[PATCH 6.8 708/715] netfilter: nf_tables: Fix a memory leak in nf_tables_updchain

Sasha Levin
2024-03-24T22:46:42Z

From: Quan Tian <tianquan23@gmail.com>

[ Upstream commit 7eaf837a4eb5f74561e2486972e7f5184b613f6e ]

If nft_netdev_register_hooks() fails, the memory associated with
nft_stats is not freed, causing a memory leak.

This patch fixes it by moving nft_stats_alloc() down after
nft_netdev_register_hooks() succeeds.

Fixes: b9703ed44ffb ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Quan Tian <tianquan23@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/netfilter/nf_tables_api.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 0fe2abf27d12f..6873c9815cd31 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2619,19 +2619,6 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
}
}

- if (nla[NFTA_CHAIN_COUNTERS]) {
- if (!nft_is_base_chain(chain)) {
- err = -EOPNOTSUPP;
- goto err_hooks;
- }
-
- stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
- if (IS_ERR(stats)) {
- err = PTR_ERR(stats);
- goto err_hooks;
- }
- }
-
if (!(table->flags & NFT_TABLE_F_DORMANT) &&
nft_is_base_chain(chain) &&
!list_empty(&hook.list)) {
@@ -2646,6 +2633,20 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy,
}

unregister = true;
+
+ if (nla[NFTA_CHAIN_COUNTERS]) {
+ if (!nft_is_base_chain(chain)) {
+ err = -EOPNOTSUPP;
+ goto err_hooks;
+ }
+
+ stats = nft_stats_alloc(nla[NFTA_CHAIN_COUNTERS]);
+ if (IS_ERR(stats)) {
+ err = PTR_ERR(stats);
+ goto err_hooks;
+ }
+ }
+
err = -ENOMEM;
trans = nft_trans_alloc(ctx, NFT_MSG_NEWCHAIN,
sizeof(struct nft_trans_chain));
--
2.43.0