From 7f4f7dd4417d9efd038b14d39c70170db2e0baa0 Mon Sep 17 00:00:00 2001 From: Vishwanath Pai Date: Mon, 11 Sep 2017 21:52:40 +0200 Subject: [PATCH] netfilter: ipset: ipset list may return wrong member count for set with timeout Simple testcase: $ ipset create test hash:ip timeout 5 $ ipset add test 1.2.3.4 $ ipset add test 1.2.2.2 $ sleep 5 $ ipset l Name: test Type: hash:ip Revision: 5 Header: family inet hashsize 1024 maxelem 65536 timeout 5 Size in memory: 296 References: 0 Number of entries: 2 Members: We return "Number of entries: 2" but no members are listed. That is because mtype_list runs "ip_set_timeout_expired" and does not list the expired entries, but set->elements is never upated (until mtype_gc cleans it up later). Reviewed-by: Joshua Hunt Signed-off-by: Vishwanath Pai Signed-off-by: Jozsef Kadlecsik Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_hash_gen.h | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h index f236c0bc7b3f..51063d9ed0f7 100644 --- a/net/netfilter/ipset/ip_set_hash_gen.h +++ b/net/netfilter/ipset/ip_set_hash_gen.h @@ -1041,12 +1041,24 @@ out: static int mtype_head(struct ip_set *set, struct sk_buff *skb) { - const struct htype *h = set->data; + struct htype *h = set->data; const struct htable *t; struct nlattr *nested; size_t memsize; u8 htable_bits; + /* If any members have expired, set->elements will be wrong + * mytype_expire function will update it with the right count. + * we do not hold set->lock here, so grab it first. + * set->elements can still be incorrect in the case of a huge set, + * because elements might time out during the listing. + */ + if (SET_WITH_TIMEOUT(set)) { + spin_lock_bh(&set->lock); + mtype_expire(set, h); + spin_unlock_bh(&set->lock); + } + rcu_read_lock_bh(); t = rcu_dereference_bh_nfnl(h->table); memsize = mtype_ahash_memsize(h, t) + set->ext_size; -- 2.20.1