Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754614AbYGALVV (ORCPT ); Tue, 1 Jul 2008 07:21:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752411AbYGALVG (ORCPT ); Tue, 1 Jul 2008 07:21:06 -0400 Received: from relay.2ka.mipt.ru ([194.85.82.65]:44673 "EHLO 2ka.mipt.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbYGALVE (ORCPT ); Tue, 1 Jul 2008 07:21:04 -0400 Date: Tue, 1 Jul 2008 15:21:06 +0400 From: Evgeniy Polyakov To: Vegard Nossum Cc: netdev@vger.kernel.org, Pekka Enberg , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: kmemcheck detected possible information leak to userspace? Message-ID: <20080701112106.GB17015@2ka.mipt.ru> References: <19f34abd0807010216k11a60382xf7a27b4b27f0819@mail.gmail.com> <20080701102459.GB30248@2ka.mipt.ru> <19f34abd0807010352t264fda16g826912a857e88140@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <19f34abd0807010352t264fda16g826912a857e88140@mail.gmail.com> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 826 Lines: 20 On Tue, Jul 01, 2008 at 12:52:53PM +0200, Vegard Nossum (vegard.nossum@gmail.com) wrote: > The u means uninitialized. So it seems not to be just the end. But I > am not sure where the end of the buffer is anyway. > > But there is one thing I forgot: Is this memory initialized by DMA? If > so, the warning is bogus and I will go hide in shame. It depends on driver, but sufficiently new hardware (or better say any non-crappy hardware) will do dma transafer just into skb->data. To catch it you can put kmemcheck hooks into pci_map* and friend functions. -- Evgeniy Polyakov -- 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/