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: d4bc827 ("netfilter: nf_tables: netlink notifier might race to release objects") Signed-off-by: Pablo Neira Ayuso <[email protected]> Signed-off-by: Florian Westphal <[email protected]>
linux-netdev · Aug 23, 2023 · 2c9f029 · 2c9f029
1 parent 4b80ced
commit 2c9f029
Showing 1 changed file with 1 addition and 1 deletion.
diff --git 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) &&