From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: [PATCH V3 net-next] ixgbe: Avoid unaligned access in ixgbe_atr() for LLC packets Date: Mon, 14 Mar 2016 15:47:16 -0400 Message-ID: <20160314194716.GM5084@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jeffrey.t.kirsher@intel.com, jesse.brandeburg@intel.com, shannon.nelson@intel.com, carolyn.wyborny@intel.com, donald.c.skidmore@intel.com, bruce.w.allan@intel.com, john.ronciak@intel.com, mitch.a.williams@intel.com, sowmini.varadhan@oracle.com To: intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org, alexander.duyck@gmail.com Return-path: Received: from aserp1040.oracle.com ([141.146.126.69]:35652 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755505AbcCNTr3 (ORCPT ); Mon, 14 Mar 2016 15:47:29 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: For LLC based protocols like lldp, stp etc., the ethernet header is an 802.3 header with a h_proto that is not 0x800, 0x86dd, or even 0x806. In this world, the skb_network_header() points at the DSAP/SSAP/.. and is not likely to be NET_IP_ALIGNed in ixgbe_atr(). With LLC, drivers are not likely to correctly find IPVERSION, or "6", at hdr.ipv4->version, but will instead just needlessly trigger an unaligned access. (IPv4/IPv6 over LLC is almost never implemented). The unaligned access is thus avoidable: bail out quickly after examining skb->protocol. The only Ethernet II protocols handled are IPv4 and IPv6 Signed-off-by: Sowmini Varadhan --- v2: Alexander Duyck comments v3: filter out all ethertypes except for Ethernet II and (IPv4 or IPv6) drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c index 4d6223d..aeab2fe 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -7574,6 +7574,11 @@ static void ixgbe_atr(struct ixgbe_ring *ring, if (!ring->atr_sample_rate) return; + /* this function only handles IPv4 or IPv6 */ + if (first->protocol != htons(ETH_P_IP) && + first->protocol != htons(ETH_P_IPV6)) + return; + ring->atr_count++; /* snag network header to get L4 type and address */ -- 1.7.1