netfilter: nf_tables: reject unbound chain set before commit phase

[ Upstream commit 62e1e94b246e685d89c3163aaef4b160e42ceb02 ]

Use binding list to track set transaction and to check for unbound
chains before entering the commit phase.

Bail out if chain binding remain unused before entering the commit
step.

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 2e3a374db1b9f96a2ccbcb4f4b2d262a9f9d9fcd..f0655427503760301c7841ca3b4269055a4beffe 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -372,6 +372,11 @@ static void nft_trans_commit_list_add_tail(struct net *net, struct nft_trans *tr
                    nft_set_is_anonymous(nft_trans_set(trans)))
                        list_add_tail(&trans->binding_list, &nft_net->binding_list);
                break;
+       case NFT_MSG_NEWCHAIN:
+               if (!nft_trans_chain_update(trans) &&
+                   nft_chain_binding(nft_trans_chain(trans)))
+                       list_add_tail(&trans->binding_list, &nft_net->binding_list);
+               break;
        }
 
        list_add_tail(&trans->list, &nft_net->commit_list);
@@ -9419,6 +9424,14 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
                                return -EINVAL;
                        }
                        break;
+               case NFT_MSG_NEWCHAIN:
+                       if (!nft_trans_chain_update(trans) &&
+                           nft_chain_binding(nft_trans_chain(trans)) &&
+                           !nft_trans_chain_bound(trans)) {
+                               pr_warn_once("nftables ruleset with unbound chain\n");
+                               return -EINVAL;
+                       }
+                       break;
                }
        }