ip6_tunnel: fix possible use-after-free on xmit

ip4ip6/ip6ip6 tunnels run iptunnel_handle_offloads on xmit which
can cause a possible use-after-free accessing iph/ipv6h pointer
since the packet will be 'uncloned' running pskb_expand_head if
it is a cloned gso skb.

Fixes: 0e9a709560 ("ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Haishuang Yan 2019-07-26 00:40:17 +08:00 коммит произвёл David S. Miller
Родитель c5d139697d
Коммит 01f5bffad5
1 изменённых файлов: 2 добавлений и 4 удалений

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@ -1278,12 +1278,11 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
}
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
return -1;
dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
skb_set_inner_ipproto(skb, IPPROTO_IPIP);
err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
@ -1367,12 +1366,11 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
}
fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
return -1;
dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
skb_set_inner_ipproto(skb, IPPROTO_IPV6);
err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,