Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751855AbaKKSW1 (ORCPT ); Tue, 11 Nov 2014 13:22:27 -0500 Received: from dehamd003.servertools24.de ([31.47.254.18]:34516 "EHLO dehamd003.servertools24.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089AbaKKSW0 (ORCPT ); Tue, 11 Nov 2014 13:22:26 -0500 Message-ID: <546253D2.9050400@ladisch.de> Date: Tue, 11 Nov 2014 19:22:10 +0100 From: Clemens Ladisch User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Stefan Richter , linux1394-devel@lists.sourceforge.net CC: linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, David Ramos Subject: Re: [PATCH RFC v1b] firewire: cdev: prevent kernel stack leaking into ioctl arguments References: <55D28623-C1C7-47D2-9638-0B8FD0733C48@stanford.edu> <20141111010340.3329bbd7@kant> <20141111130143.2ff3d42e@kant> <20141111171356.2fc62440@kant> <20141111171644.7f6b17c7@kant> In-Reply-To: <20141111171644.7f6b17c7@kant> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-PPP-Message-ID: <20141111182104.924270.18534@dehamd003.servertools24.de> X-PPP-Vhost: ladisch.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Stefan Richter wrote: > This fix simply always null-initializes the entire ioctl argument buffer > regardless of the actual length of expected user input. That is, a > runtime overhead of memset(..., 40) is added to each firewirew-cdev > ioctl() call. This part of the stack is most likely to be already in the cache. Regards, Clemens -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/