From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: [PATCH net-next] net/vxlan: Avoid unaligned access in vxlan_build_skb() Date: Tue, 20 Sep 2016 10:27:00 -0400 Message-ID: <20160920142700.GJ8920@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, jbenc@redhat.com, hannes@stressinduktion.org, aduyck@mirantis.com, daniel@iogearbox.net, pabeni@redhat.com, sowmini.varadhan@oracle.com To: netdev@vger.kernel.org Return-path: Received: from userp1040.oracle.com ([156.151.31.81]:25113 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754714AbcITO1f (ORCPT ); Tue, 20 Sep 2016 10:27:35 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: The vxlan header is at offset (14 + 20 + 8) into the packet, so the vxh is not aligned in vxlan_build_skb. Use [get/put]_unaligned functions to modify flags and vni field in the vxh. Signed-off-by: Sowmini Varadhan --- drivers/net/vxlan.c | 10 ++++++---- 1 files changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c index e7d1668..f903fa4 100644 --- a/drivers/net/vxlan.c +++ b/drivers/net/vxlan.c @@ -1751,15 +1751,17 @@ static int vxlan_build_skb(struct sk_buff *skb, struct dst_entry *dst, goto out_free; vxh = (struct vxlanhdr *) __skb_push(skb, sizeof(*vxh)); - vxh->vx_flags = VXLAN_HF_VNI; - vxh->vx_vni = vxlan_vni_field(vni); + put_unaligned(VXLAN_HF_VNI, &vxh->vx_flags); + put_unaligned(vxlan_vni_field(vni), &vxh->vx_vni); if (type & SKB_GSO_TUNNEL_REMCSUM) { unsigned int start; + __be32 tmpvni = get_unaligned(&vxh->vx_vni); start = skb_checksum_start_offset(skb) - sizeof(struct vxlanhdr); - vxh->vx_vni |= vxlan_compute_rco(start, skb->csum_offset); - vxh->vx_flags |= VXLAN_HF_RCO; + tmpvni |= vxlan_compute_rco(start, skb->csum_offset); + put_unaligned(tmpvni, &vxh->vx_vni); + put_unaligned(VXLAN_HF_VNI | VXLAN_HF_RCO, &vxh->vx_flags); if (!skb_is_gso(skb)) { skb->ip_summed = CHECKSUM_NONE; -- 1.7.1