From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 04F537F37 for ; Wed, 26 Aug 2015 17:56:17 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay2.corp.sgi.com (Postfix) with ESMTP id D2FEC30405F for ; Wed, 26 Aug 2015 15:56:16 -0700 (PDT) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id 4iYVw4QwDnOS4WMs for ; Wed, 26 Aug 2015 15:56:14 -0700 (PDT) Date: Thu, 27 Aug 2015 08:56:01 +1000 From: Dave Chinner Subject: Re: [PATCH V3] xfsdump: prevent segfault in cb_add_inogrp Message-ID: <20150826225601.GG3902@dastard> References: <20150924193241.975348815@gulag1.americas.sgi.com> <77EDF3BA.60409@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <77EDF3BA.60409@sgi.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: rjohnston@sgi.com Cc: xfs@oss.sgi.com On Wed, Aug 26, 2015 at 05:29:55PM -0500, rjohnston@sgi.com wrote: > > The call to memset will segfault because the offset for the first > parameter is done twice. We are using pointer math to do the > calculation. > > The first time is when calculating oldsize, the size of i2gseg_t > is accounted for. > oldsize = (numsegs - SEGPERHNK) * sizeof(i2gseg_t); > Then in the call to memset, oldsize is again multiplied by the size > of i2gmap_t. > memset(inomap.i2gmap + oldsize, ...) > > i2gmap holds the used inodes in each chunk. When there are 2^31 chunk > entries, it could describe 2^31 (1 inode/chunk)- 2^40 (64 inodes/chunk). > > With 100s of millions of inodes there are enough entries to wrap the > 32 bit variable oldsize. > > Adding a bounds check (numsegs < 0) and switching to use array > index notation instead of calculating the pointer address twice > would resolve this issue. The unneeded local variable oldsize > can be removed as well. Can't believe I missed this first two times time through - the patch is missing your signed-off-by. Just reply with it, and I'll fix it up on commit. :) Thanks, Rich! Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs