netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types

Sashiko pointed out that there are a few lockless RCU readers
using test_bit() which is a relaxed atomic operation and
provides no memory barrier guarantees. Use test_bit_acquire()
instead where the operation may run parallel with add/del/gc,
i.e. is not one from the next cases

- protected by region lock
- in a set destroy phase
- in a new/temporary set creation phase

Fixes: 18f84d41d3 ("netfilter: ipset: Introduce RCU locking in hash:* types")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Jozsef Kadlecsik 2026-06-17 10:41:22 +02:00 committed by Pablo Neira Ayuso
parent f4c2d8668d
commit e4b4984e28

View File

@ -689,7 +689,7 @@ mtype_resize(struct ip_set *set, bool retried)
continue;
pos = smp_load_acquire(&n->pos);
for (j = 0; j < pos; j++) {
if (!test_bit(j, n->used))
if (!test_bit_acquire(j, n->used))
continue;
data = ahash_data(n, j, dsize);
if (SET_ELEM_EXPIRED(set, data))
@ -826,7 +826,7 @@ mtype_ext_size(struct ip_set *set, u32 *elements, size_t *ext_size)
continue;
pos = smp_load_acquire(&n->pos);
for (j = 0; j < pos; j++) {
if (!test_bit(j, n->used))
if (!test_bit_acquire(j, n->used))
continue;
data = ahash_data(n, j, set->dsize);
if (!SET_ELEM_EXPIRED(set, data))
@ -1201,7 +1201,7 @@ mtype_test_cidrs(struct ip_set *set, struct mtype_elem *d,
continue;
pos = smp_load_acquire(&n->pos);
for (i = 0; i < pos; i++) {
if (!test_bit(i, n->used))
if (!test_bit_acquire(i, n->used))
continue;
data = ahash_data(n, i, set->dsize);
if (!mtype_data_equal(data, d, &multi))
@ -1259,7 +1259,7 @@ mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext,
}
pos = smp_load_acquire(&n->pos);
for (i = 0; i < pos; i++) {
if (!test_bit(i, n->used))
if (!test_bit_acquire(i, n->used))
continue;
data = ahash_data(n, i, set->dsize);
if (!mtype_data_equal(data, d, &multi))
@ -1396,7 +1396,7 @@ mtype_list(const struct ip_set *set,
continue;
pos = smp_load_acquire(&n->pos);
for (i = 0; i < pos; i++) {
if (!test_bit(i, n->used))
if (!test_bit_acquire(i, n->used))
continue;
e = ahash_data(n, i, set->dsize);
if (SET_ELEM_EXPIRED(set, e))