From: Jozsef Kadlecsik <kadlec@netfilter.org>
Date: Thu, 2 Jul 2026 13:46:57 +0000 (+0200)
Subject: netfilter: ipset: mark the rcu locked areas properly
X-Git-Tag: v7.2-rc3~29^2~3^2~11
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=5d0c22e73656d050daffad10a2ba8765ce8441c8;p=thirdparty%2Fkernel%2Fstable.git

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 <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---

diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index dedf59b661ddf..c9a0717662438 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));