Re: [Intel-wired-lan] [PATCH net-next] ixgbe: Avoid unaligned access in ixgbe_atr() for LLC packets
From: Alexander Duyck <hidden>
Date: 2016-03-14 17:12:50
Also in:
intel-wired-lan
On Mon, Mar 14, 2016 at 8:32 AM, Sowmini Varadhan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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; +
This is disabling too much as it snags VLAN along with everything else. Replace skb->protocol with first->protocol and this should work correctly. You may also want to move it up by several lines so that you don't count it as a valid ATR frame via atr_count. Thanks. - Alex