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=-16.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_MED,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 12294C04AB5 for ; Mon, 3 Jun 2019 16:55:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD40127552 for ; Mon, 3 Jun 2019 16:55:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="URpy1zkC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729617AbfFCQzw (ORCPT ); Mon, 3 Jun 2019 12:55:52 -0400 Received: from mail-ot1-f73.google.com ([209.85.210.73]:38893 "EHLO mail-ot1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727876AbfFCQzu (ORCPT ); Mon, 3 Jun 2019 12:55:50 -0400 Received: by mail-ot1-f73.google.com with SMTP id x23so9223999otp.5 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=CG2SSh0rNgFnkszKdbY/Gdv3en0dpl8hzLzkvkhS1vPeJaXutC5imB+dvfcKrz0nqL CxopZH6bFxHpJj89X2dJrnzaqu1a/7lQHs0K+BVdE8oKkC1+PW5J/XjZqDP8kntQqLNj cul7lZMRYhi9pPLuTyavgodE6IIs8gS37g9B6PR5oe/CEUSxZhK/cFfzbMMvHWn2hl5L ZZFKQ41x5/oY960fWXI8aH0Krf01afRev+z5KejwPwL/nNV0KVs4zFvtcAVK8bYtPJp5 pfyyJEY0XeCNLjgg4aCLfzY6LfU62YR+mZYNHE3plt/x9PACkBFcOlI7hNstg3R8bJ7D NABA== X-Gm-Message-State: APjAAAVAVINIvqdYEB0vsrSguDSoZpRcKrLLpi7irG4LJ6wf9KwUFcHv 5fLItUTxjsX8FmCMx9PE14YmzOLbnwk167xg 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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; -- 2.22.0.rc1.311.g5d7573a151-goog