netfilter: nf_tables: reject destroy command to remove basechain hooks

[ Upstream commit b32ca27fa238ff83427d23bef2a5b741e2a88a1e ]

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>
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 f10419ba6e0bd67808dbb5dd7f5595def65dcee2..0653f1e5e8929c7a7d76f6d3c820f570076f68d0 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2934,7 +2934,8 @@ 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)) {