netfilter: nf_tables: do not leave chain stats enabled on error

Error might occur later in the nf_tables_addchain() codepath, enable
static key only after transaction has been created.

Fixes: 9f08ea848117 ("netfilter: nf_tables: keep chain counters away from hot path")
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 0951f31..72c066a 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2195,9 +2195,9 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
                              struct netlink_ext_ack *extack)
 {
        const struct nlattr * const *nla = ctx->nla;
+       struct nft_stats __percpu *stats = NULL;
        struct nft_table *table = ctx->table;
        struct nft_base_chain *basechain;
-       struct nft_stats __percpu *stats;
        struct net *net = ctx->net;
        char name[NFT_NAME_MAXLEN];
        struct nft_rule_blob *blob;
@@ -2235,7 +2235,6 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
                                return PTR_ERR(stats);
                        }
                        rcu_assign_pointer(basechain->stats, stats);
-                       static_branch_inc(&nft_counters_enabled);
                }
 
                err = nft_basechain_init(basechain, family, &hook, flags);
@@ -2318,6 +2317,9 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
                goto err_unregister_hook;
        }
 
+       if (stats)
+               static_branch_inc(&nft_counters_enabled);
+
        table->use++;
 
        return 0;