From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: [PATCH net-next] ixgbe: Avoid unaligned access in ixgbe_atr() for LLC packets Date: Mon, 14 Mar 2016 11:32:16 -0400 Message-ID: <20160314153216.GF5084@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: sowmini.varadhan@oracle.com, 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 To: intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:19921 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933015AbcCNPcX (ORCPT ); Mon, 14 Mar 2016 11:32:23 -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. Signed-off-by: Sowmini Varadhan --- 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..c3885a8 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c @@ -7602,6 +7602,11 @@ static void ixgbe_atr(struct ixgbe_ring *ring, #endif /* CONFIG_IXGBE_VXLAN */ } + if (skb->protocol != htons(ETH_P_IP) && + skb->protocol != htons(ETH_P_IPV6) && + skb->protocol != htons(ETH_P_ARP)) + return; + /* Currently only IPv4/IPv6 with TCP is supported */ switch (hdr.ipv4->version) { case IPVERSION: -- 1.7.1