From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755072Ab2JBU0t (ORCPT ); Tue, 2 Oct 2012 16:26:49 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:59905 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754229Ab2JBU0r (ORCPT ); Tue, 2 Oct 2012 16:26:47 -0400 Date: Tue, 2 Oct 2012 13:26:43 -0700 From: Kent Overstreet To: Vivek Goyal Cc: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, axboe@kernel.dk, "Martin K. Petersen" , tj@kernel.org Subject: Re: [dm-devel] [PATCH v3 01/26] block: Fix a buffer overrun in bio_integrity_split() Message-ID: <20121002202643.GQ26488@google.com> References: <1348526106-17074-1-git-send-email-koverstreet@google.com> <1348526106-17074-2-git-send-email-koverstreet@google.com> <20121001212336.GA17165@redhat.com> <20121001214241.GE26488@google.com> <20121002140847.GD758@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121002140847.GD758@redhat.com> 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 On Tue, Oct 02, 2012 at 10:08:47AM -0400, Vivek Goyal wrote: > On Mon, Oct 01, 2012 at 02:42:41PM -0700, Kent Overstreet wrote: > > [..] > > Here's the new patch: > > > > > > commit e270c9ca843b5c86d59431b0d7a676b7846946d6 > > Author: Kent Overstreet > > Date: Mon Oct 1 14:41:08 2012 -0700 > > > > block: Fix a buffer overrun in bio_integrity_split() > > > > bio_integrity_split() seemed to be confusing pointers and arrays - > > bip_vec in bio_integrity_payload is an array appended to the end of the > > payload, so the bio_vecs in struct bio_pair need to come immediately > > after the bio_integrity_payload they're for, and there was an assignment > > in bio_integrity_split() that didn't make any sense. > > > > Also, changed bio_integrity_split() to not refer to the bvecs embedded > > in struct bio_pair, in case there's padding between them and > > bip->bip_vec. > > > > Signed-off-by: Kent Overstreet > > CC: Jens Axboe > > CC: Martin K. Petersen > > > > diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c > > index a3f28f3..4ae22a8 100644 > > --- a/fs/bio-integrity.c > > +++ b/fs/bio-integrity.c > > @@ -694,15 +694,12 @@ void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors) > > bp->bio1.bi_integrity = &bp->bip1; > > bp->bio2.bi_integrity = &bp->bip2; > > > > - bp->iv1 = bip->bip_vec[0]; > > - bp->iv2 = bip->bip_vec[0]; > > + *bp->bip1.bip_vec = bip->bip_vec[0]; > > + *bp->bip2.bip_vec = bip->bip_vec[0]; > > I think this is horrible. Why not introduce bvec pointer in bip (like bio), > to cover the case when bvec are not inline. That's... exactly what the next patch in the series does.