From d91e8db5b629a3c8c81db4dc317a66c7b5591821 Mon Sep 17 00:00:00 2001 From: William Tu Date: Fri, 15 Dec 2017 14:27:44 -0800 Subject: [PATCH] net: erspan: reload pointer after pskb_may_pull pskb_may_pull() can change skb->data, so we need to re-load pkt_md and ershdr at the right place. Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support") Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre") Signed-off-by: William Tu Cc: Haishuang Yan Signed-off-by: David S. Miller --- net/ipv4/ip_gre.c | 4 +++- net/ipv6/ip6_gre.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index b3a32a980240..fd4d6e96da7e 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -279,7 +279,6 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, * Use ERSPAN 10-bit session ID as key. */ tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK); - pkt_md = (struct erspan_metadata *)(ershdr + 1); tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags | TUNNEL_KEY, iph->saddr, iph->daddr, tpi->key); @@ -289,6 +288,9 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi, if (unlikely(!pskb_may_pull(skb, len))) return PACKET_REJECT; + ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len); + pkt_md = (struct erspan_metadata *)(ershdr + 1); + if (__iptunnel_pull_header(skb, len, htons(ETH_P_TEB), diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index b3e4e0384f36..87b9892dfa23 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -515,7 +515,6 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len, ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET; tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK); - pkt_md = (struct erspan_metadata *)(ershdr + 1); tunnel = ip6gre_tunnel_lookup(skb->dev, &ipv6h->saddr, &ipv6h->daddr, tpi->key, @@ -526,6 +525,9 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len, if (unlikely(!pskb_may_pull(skb, len))) return PACKET_REJECT; + ershdr = (struct erspan_base_hdr *)skb->data; + pkt_md = (struct erspan_metadata *)(ershdr + 1); + if (__iptunnel_pull_header(skb, len, htons(ETH_P_TEB), false, false) < 0) -- 2.25.1