Chain binding only requires the rule addition/insertion command within
the same transaction. Removal of rules from chain bindings within the
same transaction makes no sense, userspace does not utilize this
feature. Replace nft_chain_is_bound() check to nft_chain_binding() in
rule deletion commands. Replace command implies a rule deletion, reject
this command too.
Rule flush command can also safely rely on this nft_chain_binding()
check because unbound chains are not allowed since 62e1e94b246e
("netfilter: nf_tables: reject unbound chain set before commit phase").
Fixes: d0e2c7de92c7 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e429ebba74b3..895c6e4fba97 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1432,7 +1432,7 @@ static int nft_flush_table(struct nft_ctx *ctx)
if (!nft_is_active_next(ctx->net, chain))
continue;
- if (nft_chain_is_bound(chain))
+ if (nft_chain_binding(chain))
continue;
ctx->chain = chain;
@@ -1477,7 +1477,7 @@ static int nft_flush_table(struct nft_ctx *ctx)
if (!nft_is_active_next(ctx->net, chain))
continue;
- if (nft_chain_is_bound(chain))
+ if (nft_chain_binding(chain))
continue;
ctx->chain = chain;
@@ -2910,6 +2910,9 @@ static int nf_tables_delchain(struct sk_buff *skb, const struct nfnl_info *info,
return PTR_ERR(chain);
}
+ if (nft_chain_binding(chain))
+ return -EOPNOTSUPP;
+
nft_ctx_init(&ctx, net, skb, info->nlh, family, table, chain, nla);
if (nla[NFTA_CHAIN_HOOK]) {
@@ -3971,6 +3974,11 @@ static int nf_tables_newrule(struct sk_buff *skb, const struct nfnl_info *info,
}
if (info->nlh->nlmsg_flags & NLM_F_REPLACE) {
+ if (nft_chain_binding(chain)) {
+ err = -EOPNOTSUPP;
+ goto err_destroy_flow_rule;
+ }
+
err = nft_delrule(&ctx, old_rule);
if (err < 0)
goto err_destroy_flow_rule;
@@ -4078,7 +4086,7 @@ static int nf_tables_delrule(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))
+ if (nft_chain_binding(chain))
return -EOPNOTSUPP;
}
@@ -4112,7 +4120,7 @@ static int nf_tables_delrule(struct sk_buff *skb, const struct nfnl_info *info,
list_for_each_entry(chain, &table->chains, list) {
if (!nft_is_active_next(net, chain))
continue;
- if (nft_chain_is_bound(chain))
+ if (nft_chain_binding(chain))
continue;
ctx.chain = chain;
@@ -11054,7 +11062,7 @@ static void __nft_release_table(struct net *net, struct nft_table *table)
ctx.family = table->family;
ctx.table = table;
list_for_each_entry(chain, &table->chains, list) {
- if (nft_chain_is_bound(chain))
+ if (nft_chain_binding(chain))
continue;
ctx.chain = chain;
--
2.30.2
