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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 7A067C43613 for ; Wed, 19 Jun 2019 20:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5499D2082C for ; Wed, 19 Jun 2019 20:02:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="tQKRrCMR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726244AbfFSUCZ (ORCPT ); Wed, 19 Jun 2019 16:02:25 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:36286 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726143AbfFSUCY (ORCPT ); Wed, 19 Jun 2019 16:02:24 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5JJxCMh013084; Wed, 19 Jun 2019 20:01:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=Vroyiiy2apNH9g1WQULlt3tAhqXh3qFzkC0thjbI/tY=; b=tQKRrCMRIZFf76xHdG+OcQRJVCixkQdbl3HfJkhqJ6zQ5Fq71mORMALE81hvlqMU5cq2 K4F8SUycLHKVrHTiluUHLfebVsFtIV4u7NZst1BEEOGeJtKDYGfPNuGNBzsiq/6/sG1m oHmWEWnqBcx8EHxc8VsLy1BXGGOzd4qHtZgUM3+RorIGLB7LeM8SEKQOzG7hpzi3tUIX cBqz1T+7bPFIBDeruJWhgHUJUNTS7jmoeogb9Jt64Fnvc0VzloFKzLKS2q+3tVxVQSnx bLlYN2Mg5EBeENllw30HSTJNHEAnYlsgKqvHUrkE60SZa/hI/hGzXCuuUFok8MhRdXuP yg== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 2t7809ddd7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Jun 2019 20:01:33 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5JK0U82055051; Wed, 19 Jun 2019 20:01:32 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3020.oracle.com with ESMTP id 2t77yp1s13-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Jun 2019 20:01:32 +0000 Received: from abhmp0014.oracle.com (abhmp0014.oracle.com [141.146.116.20]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x5JK1P5e025354; Wed, 19 Jun 2019 20:01:25 GMT Received: from [10.65.164.174] (/10.65.164.174) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 19 Jun 2019 13:01:25 -0700 Subject: Re: [PATCH v17 07/15] fs, arm64: untag user pointers in copy_mount_options To: Andrey Konovalov , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Kevin Brodsky , Szabolcs Nagy References: <4ed871e14cc265a519c6ba8660a1827844371791.1560339705.git.andreyknvl@google.com> From: Khalid Aziz Organization: Oracle Corp Message-ID: <14e49054-01dc-dab5-40cc-71434ea3852a@oracle.com> Date: Wed, 19 Jun 2019 14:01:22 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <4ed871e14cc265a519c6ba8660a1827844371791.1560339705.git.andreyknvl@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9293 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906190164 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9293 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906190164 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org On 6/12/19 5:43 AM, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow= to > pass tagged user pointers (with the top byte set to something else othe= r > than 0x00) as syscall arguments. >=20 > In copy_mount_options a user address is being subtracted from TASK_SIZE= =2E > If the address is lower than TASK_SIZE, the size is calculated to not > allow the exact_copy_from_user() call to cross TASK_SIZE boundary. > However if the address is tagged, then the size will be calculated > incorrectly. >=20 > Untag the address before subtracting. >=20 > Reviewed-by: Kees Cook > Reviewed-by: Catalin Marinas > Signed-off-by: Andrey Konovalov > --- Please update commit log to make it not arm64 specific since this change affects other architectures as well. Other than that, Reviewed-by: Khalid Aziz > fs/namespace.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/fs/namespace.c b/fs/namespace.c > index b26778bdc236..2e85712a19ed 100644 > --- a/fs/namespace.c > +++ b/fs/namespace.c > @@ -2993,7 +2993,7 @@ void *copy_mount_options(const void __user * data= ) > * the remainder of the page. > */ > /* copy_from_user cannot cross TASK_SIZE ! */ > - size =3D TASK_SIZE - (unsigned long)data; > + size =3D TASK_SIZE - (unsigned long)untagged_addr(data); > if (size > PAGE_SIZE) > size =3D PAGE_SIZE; > =20 >=20