From: Xin Long lucien.xin@gmail.com
commit 976eba8ab596bab94b9714cd46d38d5c6a2c660d upstream.
In Commit dd9ee3444014 ("vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel"), it tries to receive IPIP packets in vti by calling xfrm_input(). This case happens when a small packet or frag sent by peer is too small to get compressed.
However, xfrm_input() will still get to the IPCOMP path where skb sec_path is set, but never dropped while it should have been done in vti_ipcomp4_protocol.cb_handler(vti_rcv_cb), as it's not an ipcomp4 packet. This will cause that the packet can never pass xfrm4_policy_check() in the upper protocol rcv functions.
So this patch is to call ip_tunnel_rcv() to process IPIP packets instead.
Fixes: dd9ee3444014 ("vti4: Fix a ipip packet processing bug in 'IPCOMP' virtual tunnel") Reported-by: Xiumei Mu xmu@redhat.com Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/ipv4/ip_vti.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-)
--- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -99,7 +99,28 @@ static int vti_rcv_proto(struct sk_buff
static int vti_rcv_tunnel(struct sk_buff *skb) { - return vti_rcv(skb, ip_hdr(skb)->saddr, true); + struct ip_tunnel_net *itn = net_generic(dev_net(skb->dev), vti_net_id); + const struct iphdr *iph = ip_hdr(skb); + struct ip_tunnel *tunnel; + + tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY, + iph->saddr, iph->daddr, 0); + if (tunnel) { + struct tnl_ptk_info tpi = { + .proto = htons(ETH_P_IP), + }; + + if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) + goto drop; + if (iptunnel_pull_header(skb, 0, tpi.proto)) + goto drop; + return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, false); + } + + return -EINVAL; +drop: + kfree_skb(skb); + return 0; }
static int vti_rcv_cb(struct sk_buff *skb, int err)