From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 2/2] netfilter: ipset: ipset list may return wrong member count for set with timeout
Date: Wed, 20 Sep 2017 12:49:03 +0200 [thread overview]
Message-ID: <1505904543-10004-3-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1505904543-10004-1-git-send-email-pablo@netfilter.org>
From: Vishwanath Pai <vpai@akamai.com>
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 <johunt@akamai.com>
Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
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 @@ mtype_test(struct ip_set *set, void *value, const struct ip_set_ext *ext,
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;
--
2.1.4
next prev parent reply other threads:[~2017-09-20 10:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-20 10:49 [PATCH 0/2] Netfilter fixes for net Pablo Neira Ayuso
2017-09-20 10:49 ` [PATCH 1/2] netfilter: nat: Do not use ARRAY_SIZE() on spinlocks to fix zero div Pablo Neira Ayuso
2017-09-20 10:49 ` Pablo Neira Ayuso [this message]
2017-09-20 23:08 ` [PATCH 0/2] Netfilter fixes for net David Miller
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