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=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham 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 AF3BFC282CB for ; Tue, 5 Feb 2019 18:42:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 83D15217D6 for ; Tue, 5 Feb 2019 18:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549392177; bh=/uZJsZQOx7NxlXrfevR1SSxhR1PBFj8ekns+vQF1bWs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=D6HTfFjlCr8PLcagNL1MSqeq8ZNXfAb5GdzaSDrDN1fwqSV8wTfUpo4Iv4YicG/Ym H6XveU2bzSYz/b4i/HzyoJw73m4/fGWTOhtPho+t+XstcSo7z45mFe0q9bP+i+vKt9 zWMLXSEHaBgTVmcpaxW7TyFmIXpPTUrieUxYDEzo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730474AbfBESmz (ORCPT ); Tue, 5 Feb 2019 13:42:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:41628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726731AbfBESmx (ORCPT ); Tue, 5 Feb 2019 13:42:53 -0500 Received: from localhost (unknown [167.98.85.149]) (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 598AC217D6; Tue, 5 Feb 2019 18:42:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549392173; bh=/uZJsZQOx7NxlXrfevR1SSxhR1PBFj8ekns+vQF1bWs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OF/rOfnQHXkkabNVGbZl8XguQTilDlRL3r+rzFAk9sD+6Xej1xyB8kVZCZm3ea1mP fM9bn3s2ARlf2W+ZWvEH81AnYkFZfxosRyQqYYm6/W6M0WuYm9YRUdcVdPVxfOL3hg Mn84v07nB0ALX7T3ovToLO8/xNsJjz1xtf3VLdYA= Date: Tue, 5 Feb 2019 19:42:50 +0100 From: Greg KH To: Kees Cook Cc: Sven Van Asbroeck , Tejun Heo , Lai Jiangshan , LKML , Sebastian Reichel , Dmitry Torokhov Subject: Re: [RFC v1 0/3] Address potential user-after-free on module unload Message-ID: <20190205184250.GB22198@kroah.com> References: <20190204220952.30761-1-TheSven73@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 05, 2019 at 02:57:11PM +0000, Kees Cook wrote: > On Mon, Feb 4, 2019 at 10:09 PM Sven Van Asbroeck wrote: > > > > I think there _might_ be potential use-after-free issues on module unload. There are loads of issues with module unloading, which is why it pretty much is a "best effort" type of thing. It never happens automatically and the only way you can do it is if you have root access, at which point, there are loads of other things you can do that are much worse :) thanks, greg k-h