From mboxrd@z Thu Jan 1 00:00:00 1970 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 78813C4338F for ; Thu, 12 Aug 2021 15:05:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 599AC610A3 for ; Thu, 12 Aug 2021 15:05:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238313AbhHLPGP (ORCPT ); Thu, 12 Aug 2021 11:06:15 -0400 Received: from out1.migadu.com ([91.121.223.63]:30844 "EHLO out1.migadu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234850AbhHLPGO (ORCPT ); Thu, 12 Aug 2021 11:06:14 -0400 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=1628780748; 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=QSI/+PvPlE003ZXaIEqU/DOlYJI1rrLbLbUubnyaViGSpo+8aAep5PhhqhhoBSDWxq8+b3 vbAI5SHLL5NIic42TlY3BI2I1Wm0p6LKwx869q3DoOGai632ePiZX6cfuaRjXRpU6WDRah TSFmj37nTZtZ21WJ1XFqjFhjkjgWlk0= 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 8/8] kasan: test: avoid corrupting memory in kasan_rcu_uaf Date: Thu, 12 Aug 2021 17:05:46 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: andrey.konovalov@linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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) -- 2.25.1