From: Sowmini Varadhan Subject: Re: [PATCH net-next 2/2] xfrm: Fix unaligned access in xfrm_notify_sa() for DELSA Date: Wed, 21 Oct 2015 06:54:42 -0400 Message-ID: <20151021105442.GM6948@oracle.com> References: <65f37efeff5af105c89493dda4f38c61e4cd495f.1445286755.git.sowmini.varadhan@oracle.com> <20151021065704.GM7701@secunet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, herbert@gondor.apana.org.au, dhowells@redhat.com, davem@davemloft.net, zohar@linux.vnet.ibm.com, David.Woodhouse@intel.com To: Steffen Klassert Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:37317 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752334AbbJUKzG (ORCPT ); Wed, 21 Oct 2015 06:55:06 -0400 Content-Disposition: inline In-Reply-To: <20151021065704.GM7701@secunet.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On (10/21/15 08:57), Steffen Klassert wrote: > > --- a/net/xfrm/xfrm_user.c > > +++ b/net/xfrm/xfrm_user.c > > @@ -2659,7 +2659,7 @@ static int xfrm_notify_sa(struct xfrm_state *x, const struct km_event *c) > > if (attr == NULL) > > goto out_free_skb; > > > > - p = nla_data(attr); > > + p = PTR_ALIGN(nla_data(attr), __alignof__(*p)); > > Hm, this breaks userspace notifications on 64-bit systems. > Userspace expects this to be aligned to 4, with your patch > it is aligned to 8 on 64-bit. > > Without your patch I get the correct notification when deleting a SA: > But __alignof__(*p) is 8 on sparc, and without the patch I get all types of unaligned access. So what do you suggest as the fix? (and openswan/pluto dont flag any errors with the patch, which is a separate bug). --Sowmini