[PATCH 5.19 059/158] netfilter: nf_tables: do not leave chain stats enabled on error

From: Greg Kroah-Hartman
Date: Mon Aug 29 2022 - 07:24:56 EST


From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>

[ Upstream commit 43eb8949cfdffa764b92bc6c54b87cbe5b0003fe ]

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@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index e171257739c2f..b2c89e8c2a655 100644
--- 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;
--
2.35.1