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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 640BDC43381 for ; Thu, 14 Feb 2019 14:44:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 399162229F for ; Thu, 14 Feb 2019 14:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439301AbfBNOov (ORCPT ); Thu, 14 Feb 2019 09:44:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:33254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732362AbfBNOot (ORCPT ); Thu, 14 Feb 2019 09:44:49 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B44B42229F; Thu, 14 Feb 2019 14:44:48 +0000 (UTC) Date: Thu, 14 Feb 2019 09:44:47 -0500 From: Steven Rostedt To: Changbin Du Cc: mingo@redhat.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] kprobe: safely access memory specified by userspace Message-ID: <20190214094447.0adeea8e@gandalf.local.home> In-Reply-To: <20190214141043.3j6upjrfmse75sma@mail.google.com> References: <20190125151051.7381-1-changbin.du@gmail.com> <20190213143638.y54hghilbyastlpo@mail.google.com> <20190213104143.5c390b28@gandalf.local.home> <20190214000522.n7ltwbnjl3kufdsn@mail.google.com> <20190214080418.0f12923f@vmware.local.home> <20190214141043.3j6upjrfmse75sma@mail.google.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 14 Feb 2019 14:10:44 +0000 Changbin Du wrote: > > No I didn't have the fix. I was running an older kernel actually. One > > before commit 9da3f2b74054406f87dff7101a569217ffceb29b was added. > > There's nothing actually wrong with that code, since kprobes is allowed > > to poke at anything. But that commit considers the kernel using copy > > from user to poke kernel address space is a security bug. > > > Glade to know that. And I wonder wether all such cases have been > disclosed. I noticed the uprobe code also uses some usercopy functions. Well, uprobe shouldn't be poking at kernel addresses ;-) -- Steve