[PATCH net 3/3] netfilter: nf_tables: disallow rule addition to bound chain via NFTA_RULE_CHAIN_ID

From: Pablo Neira Ayuso <pablo@netfilter.org>

Bail out with EOPNOTSUPP when adding rule to bound chain via
NFTA_RULE_CHAIN_ID. The following warning splat is shown when
adding a rule to a deleted bound chain:

 WARNING: CPU: 2 PID: 13692 at net/netfilter/nf_tables_api.c:2013 nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
 CPU: 2 PID: 13692 Comm: chain-bound-rul Not tainted 6.1.39 #1
 RIP: 0010:nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <redacted>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 net/netfilter/nf_tables_api.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index b9a4d3fd1d34..d3c6ecd1f5a6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c

@@ -3811,8 +3811,6 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 			NL_SET_BAD_ATTR(extack, nla[NFTA_RULE_CHAIN]);
 			return PTR_ERR(chain);
 		}
-		if (nft_chain_is_bound(chain))
-			return -EOPNOTSUPP;
 
 	} else if (nla[NFTA_RULE_CHAIN_ID]) {
 		chain = nft_chain_lookup_byid(net, table, nla[NFTA_RULE_CHAIN_ID],

@@ -3825,6 +3823,9 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
 		return -EINVAL;
 	}
 
+	if (nft_chain_is_bound(chain))
+		return -EOPNOTSUPP;
+
 	if (nla[NFTA_RULE_HANDLE]) {
 		handle = be64_to_cpu(nla_get_be64(nla[NFTA_RULE_HANDLE]));
 		rule = __nft_rule_lookup(chain, handle);

-- 
2.41.0