From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Naujoks Subject: Re: [PATCH stable 3.11+] can: bcm: add skb destructor Date: Wed, 29 Jan 2014 16:35:52 +0100 Message-ID: <52E91FD8.90402@gmail.com> References: <52E833ED.4080006@hartkopp.net> <1390953066.28432.26.camel@edumazet-glaptop2.roam.corp.google.com> <52E8B053.2030808@gmail.com> <20140128.234630.1768378245126172951.davem@davemloft.net> <52E8C03A.4030906@gmail.com> <1391007225.28432.29.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: David Miller , socketcan@hartkopp.net, netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail-wg0-f47.google.com ([74.125.82.47]:45814 "EHLO mail-wg0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751341AbaA2Pfz (ORCPT ); Wed, 29 Jan 2014 10:35:55 -0500 Received: by mail-wg0-f47.google.com with SMTP id m15so3786600wgh.26 for ; Wed, 29 Jan 2014 07:35:54 -0800 (PST) In-Reply-To: <1391007225.28432.29.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: On 29.01.2014 15:53, schrieb Eric Dumazet: > On Wed, 2014-01-29 at 09:47 +0100, Andre Naujoks wrote: >> On 29.01.2014 08:46, schrieb David Miller: >>> From: Andre Naujoks >>> Date: Wed, 29 Jan 2014 08:40:03 +0100 >>> >>>> Even if this is a bug in the CAN BCM implementation. Your "fix" just >>>> enabled a user space application to shut down any machine with a kernel >>>> containing the BUG_ON patch. >>> >>> Rather, he detected a potential stray pointer reference to freed data >>> that was caused by the CAN code which would difficult if not >>> impossible to detect otherwise. >>> >>> That's even more dangerous, and you should be thanking him. >> >> "potential" is the keyword here. But its a definite kernel crash as it >> is right now with a standard use case for the BCM. >> >> Don't get me wrong. If there are bugs in the code, they should be fixed, >> but I don't think breaking a working (even if flawed) part of the kernel >> is the right thing to do here. > > Shall I remember you this patch was suggested by David Miller, our > beloved network maintainer ? no, but thank you. > > Really this is quite silly, I'll tell you. Totally with you on that. > > I can send a patch to mark CAN as BROKEN if you want, or you can send an > appropriate patch. > > Your resistance is futile. I am not resisting to anything. I was just *irritated* about the way this was handled. Since Oliver is already trying to fix this, any further discussion here is meaningless anyway. Regards Andre > >