UTC) X-FDA: 78463800492.04.28C657B Received: from out1.migadu.com (out1.migadu.com [91.121.223.63]) by imf04.hostedemail.com (Postfix) with ESMTP id F1AD55004A04 for ; Wed, 11 Aug 2021 19:34:03 +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=1628710442; 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=ikZnRm2MVtJHm0Ia+fXtL9BHvKn2N23olNLH7huqioo=; b=gLxXIwemBjQyLG6H9gnaaiLf4noXa4CpUotGNEpTCNeDc+YIsb3ZUKCDdyrbZIwh+d17/k di/+fVQOTW/CUtH/7mP5M2cl879hHF9yRUx9absN4HBAz8+DQm5BPcIALMg4YU8IJEeUtD Q29ZB92XMCPsehZlG2fCGFYEv4PZ7FE= 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 8/8] kasan: test: avoid corrupting memory in kasan_rcu_uaf Date: Wed, 11 Aug 2021 21:34:00 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=gLxXIwem; spf=pass (imf04.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: F1AD55004A04 X-Stat-Signature: j3kuszdm6uftsnski4zmc44itb9styyi X-HE-Tag: 1628710443-196040 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 kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is only safe with the GENERIC mode (as it uses quarantine). For other modes, this test corrupts kernel memory, which might result in a crash. Turn the write into a read. Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver --- lib/test_kasan_module.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c index fa73b9df0be4..7ebf433edef3 100644 --- a/lib/test_kasan_module.c +++ b/lib/test_kasan_module.c @@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp) struct kasan_rcu_info, rcu); kfree(fp); - fp->i = 1; + ((volatile struct kasan_rcu_info *)fp)->i; } static noinline void __init kasan_rcu_uaf(void)