From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Steffen Subject: Re: static inline int xfrm_mark_get() broken Date: Wed, 30 Jun 2010 07:03:05 +0200 Message-ID: <4C2AD009.40306@hsr.ch> References: <4C28EE19.2090502@hsr.ch> <20100630044637.GV2138@verge.net.au> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: "Steffen Andreas (asteffen@hsr.ch)" , "netdev@vger.kernel.org" , jamal To: Simon Horman Return-path: Received: from sitav-80024.hsr.ch ([152.96.80.24]:56128 "EHLO strongswan.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750897Ab0F3GCl (ORCPT ); Wed, 30 Jun 2010 02:02:41 -0400 In-Reply-To: <20100630044637.GV2138@verge.net.au> Sender: netdev-owner@vger.kernel.org List-ID: Hello Simon, actually I don't care how this bug is going to be fixed, but with sizeof(struct xfrm_mark) I'm dead certain that both the mark value and mask are being copied. Actually in the next inline function right below sizeof(struct xfrm_mark) is used, too: static inline int xfrm_mark_put(struct sk_buff *skb, struct xfrm_mark *m) { if (m->m | m->v) NLA_PUT(skb, XFRMA_MARK, sizeof(struct xfrm_mark), m); return 0; Regards Andreas On 06/30/2010 06:46 AM, Simon Horman wrote: > On Mon, Jun 28, 2010 at 08:46:49PM +0200, Andreas Steffen wrote: >> Hi, >> >> experimenting with the new XFRM_MARK feature of the 2.6.34 kernel >> I found out that the extraction of the mark mask might accidentally >> work on 64 bit platforms but on 32 bit platforms the function is >> awfully broken. The rather trivial patch attached to this mail fixes >> the problem. Otherwise the XFRM_MARK feature seems quite promising! >> >> Best regards >> >> Andreas >> >> ====================================================================== >> Andreas Steffen e-mail: andreas.steffen@hsr.ch >> Institute for Internet Technologies and Applications >> Hochschule fuer Technik Rapperswil phone: +41 55 222 42 68 >> CH-8640 Rapperswil (Switzerland) mobile: +41 76 340 25 56 >> ===========================================================[ITA-HSR]== > >> --- linux/include/net/xfrm.h.ori 2010-06-28 18:53:28.229489876 +0200 >> +++ linux/include/net/xfrm.h 2010-06-28 18:53:50.745487383 +0200 >> @@ -1587,7 +1587,7 @@ >> static inline int xfrm_mark_get(struct nlattr **attrs, struct xfrm_mark *m) >> { >> if (attrs[XFRMA_MARK]) >> - memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(m)); >> + memcpy(m, nla_data(attrs[XFRMA_MARK]), sizeof(struct xfrm_mark)); > > This fix looks correct to me, but > I believe that sizeof(*m) is the preferred style. > >> else >> m->v = m->m = 0; ====================================================================== Andreas Steffen e-mail: andreas.steffen@hsr.ch Institute for Internet Technologies and Applications Hochschule fuer Technik Rapperswil phone: +41 55 222 42 68 CH-8640 Rapperswil (Switzerland) mobile: +41 76 340 25 56 ===========================================================[ITA-HSR]==