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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 645CFC433F5 for ; Fri, 10 Sep 2021 00:44:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5048761108 for ; Fri, 10 Sep 2021 00:44:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241857AbhIJApp (ORCPT ); Thu, 9 Sep 2021 20:45:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:47404 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233321AbhIJAVg (ORCPT ); Thu, 9 Sep 2021 20:21:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8136F610E9; Fri, 10 Sep 2021 00:20:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233226; bh=dcMN18hCQ+HoYY7mN0kEg/7owgCb7/zijP7JEOL6MuU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IRb+cZnBpw8kG1GD8vMmNXFnoqso+l7EO4NDb3MAwl5pTVJYnGhMK7X0vK2uOb1C/ OuWh/h/lKXhehh5IsB3lN2YYmci2mTxRmMvPDUEuQ/Kl4qcaK/TOZDyN8l2ei0A6Nv ScEKnTJ9/zXmMq5NL7BZSw565eN5IhIib3CPA+hOsAl7HJU/V9tEAEfU6QP6MvGGVe QqUhRmQuvJGX95HROxt6W57GYbaqoVR/bYYhekXmj7YTmDU9TCSsaDYNBSTX5QK8xN B5VWJdgOx6T7vs/mCTP+BQG7/pBMZh4y/mOF9x4/ljglUnGht1cd0fxmgujoHZDLaP s6jLLxmyavJPA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Andrey Ryabinin , Dmitry Vyukov , Andrew Morton , Linus Torvalds , Sasha Levin , kasan-dev@googlegroups.com Subject: [PATCH AUTOSEL 5.13 88/88] kasan: test: avoid corrupting memory in kasan_rcu_uaf Date: Thu, 9 Sep 2021 20:18:20 -0400 Message-Id: <20210910001820.174272-88-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910001820.174272-1-sashal@kernel.org> References: <20210910001820.174272-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrey Konovalov [ Upstream commit f16de0bcdb55bf18e2533ca625f3e4b4952f254c ] 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. Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- 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) -- 2.30.2