From patchwork Mon May 6 16:30:55 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10931419 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 1C33C15A6 for ; Mon, 6 May 2019 16:31:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0BFAE287EA for ; Mon, 6 May 2019 16:31:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F348F28847; Mon, 6 May 2019 16:31:37 +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 9D034287EF for ; Mon, 6 May 2019 16:31:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727158AbfEFQbg (ORCPT ); Mon, 6 May 2019 12:31:36 -0400 Received: from mail-qt1-f201.google.com ([209.85.160.201]:55959 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727141AbfEFQbf (ORCPT ); Mon, 6 May 2019 12:31:35 -0400 Received: by mail-qt1-f201.google.com with SMTP id y10so8944557qti.22 for ; Mon, 06 May 2019 09:31:35 -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=RiesdCLpp+R0f3O9XnLGGd6rw9hYPfKFlydZlXAyMMc=; b=Q6QAvdDCFNZuLS9ja3NkrMR3RvJ0S09G7HKj9q0ktYjp11DSu6sbwte4Z+MCgpdXSa OGL0kcCil/ti4co+BeFvhTmmJ7+RXsHFsfK1hhHv1eec6VZbNopqVkjLet50ydoaeiwT XvmlmBaXIzsx1T6Dyaajg7Bz5pq9Axsw6cJNm2DtIdCFs4IeQzb8CYH1eWRXRhTqPi8L 9AZ0ieEA2P7xzH+IK3hHC6FzJl7z9XjQD9wvxFqfvRNHuz4Kvz+PKDcTznem4kO3i/YF 7eAO6TlPEh3PGwlYJ/3xngzxB39JPbQ+aqDHIcDB8TtrzW/euZk2kR1+K4+g3OqdGfdF qJTQ== 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=RiesdCLpp+R0f3O9XnLGGd6rw9hYPfKFlydZlXAyMMc=; b=D0h+TsEHdX+dzL1/as0D2lEyBOa2YcTtOOa/d7gUTuT0ZY9lQYgMgfVAGhGqLOT+dF Oskcu289BchaOwvrdC8fGY+xKUHSVu7TVu2C3iUhr6kxKjt7qVVqCqfgfcelyV/XWeNp ca9V7ISx3FD1Gw39ic2LFwLN2YJ6Ht+FpMm7P8nBisY1aFA1duLeuLIN1SHGRqK/qzBc RiKfVGQ+2ky5ga5wzbkaMRPlt3zSDdnFdPHj6tsWtCVR2soRyvv7HZeHTNbp6/P774RM ZVWFCx2yqfiMowlUc7lQ1wFGEiDMTF/6HSHu+U/NV7SeI7sG5PGv/sqEBcdfdTjffP8Y /Qmg== X-Gm-Message-State: APjAAAWHtUNE8HNydCI9ldt0NzLZz20jCgLlC9Mt4vaZi3t1j5u6aVkD +IAu83cchszAfJOdyP2rSt7HR60x81BMBVW8 X-Google-Smtp-Source: APXvYqxNt6uYI1SB2jQypHitLB3ZO6cfBHn8QWvA0b8eMRqYbeBN0u2XyLJdNX/EJB3bCPY6PcnOySobJPUt2l9F X-Received: by 2002:a37:9ed6:: with SMTP id h205mr2433459qke.152.1557160294772; Mon, 06 May 2019 09:31:34 -0700 (PDT) Date: Mon, 6 May 2019 18:30:55 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH v15 09/17] 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 , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@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. Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index c9cab307fa77..c27e5713bf04 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2825,7 +2825,7 @@ 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;