diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index c445d57e3a5b..b149a7219084 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -220,6 +220,18 @@ static int nft_delchain(struct nft_ctx *ctx) return err; } +/* either expr ops provide both activate/deactivate, or neither */ +static bool nft_expr_check_ops(const struct nft_expr_ops *ops) +{ + if (!ops) + return true; + + if (WARN_ON_ONCE((!ops->activate ^ !ops->deactivate))) + return false; + + return true; +} + static void nft_rule_expr_activate(const struct nft_ctx *ctx, struct nft_rule *rule) { @@ -1724,6 +1736,9 @@ static int nf_tables_delchain(struct net *net, struct sock *nlsk, */ int nft_register_expr(struct nft_expr_type *type) { + if (!nft_expr_check_ops(type->ops)) + return -EINVAL; + nfnl_lock(NFNL_SUBSYS_NFTABLES); if (type->family == NFPROTO_UNSPEC) list_add_tail_rcu(&type->list, &nf_tables_expressions); @@ -1873,6 +1888,10 @@ static int nf_tables_expr_parse(const struct nft_ctx *ctx, err = PTR_ERR(ops); goto err1; } + if (!nft_expr_check_ops(ops)) { + err = -EINVAL; + goto err1; + } } else ops = type->ops;