3.16.40-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eli Cooper <elicooper@xxxxxxx> commit 23f4ffedb7d751c7e298732ba91ca75d224bc1a6 upstream. skb->cb may contain data from previous layers. In the observed scenario, the garbage data were misinterpreted as IP6CB(skb)->frag_max_size, so that small packets sent through the tunnel are mistakenly fragmented. This patch unconditionally clears the control buffer in ip6tunnel_xmit(), which affects ip6_tunnel, ip6_udp_tunnel and ip6_gre. Currently none of these tunnels set IP6CB(skb)->flags, otherwise it needs to be done earlier. Signed-off-by: Eli Cooper <elicooper@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- include/net/ip6_tunnel.h | 1 + 1 file changed, 1 insertion(+) --- a/include/net/ip6_tunnel.h +++ b/include/net/ip6_tunnel.h @@ -75,6 +75,7 @@ static inline void ip6tunnel_xmit(struct struct net_device_stats *stats = &dev->stats; int pkt_len, err; + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); pkt_len = skb->len; err = ip6_local_out(skb);