Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759342AbXJaQGO (ORCPT ); Wed, 31 Oct 2007 12:06:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756115AbXJaQF6 (ORCPT ); Wed, 31 Oct 2007 12:05:58 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:56238 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755295AbXJaQF5 (ORCPT ); Wed, 31 Oct 2007 12:05:57 -0400 Message-ID: <4728A7D4.8050008@garzik.org> Date: Wed, 31 Oct 2007 12:05:40 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.5 (X11/20070727) MIME-Version: 1.0 To: Jens Axboe CC: Alan Cox , Daniel Drake , linux list , linux-ide@vger.kernel.org Subject: Re: "Fix ATAPI transfer lengths" causes CD writing regression References: <47274A5F.6070409@gentoo.org> <20071030153417.59b9182c@the-village.bc.nu> <47276DCA.1000808@gentoo.org> <20071030190153.373c9347@the-village.bc.nu> <47278439.4030801@gentoo.org> <20071031114958.210bd7cc@the-village.bc.nu> <20071031115754.GK5059@kernel.dk> <472872F6.70802@garzik.org> <20071031122639.GN5059@kernel.dk> In-Reply-To: <20071031122639.GN5059@kernel.dk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.1.9 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1144 Lines: 32 Jens Axboe wrote: > Right, that's of course problematic... There has to be a way to recover > that situation though, or you can't export any user command issue > facility. You cannot hope to handle all possible effects arising from an app providing an invalid sg header / cdb. Once you start talking "recovery" you are already screwed: we are talking about low-level hardware commands that are passed straight to the hardware. It is trivial to lock up hardware, brick hardware, and corrupt data at that level. If this is NOT a privileged app, we must update the command validation to ensure that invalid commands are not transported to the hardware. If this is a privileged app, our work is done. Fix the app. We gave root rope, and he took it. I even venture to say that "accept anything, clean up afterwards" is /impossible/ to implement, in addition to being dangerous. Jeff - 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/