From: William Tu Date: Wed, 7 Mar 2018 23:38:48 +0000 (-0800) Subject: openvswitch: fix vport packet length check. X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=46e371f0e78a82186a83cbcb4f4b8850417c7dd5;p=linux.git openvswitch: fix vport packet length check. When sending a packet to a tunnel device, the dev's hard_header_len could be larger than the skb->len in function packet_length(). In the case of ip6gretap/erspan, hard_header_len = LL_MAX_HEADER + t_hlen, which is around 180, and an ARP packet sent to this tunnel has skb->len = 42. This causes the 'unsign int length' to become super large because it is negative value, causing the later ovs_vport_send to drop it due to over-mtu size. The patch fixes it by setting it to 0. Signed-off-by: William Tu Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c index b6c8524032a06..f81c1d0ddff4d 100644 --- a/net/openvswitch/vport.c +++ b/net/openvswitch/vport.c @@ -464,10 +464,10 @@ int ovs_vport_receive(struct vport *vport, struct sk_buff *skb, return 0; } -static unsigned int packet_length(const struct sk_buff *skb, - struct net_device *dev) +static int packet_length(const struct sk_buff *skb, + struct net_device *dev) { - unsigned int length = skb->len - dev->hard_header_len; + int length = skb->len - dev->hard_header_len; if (!skb_vlan_tag_present(skb) && eth_type_vlan(skb->protocol)) @@ -478,7 +478,7 @@ static unsigned int packet_length(const struct sk_buff *skb, * account for 802.1ad. e.g. is_skb_forwardable(). */ - return length; + return length > 0 ? length : 0; } void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)