From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 13/25] netfilter: conntrack: protect early_drop by rcu read lock
Date: Sat, 23 Jul 2016 13:08:27 +0200 [thread overview]
Message-ID: <1469272119-29942-14-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1469272119-29942-1-git-send-email-pablo@netfilter.org>
From: Liping Zhang <liping.zhang@spreadtrum.com>
User can add ct entry via nfnetlink(IPCTNL_MSG_CT_NEW), and if the total
number reach the nf_conntrack_max, we will try to drop some ct entries.
But in this case(the main function call path is ctnetlink_create_conntrack
-> nf_conntrack_alloc -> early_drop), rcu_read_lock is not held, so race
with hash resize will happen.
Fixes: 242922a02717 ("netfilter: conntrack: simplify early_drop")
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_conntrack_core.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index e0e9c9a..2d46225 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -880,6 +880,7 @@ static noinline int early_drop(struct net *net, unsigned int _hash)
struct hlist_nulls_head *ct_hash;
unsigned hash, sequence, drops;
+ rcu_read_lock();
do {
sequence = read_seqcount_begin(&nf_conntrack_generation);
hash = scale_hash(_hash++);
@@ -887,6 +888,8 @@ static noinline int early_drop(struct net *net, unsigned int _hash)
} while (read_seqcount_retry(&nf_conntrack_generation, sequence));
drops = early_drop_list(net, &ct_hash[hash]);
+ rcu_read_unlock();
+
if (drops) {
NF_CT_STAT_ADD_ATOMIC(net, early_drop, drops);
return true;
--
2.1.4
next prev parent reply other threads:[~2016-07-23 11:08 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-23 11:08 [PATCH 00/25] Netfilter/IPVS updates for net-next Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 01/25] ipvs: count pre-established TCP states as active Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 02/25] netfilter: conntrack: fix race between nf_conntrack proc read and hash resize Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 03/25] netfilter: cttimeout: unlink timeout obj again when hash resize happen Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 04/25] netfilter: nf_ct_helper: unlink helper " Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 05/25] netfilter: conntrack: simplify early_drop Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 06/25] netfilter: move nat hlist_head to nf_conn Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 07/25] netfilter: nat: convert nat bysrc hash to rhashtable Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 08/25] netfilter: physdev: physdev-is-out should not work with OUTPUT chain Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 09/25] netfilter: nft_ct: make byte/packet expr more friendly Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 10/25] netfilter: constify arg to is_dying/confirmed Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 11/25] netfilter: nf_tables: get rid of possible_net_t from set and basechain Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 12/25] netfilter: nf_conntrack_h323: fix off-by-one in DecodeQ931 Pablo Neira Ayuso
2016-07-23 11:08 ` Pablo Neira Ayuso [this message]
2016-07-23 11:08 ` [PATCH 14/25] netfilter: x_tables: speed up jump target validation Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 15/25] netfilter: nft_ct: fix unpaired nf_connlabels_get/put call Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 16/25] netfilter: Add helper array register/unregister functions Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 17/25] netfilter: nft_log: fix possible memory leak if log expr init fail Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 18/25] netfilter: nft_log: check the validity of log level Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 19/25] netfilter: nft_log: fix snaplen does not truncate packets Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 20/25] netfilter: nf_tables: allow to filter out rules by table and chain Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 21/25] netfilter: conntrack: support a fixed size of 128 distinct labels Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 22/25] netfilter: connlabels: move set helper to xt_connlabel Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 23/25] netfilter: h323: Use mod_timer instead of set_expect_timeout Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 24/25] netfilter: nft_compat: put back match/target module if init fail Pablo Neira Ayuso
2016-07-23 11:08 ` [PATCH 25/25] netfilter: nft_compat: fix crash when related match/target module is removed Pablo Neira Ayuso
-- strict thread matches above, loose matches on Subject: below --
2016-07-23 11:02 [PATCH 00/25] Netfilter/IPVS updates for net-next Pablo Neira Ayuso
2016-07-23 11:02 ` [PATCH 13/25] netfilter: conntrack: protect early_drop by rcu read lock Pablo Neira Ayuso
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