--- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1234,7 +1234,7 @@ static inline int ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); - const struct iphdr *iph = ip_hdr(skb); + const struct iphdr *iph; int encap_limit = -1; struct flowi6 fl6; __u8 dsfield; @@ -1242,6 +1242,11 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) u8 tproto; int err; + /* ensure we can access the full inner ip header */ + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return -1; + + iph = ip_hdr(skb); memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); tproto = READ_ONCE(t->parms.proto); @@ -1306,7 +1311,7 @@ static inline int ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) { struct ip6_tnl *t = netdev_priv(dev); - struct ipv6hdr *ipv6h = ipv6_hdr(skb); + struct ipv6hdr *ipv6h; int encap_limit = -1; __u16 offset; struct flowi6 fl6; @@ -1315,6 +1320,10 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) u8 tproto; int err; + if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h)))) + return -1; + + ipv6h = ipv6_hdr(skb); tproto = READ_ONCE(t->parms.proto); if ((tproto != IPPROTO_IPV6 && tproto != 0) || ip6_tnl_addr_conflict(t, ipv6h))