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=unavailable 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 613DBC433EF for ; Fri, 10 Sep 2021 00:57:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4190461186 for ; Fri, 10 Sep 2021 00:57:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235368AbhIJA6p (ORCPT ); Thu, 9 Sep 2021 20:58:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:48462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234109AbhIJAWw (ORCPT ); Thu, 9 Sep 2021 20:22:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BF08F60F24; Fri, 10 Sep 2021 00:21:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631233301; bh=0hqLhf3xDeqnlEfMl0vTqr15V4Eg04LXNoz6C5tPcGw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YVDH9aWKaxZr5a9wibqWwUP5W8f1v7vt5GsOXneuax3Hus9E+LzUy+tRXbieL7HYB 7DoWsy2p88ARFprlMd9ZaCNdrUM9GfaZoWsQyuhnJ9E3r9Q3GEiv6TAukyz8cvr+a3 QWVUE0edFq39t0MBawqeRiz6smFaodWb7bOHVIGuXpqEFMzupbz6rO6XR4Xp4ghMLj xsGCo6RpMyIV0fyXIpFeNDtDfW7/JZmvedetWvaKNXM9+q0rEQWJ+kGP6eUJv64Q2C Lpl80t1DtuXiPu9Urz5u/c6u7OWNsGPV2zNOr96C0OM/7ogiQhLkO9ZrkNPkDRGohf Z7NXeaYe48TbA== 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 5.10 53/53] kasan: test: avoid corrupting memory in kasan_rcu_uaf Date: Thu, 9 Sep 2021 20:20:28 -0400 Message-Id: <20210910002028.175174-53-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210910002028.175174-1-sashal@kernel.org> References: <20210910002028.175174-1-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: linux-kernel@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 2d68db6ae67b..1c6e06136f78 100644 --- a/lib/test_kasan_module.c +++ b/lib/test_kasan_module.c @@ -73,7 +73,7 @@ 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