From 5d0c22e73656d050daffad10a2ba8765ce8441c8 Mon Sep 17 00:00:00 2001 From: Jozsef Kadlecsik Date: Thu, 2 Jul 2026 15:46:57 +0200 Subject: [PATCH] netfilter: ipset: mark the rcu locked areas properly When we bump the uref counter, there's no need to keep the rcu lock because the referred hash table can't disappear. Also, from the same reason in mtype_gc we need the rcu lock and not a spinlock. Signed-off-by: Jozsef Kadlecsik Signed-off-by: Florian Westphal --- net/netfilter/ipset/ip_set_hash_gen.h | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index dedf59b661dd..c9a071766243 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -569,9 +569,10 @@ mtype_gc(struct work_struct *work) set = gc->set; h = set->data; - spin_lock_bh(&set->lock); - t = ipset_dereference_set(h->table, set); + rcu_read_lock_bh(); + t = rcu_dereference_bh(h->table); atomic_inc(&t->uref); + rcu_read_unlock_bh(); numof_locks = ahash_numof_locks(t->htable_bits); r = gc->region++; if (r >= numof_locks) { @@ -580,7 +581,6 @@ mtype_gc(struct work_struct *work) next_run = (IPSET_GC_PERIOD(set->timeout) * HZ) / numof_locks; if (next_run < HZ/10) next_run = HZ/10; - spin_unlock_bh(&set->lock); mtype_gc_do(set, h, t, r); @@ -860,15 +860,13 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, key = HKEY(value, h->initval, t->htable_bits); r = ahash_region(key); atomic_inc(&t->uref); + rcu_read_unlock_bh(); elements = t->hregion[r].elements; maxelem = t->maxelem; if (elements >= maxelem) { u32 e; - if (SET_WITH_TIMEOUT(set)) { - rcu_read_unlock_bh(); + if (SET_WITH_TIMEOUT(set)) mtype_gc_do(set, h, t, r); - rcu_read_lock_bh(); - } maxelem = h->maxelem; elements = 0; for (e = 0; e < ahash_numof_locks(t->htable_bits); e++) @@ -876,7 +874,6 @@ mtype_add(struct ip_set *set, void *value, const struct ip_set_ext *ext, if (elements >= maxelem && SET_WITH_FORCEADD(set)) forceadd = true; } - rcu_read_unlock_bh(); spin_lock_bh(&t->hregion[r].lock); n = rcu_dereference_bh(hbucket(t, key)); -- 2.47.3