netfilter: nf_tables: reject destroy command to remove basechain hooks

Report EOPNOTSUPP if NFT_MSG_DESTROYCHAIN is used to delete hooks in an
existing netdev basechain, thus, only NFT_MSG_DELCHAIN is allowed.

Fixes: 7d937b107108f ("netfilter: nf_tables: support for deleting devices in an existing netdev chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 5fa3d3540c93c003737fb16ef1e6e7514580e97a..a1a8030e16a520efae068860b958189b14ffcbbe 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2944,7 +2944,8 @@ static int nf_tables_delchain(struct sk_buff *skb, const struct nfnl_info *info,
        nft_ctx_init(&ctx, net, skb, info->nlh, family, table, chain, nla);
 
        if (nla[NFTA_CHAIN_HOOK]) {
-               if (chain->flags & NFT_CHAIN_HW_OFFLOAD)
+               if (NFNL_MSG_TYPE(info->nlh->nlmsg_type) == NFT_MSG_DESTROYCHAIN ||
+                   chain->flags & NFT_CHAIN_HW_OFFLOAD)
                        return -EOPNOTSUPP;
 
                if (nft_is_base_chain(chain)) {