diff options
Diffstat (limited to 'net/ipv4/ip_gre.c')
| -rw-r--r-- | net/ipv4/ip_gre.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index a85ae2f7a21c..303012adf9e6 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -750,6 +750,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev int gre_hlen; __be32 dst; int mtu; + u8 ttl; if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb)) @@ -760,7 +761,10 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev if (dev->header_ops && dev->type == ARPHRD_IPGRE) { gre_hlen = 0; - tiph = (const struct iphdr *)skb->data; + if (skb->protocol == htons(ETH_P_IP)) + tiph = (const struct iphdr *)skb->data; + else + tiph = &tunnel->parms.iph; } else { gre_hlen = tunnel->hlen; tiph = &tunnel->parms.iph; @@ -812,6 +816,7 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev goto tx_error; } + ttl = tiph->ttl; tos = tiph->tos; if (tos == 1) { tos = 0; @@ -904,11 +909,12 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev dev_kfree_skb(skb); skb = new_skb; old_iph = ip_hdr(skb); + /* Warning : tiph value might point to freed memory */ } - skb_reset_transport_header(skb); skb_push(skb, gre_hlen); skb_reset_network_header(skb); + skb_set_transport_header(skb, sizeof(*iph)); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); @@ -927,8 +933,9 @@ static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb); iph->daddr = fl4.daddr; iph->saddr = fl4.saddr; + iph->ttl = ttl; - if ((iph->ttl = tiph->ttl) == 0) { + if (ttl == 0) { if (skb->protocol == htons(ETH_P_IP)) iph->ttl = old_iph->ttl; #if IS_ENABLED(CONFIG_IPV6) |