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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B796C352A1 for ; Wed, 30 Mar 2022 12:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347433AbiC3MGq (ORCPT ); Wed, 30 Mar 2022 08:06:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58162 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345891AbiC3LzI (ORCPT ); Wed, 30 Mar 2022 07:55:08 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DB2425ECB2; Wed, 30 Mar 2022 04:52:10 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D13A061616; Wed, 30 Mar 2022 11:52:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A80F1C3410F; Wed, 30 Mar 2022 11:52:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648641129; bh=F60sn2dNhMzWGLeWPjD2F3i4dvAVumbpwBD0iIpj0VQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MZmF9hpkvx8+YhIxHHcJ08Xh1Pp4ZOKWNhZY0BXhZAAeb55HaWmIBG6Ta6alEc/+X uvCqoYcKrVnxLfh8aBX7t8eHSodhgHspPlxFbn+APTbZffdTwd0w78P4n2y02a5nzt AGe+ZaPNY/KdzlmaO2AjTeB3druJMk2MtLBAiD5IVK/+7c4f6ctCgyo5PwjPxLOGiz CTrOYJYjL7Ypzwb4Y8kP8gjZH3cihYmEM1srB/NJui+szeG+DwI56VlEKjAIYMYtLa JmXhJYBYCOm56oSXa9O+dx3vNN7SnHp4k8mUPV50f8ZwJ/lNz1f/Bp/TkSlWZ+OgvO VB31hv57v426Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Arnd Bergmann , Sasha Levin Subject: [PATCH AUTOSEL 5.10 27/37] lib/test_lockup: fix kernel pointer check for separate address spaces Date: Wed, 30 Mar 2022 07:51:12 -0400 Message-Id: <20220330115122.1671763-27-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220330115122.1671763-1-sashal@kernel.org> References: <20220330115122.1671763-1-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: Arnd Bergmann [ Upstream commit 5a06fcb15b43d1f7bf740c672950122331cb5655 ] test_kernel_ptr() uses access_ok() to figure out if a given address points to user space instead of kernel space. However on architectures that set CONFIG_ALTERNATE_USER_ADDRESS_SPACE, a pointer can be valid for both, and the check always fails because access_ok() returns true. Make the check for user space pointers conditional on the type of address space layout. Signed-off-by: Arnd Bergmann Signed-off-by: Sasha Levin --- lib/test_lockup.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/lib/test_lockup.c b/lib/test_lockup.c index 07f476317187..78a630bbd03d 100644 --- a/lib/test_lockup.c +++ b/lib/test_lockup.c @@ -417,9 +417,14 @@ static bool test_kernel_ptr(unsigned long addr, int size) return false; /* should be at least readable kernel address */ - if (access_ok((void __user *)ptr, 1) || - access_ok((void __user *)ptr + size - 1, 1) || - get_kernel_nofault(buf, ptr) || + if (!IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) && + (access_ok((void __user *)ptr, 1) || + access_ok((void __user *)ptr + size - 1, 1))) { + pr_err("user space ptr invalid in kernel: %#lx\n", addr); + return true; + } + + if (get_kernel_nofault(buf, ptr) || get_kernel_nofault(buf, ptr + size - 1)) { pr_err("invalid kernel ptr: %#lx\n", addr); return true; -- 2.34.1