[PATCH nf 2/4] netfilter: nft_flow_offload: do not make un-established tcp flow_offload session.

[Taehee Yoo]

nft_flow_offload_eval() makes flow_offload session but it doesn't check
tcp state.
So, it can make un-ESTABLISHED tcp flow offload session such as SYN-RECV.
But, this is not a normal case.

Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Signed-off-by: Taehee Yoo <ap420...@gmail.com>
---
 net/netfilter/nft_flow_offload.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index ff50bc1b144f..8538ddf9c6bf 100644
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -84,6 +84,9 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
 
        switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
        case IPPROTO_TCP:
+               if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
+                       goto out;
+               break;
        case IPPROTO_UDP:
                break;
        default:
-- 
2.17.1