From patchwork Mon Jun 3 16:55:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10973295 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 07B5B6C5 for ; Mon, 3 Jun 2019 16:55:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E869128741 for ; Mon, 3 Jun 2019 16:55:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DBD1C28746; Mon, 3 Jun 2019 16:55:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8397728684 for ; Mon, 3 Jun 2019 16:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729598AbfFCQzv (ORCPT ); Mon, 3 Jun 2019 12:55:51 -0400 Received: from mail-ot1-f74.google.com ([209.85.210.74]:49412 "EHLO mail-ot1-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729597AbfFCQzu (ORCPT ); Mon, 3 Jun 2019 12:55:50 -0400 Received: by mail-ot1-f74.google.com with SMTP id l7so3368540otj.16 for ; Mon, 03 Jun 2019 09:55:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=ZBmZ0AJkpI6Le2BTudY9LfSDHiJInTNRilsGVrjkAC4=; b=URpy1zkCsiHDZT4QO7sl51daLEh3EGQ+QBRWhBXCE891aX0bBPmoAKSOA31jx1eR/L lVC6wRB0VJkhYxePvRUt+LMH36W5FFHQFgoa3GPev4OVYVi3rHZ7c3DIf31iffj+WRWq O/UwDncv5Fut/rLbuSahvZjC3AOwYT8i5PrP8W6A3ApbgszBZnpxe6Ijm9sVziVKebM1 iMXDrWTNGRgrpGSzVkD4uXSftJythbi88SDUBif5NioLplX3HzpUrRyFyzSWH4dNAKRr WMIQ2F6id96lYcVo97o9s2zuDCTDHymNEv75yNnQamJ6cKIMShowZNQgGMTsd3D7DLBr FGuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=ZBmZ0AJkpI6Le2BTudY9LfSDHiJInTNRilsGVrjkAC4=; b=qAeAd87Ht+BSeVeqHijNEimjHTUdhQ625BOcCRqFbb5e5jKnZbSlyY+4lZEeu1du0c xKK+VeB4V9oz+AqSu6qPH3nRzGHiKfvQXgVqXYyowgenuWIdCG8Zx5DXdjLTOmqDsP2F gf0gQiNFSkh4TA+tlksP2DXOCan8wup8Ld0EL/GPmUY/7pyIMCKKll+YWGhcjAxxg1oy 38zSbZbyjNWVbpxrizJ1UjgJNMJVgpmS4CvGTtyNG4C5+M6jMOU8YB3o07mtmpUXrZj4 mt0BtROpe5VXDxTna/ZoHi9YUGho3oyP7ImNGy9XSLo7MyRFky1attd+SzElXHeekDxE YbhA== X-Gm-Message-State: APjAAAWwikyeRzeS7EWf9mr8M3hUVngcXiut7PWv2vwUNHgKBlHrfFF3 /F+7mAPCGP55Iu4mKdxTxoLUJpGKp3LKhe2N X-Google-Smtp-Source: APXvYqy+jD2zPLosNFGdbJ9ezUNMRGpcmbF5VcOnmGNGlPs/hbYWUHg1PJfAxR5NSiop2ABNMtv5Bkf3tC6COzAd X-Received: by 2002:aca:4c3:: with SMTP id 186mr1626180oie.12.1559580949610; Mon, 03 Jun 2019 09:55:49 -0700 (PDT) Date: Mon, 3 Jun 2019 18:55:10 +0200 In-Reply-To: Message-Id: <51f44a12c4e81c9edea8dcd268f820f5d1fad87c.1559580831.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.rc1.311.g5d7573a151-goog Subject: [PATCH v16 08/16] fs, arm64: untag user pointers in copy_mount_options From: Andrey Konovalov To: 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 , Khalid Aziz , 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 , Andrey Konovalov Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 other than 0x00) as syscall arguments. In copy_mount_options a user address is being subtracted from TASK_SIZE. 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. Untag the address before subtracting. Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov Reviewed-by: Kees Cook --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 = TASK_SIZE - (unsigned long)data; + size = TASK_SIZE - (unsigned long)untagged_addr(data); if (size > PAGE_SIZE) size = PAGE_SIZE;