From 2c9f0293280e258606e54ed2b96fa71498432eae Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 18 Aug 2023 01:13:31 +0200 Subject: [PATCH] netfilter: nf_tables: flush pending destroy work before netlink notifier Destroy work waits for the RCU grace period then it releases the objects with no mutex held. All releases objects follow this path for transactions, therefore, order is guaranteed and references to top-level objects in the hierarchy remain valid. However, netlink notifier might interfer with pending destroy work. rcu_barrier() is not correct because objects are not release via RCU callback. Flush destroy work before releasing objects from netlink notifier path. Fixes: d4bc8271db21 ("netfilter: nf_tables: netlink notifier might race to release objects") Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal --- net/netfilter/nf_tables_api.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index a76a62ebe9c936..d299e7aa1b9658 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -11073,7 +11073,7 @@ static int nft_rcv_nl_event(struct notifier_block *this, unsigned long event, gc_seq = nft_gc_seq_begin(nft_net); if (!list_empty(&nf_tables_destroy_list)) - rcu_barrier(); + nf_tables_trans_destroy_flush_work(); again: list_for_each_entry(table, &nft_net->tables, list) { if (nft_table_has_owner(table) &&