Received: by 2002:ac0:8c9a:0:0:0:0:0 with SMTP id r26csp5395169ima; Tue, 5 Feb 2019 11:02:05 -0800 (PST) X-Google-Smtp-Source: AHgI3IbpvsKtO5Q2LT6Su4j5TIwfvXWRNtbvXekpNLNJaibMSyQnxaGZ8VaYJkps+7y+qHBadkpa X-Received: by 2002:a63:1a4b:: with SMTP id a11mr5885091pgm.254.1549393325495; Tue, 05 Feb 2019 11:02:05 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1549393325; cv=none; d=google.com; s=arc-20160816; b=Hu+xHgQuzS6DsRDdrvE5BIqMfSiau7CPyBYyZ+UzCo4iAphBiLVaZTA8E6e4Yo+epw gw/qFGtP9fotgd5VyXPcHVMpWqI6ERAH4vQ0iKS3bs3x7KN0Lx9dQpkEMMdXBtQ1HWpf XmN/njLnpsIjdCSePSg8V25P6bUUs2nT3us3XQ2DCzTZI3w4GKiplrKs+TD9tBtFKYa2 07ZYJuBISdCHHHf91KgIjvs1Onkh3nxe1pc1+3MHias0s3JvZQvxbKlZWtxFDYnXbYKS 4dvlcd5iW2wwk65QA0Pmb5BEC8IwnN2idHJCTgNWwy85hGSmIG47OvdSjqleOQBImuPC CJLw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:dkim-signature; bh=cuDQcjUbCi+3udHUF0f6uihAI6L2Di+CjBfeDHh1WXk=; b=Z+qKYldkoAMeM7248xSt6MpsGwwAqnDegSDAftwqXtU3AYKF20oHazfyg9/dtTtLPg hSx2A5XihpGmearFxpU+JmwtH4vLpSMO/O6TwF0rbE9Rjx7WP0gjgw9PPpL8tI8nHsnr V953Nik//Zhps5VI9Wjw/3XgMCOEDFGXRLTeOk2Auc2aOjfEEP/Ps79J+KSVY+JLDa9T KXm8YBIEgidmUi0P1w4exQLGAVOuVXTnEU0z+AI8x3WdVf3pqe1//QPe4OyK200js1e3 z/4Uoe7c0OxMWhUtkgzmwn33f8gL91l8TWLzmzQOguS+iw8ZAPdpxcLaD/TxA6/dfYK8 fskA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b="OF/rOfnQ"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id s8si3586737pgm.508.2019.02.05.11.01.49; Tue, 05 Feb 2019 11:02:04 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b="OF/rOfnQ"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730463AbfBESmy (ORCPT + 99 others); Tue, 5 Feb 2019 13:42:54 -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