Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765309AbcLVGaw (ORCPT ); Thu, 22 Dec 2016 01:30:52 -0500 Received: from ipmail04.adl6.internode.on.net ([150.101.137.141]:33684 "EHLO ipmail04.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750792AbcLVGau (ORCPT ); Thu, 22 Dec 2016 01:30:50 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2BOGwB7cltYIOyiLHleGgEBAQECAQEBAQgBAQEBgzUBAQEBAR9cgQiCfotFlDYBAQEBAQeBHIw3hA+GVx8LhXIEAgKBYFQBAgEBAQEBAgYBAQEBAQE5RYRpAQEEASYTHCMQCAMOCgklDwUUEQMHGhOIXwwPqko8iwABAQgCJiCFU4UcgT0BgnCFcwWad4xChGqQXkmNW4QPgV0WDYQWDQ8YgVkqNIhaAQEB Date: Thu, 22 Dec 2016 17:30:46 +1100 From: Dave Chinner To: Christoph Hellwig Cc: Linus Torvalds , Chris Leech , Linux Kernel Mailing List , Lee Duncan , open-iscsi@googlegroups.com, Linux SCSI List , linux-block@vger.kernel.org Subject: Re: [4.10, panic, regression] iscsi: null pointer deref at iscsi_tcp_segment_done+0x20d/0x2e0 Message-ID: <20161222063046.GH4758@dastard> References: <20161214222411.GH4326@dastard> <20161214222953.GI4326@dastard> <20161216185906.t2wmrr6wqjdsrduw@straylight.hirudinean.org> <20161221221638.GD4758@dastard> <20161222061827.GA31630@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161222061827.GA31630@lst.de> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 987 Lines: 24 On Thu, Dec 22, 2016 at 07:18:27AM +0100, Christoph Hellwig wrote: > On Wed, Dec 21, 2016 at 03:19:15PM -0800, Linus Torvalds wrote: > > Looking around a bit, the only even halfway suspicious scatterlist > > initialization thing I see is commit f9d03f96b988 ("block: improve > > handling of the magic discard payload") which used to have a magic > > hack wrt !bio->bi_vcnt, and that got removed. See __blk_bios_map_sg(), > > now it does __blk_bvec_map_sg() instead. > > But that check was only for discard (and discard-like) bios which > had the maic single page that sometimes was unused attached. > > For "normal" bios the for_each_segment loop iterates over bi_vcnt, > so it will be ignored anyway. That being said both I and the lists > got CCed halfway through the thread and I haven't seen the original > report, so I'm not really sure what's going on here anyway. http://www.gossamer-threads.com/lists/linux/kernel/2587485 Cheers, Dave. -- Dave Chinner david@fromorbit.com