From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933515AbbDVGdM (ORCPT ); Wed, 22 Apr 2015 02:33:12 -0400 Received: from mail.emea.novell.com ([130.57.118.101]:58766 "EHLO mail.emea.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933440AbbDVGdJ convert rfc822-to-8bit (ORCPT ); Wed, 22 Apr 2015 02:33:09 -0400 Message-Id: <55375CC30200007800074A08@mail.emea.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.0.1 Date: Wed, 22 Apr 2015 07:33:07 +0100 From: "Jan Beulich" To: "Linus Torvalds" Cc: Subject: regression from your recent change to x86's copy_user_handle_tail() Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, while the description of commit cae2a173fe certainly makes sense, the change itself ignores the __probe_kernel_write() code path, for which the destination address is expected to be in kernel space but accesses may still fault. I.e. the use of plain memset() causes __probe_kernel_write() to oops rather than return an error. Shouldn't the "(unsigned long)to >= TASK_SIZE_MAX" be relaxed to take the effect of set_fs() into account? Thanks, Jan