[PATCH 5.19 055/158] netfilter: nf_tables: disallow updates of implicit chain

From: Greg Kroah-Hartman
Date: Mon Aug 29 2022 - 07:26:12 EST


From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

[ Upstream commit 5dc52d83baac30decf5f3b371d5eb41dfa1d1412 ]

Updates on existing implicit chain make no sense, disallow this.

Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4bd6e9427c918..8b6ee9df817fb 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2574,6 +2574,9 @@ static int nf_tables_newchain(struct sk_buff *skb, const struct nfnl_info *info,
nft_ctx_init(&ctx, net, skb, info->nlh, family, table, chain, nla);

if (chain != NULL) {
+ if (chain->flags & NFT_CHAIN_BINDING)
+ return -EINVAL;
+
if (info->nlh->nlmsg_flags & NLM_F_EXCL) {
NL_SET_BAD_ATTR(extack, attr);
return -EEXIST;
--
2.35.1