From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 4/6] netfilter: tproxy: properly refcount tcp listeners
Date: Thu, 18 Aug 2016 19:29:06 +0200 [thread overview]
Message-ID: <1471541348-1538-5-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1471541348-1538-1-git-send-email-pablo@netfilter.org>
From: Eric Dumazet <edumazet@google.com>
inet_lookup_listener() and inet6_lookup_listener() no longer
take a reference on the found listener.
This minimal patch adds back the refcounting, but we might do
this differently in net-next later.
Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt under synflood")
Reported-and-tested-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_TPROXY.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/netfilter/xt_TPROXY.c b/net/netfilter/xt_TPROXY.c
index 7f4414d..663c4c3 100644
--- a/net/netfilter/xt_TPROXY.c
+++ b/net/netfilter/xt_TPROXY.c
@@ -127,6 +127,8 @@ nf_tproxy_get_sock_v4(struct net *net, struct sk_buff *skb, void *hp,
daddr, dport,
in->ifindex);
+ if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
+ sk = NULL;
/* NOTE: we return listeners even if bound to
* 0.0.0.0, those are filtered out in
* xt_socket, since xt_TPROXY needs 0 bound
@@ -195,6 +197,8 @@ nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, void *hp,
daddr, ntohs(dport),
in->ifindex);
+ if (sk && !atomic_inc_not_zero(&sk->sk_refcnt))
+ sk = NULL;
/* NOTE: we return listeners even if bound to
* 0.0.0.0, those are filtered out in
* xt_socket, since xt_TPROXY needs 0 bound
--
2.1.4
next prev parent reply other threads:[~2016-08-19 0:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-18 17:29 [PATCH 0/6] Netfilter fixes for net Pablo Neira Ayuso
2016-08-18 17:29 ` [PATCH 1/6] netfilter: conntrack: do not dump other netns's conntrack entries via proc Pablo Neira Ayuso
2016-08-18 17:29 ` [PATCH 2/6] netfilter: nfnetlink_log: add "nf-logger-3-1" module alias name Pablo Neira Ayuso
2016-08-18 17:29 ` [PATCH 3/6] netfilter: nfnetlink_acct: report overquota to the right netns Pablo Neira Ayuso
2016-08-18 17:29 ` Pablo Neira Ayuso [this message]
2016-08-18 17:29 ` [PATCH 5/6] netfilter: nfnetlink_acct: fix race between nfacct del and xt_nfacct destroy Pablo Neira Ayuso
2016-08-18 17:29 ` [PATCH 6/6] netfilter: cttimeout: fix use after free error when delete netns Pablo Neira Ayuso
2016-08-19 1:49 ` [PATCH 0/6] Netfilter fixes for net David Miller
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