From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 8A5F27F37 for ; Wed, 26 Aug 2015 16:38:32 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id 7845C8F8040 for ; Wed, 26 Aug 2015 14:38:32 -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 2RFhKfOSEwCwq9r9 for ; Wed, 26 Aug 2015 14:38:31 -0700 (PDT) Date: Thu, 27 Aug 2015 07:37:47 +1000 From: Dave Chinner Subject: Re: [PATCH V2] xfsdump: prevent segfault in cb_add_inogrp Message-ID: <20150826213746.GC3902@dastard> References: <20150924193241.975348815@gulag1.americas.sgi.com> <55EDF3BA.60409@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <55EDF3BA.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 12:36:42PM -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. > > 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. > > numsegs is used to calculate an array index, change it from a > signed int (intgen_t) to an unsigned (uint32_t). Description does not match code: > - intgen_t numsegs; > - intgen_t oldsize; > + int32_t numsegs; It's still a signed int here. And, really, just a plain old "int" is fine here. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs