From patchwork Wed Feb 16 13:13:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 12748547 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8238DC433EF for ; Wed, 16 Feb 2022 13:18:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0DEBC6B0080; Wed, 16 Feb 2022 08:18:07 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 08DF36B0082; Wed, 16 Feb 2022 08:18:07 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E72486B0085; Wed, 16 Feb 2022 08:18:06 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id D93616B0080 for ; Wed, 16 Feb 2022 08:18:06 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 8E596180B3DEB for ; Wed, 16 Feb 2022 13:18:06 +0000 (UTC) X-FDA: 79148696172.29.A4EDF36 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf30.hostedemail.com (Postfix) with ESMTP id 172F880016 for ; Wed, 16 Feb 2022 13:18:05 +0000 (UTC) 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 63F17616AE; Wed, 16 Feb 2022 13:18:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12440C340F0; Wed, 16 Feb 2022 13:17:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645017484; bh=VX4KkQyuIR3tQGDR6prM8ou6pbxkhf/vAdqGON90Cm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CHCgfRQJGdosNV1evKFnaA5ei4xJAQnutJJPhJDJedQb8ubdZ/7Y4gbjZfBoHlpfu 02zUcTsVmwftwP3VFFw8cf1xplYfxud05Hq90fcOl+6pChvWJp2VuJGg6f1dhDmeKP 2Ku7d6y9bCG/B7QQIkLEQll/VqhOb3oxvRxpjL7bHiIP7fh7rr3NkfNXH+hMaXbIfa qHFBF3xOTCoSqLhRyub3LajzF4xQe4lV+XRk2zeVmUEYrZWjONVkWPfTimkvr5qUGC VogArIAmhrmBKTIWZOEA4fZwuT8tCTP8ztaTT853tTOy2yqxBDNJ8/RxehDqdkvFhY Yb158iS57sWQQ== From: Arnd Bergmann To: Linus Torvalds , Christoph Hellwig , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, arnd@arndb.de, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, geert@linux-m68k.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, green.hu@gmail.com, dinguyen@kernel.org, shorne@gmail.com, deller@gmx.de, mpe@ellerman.id.au, peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com, hca@linux.ibm.com, dalias@libc.org, davem@davemloft.net, richard@nod.at, x86@kernel.org, jcmvbkbc@gmail.com, ebiederm@xmission.com, akpm@linux-foundation.org, ardb@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org Subject: [PATCH v2 14/18] lib/test_lockup: fix kernel pointer check for separate address spaces Date: Wed, 16 Feb 2022 14:13:28 +0100 Message-Id: <20220216131332.1489939-15-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20220216131332.1489939-1-arnd@kernel.org> References: <20220216131332.1489939-1-arnd@kernel.org> MIME-Version: 1.0 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=CHCgfRQJ; spf=pass (imf30.hostedemail.com: domain of arnd@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=arnd@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam07 X-Rspam-User: X-Rspamd-Queue-Id: 172F880016 X-Stat-Signature: c171sy58omkoaco3zaauyryis369qc9k X-HE-Tag: 1645017485-192540 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: Arnd Bergmann 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 --- 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 6a0f329a794a..c3fd87d6c2dd 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;