This is a note to let you know that I've just added the patch titled
netfilter: nf_nat: fix race when unloading protocol modules
to the 3.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-nf_nat-fix-race-when-unloading-protocol-modules.patch
and it can be found in the queue-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c2d421e171868586939c328dfb91bab840fe4c49 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@xxxxxxxxx>
Date: Thu, 11 Apr 2013 04:22:39 +0000
Subject: netfilter: nf_nat: fix race when unloading protocol modules
From: Florian Westphal <fw@xxxxxxxxx>
commit c2d421e171868586939c328dfb91bab840fe4c49 upstream.
following oops was reported:
RIP: 0010:[<ffffffffa03227f2>] [<ffffffffa03227f2>] nf_nat_cleanup_conntrack+0x42/0x70 [nf_nat]
RSP: 0018:ffff880202c63d40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8801ac7bec28 RCX: ffff8801d0eedbe0
RDX: dead000000200200 RSI: 0000000000000011 RDI: ffffffffa03265b8
[..]
Call Trace:
[..]
[<ffffffffa02febed>] destroy_conntrack+0xbd/0x110 [nf_conntrack]
Happens when a conntrack timeout expires right after first part
of the nat cleanup has completed (bysrc hash removal), but before
part 2 has completed (re-initialization of nat area).
[ destroy callback tries to delete bysrc again ]
Patrick suggested to just remove the affected conntracks -- the
connections won't work properly anyway without nat transformation.
So, lets do that.
Reported-by: CAI Qian <caiqian@xxxxxxxxxx>
Cc: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Acked-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/nf_nat_core.c | 40 +++++++---------------------------------
1 file changed, 7 insertions(+), 33 deletions(-)
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -468,33 +468,22 @@ EXPORT_SYMBOL_GPL(nf_nat_packet);
struct nf_nat_proto_clean {
u8 l3proto;
u8 l4proto;
- bool hash;
};
-/* Clear NAT section of all conntracks, in case we're loaded again. */
-static int nf_nat_proto_clean(struct nf_conn *i, void *data)
+/* kill conntracks with affected NAT section */
+static int nf_nat_proto_remove(struct nf_conn *i, void *data)
{
const struct nf_nat_proto_clean *clean = data;
struct nf_conn_nat *nat = nfct_nat(i);
if (!nat)
return 0;
- if (!(i->status & IPS_SRC_NAT_DONE))
- return 0;
+
if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
(clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
return 0;
- if (clean->hash) {
- spin_lock_bh(&nf_nat_lock);
- hlist_del_rcu(&nat->bysource);
- spin_unlock_bh(&nf_nat_lock);
- } else {
- memset(nat, 0, sizeof(*nat));
- i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK |
- IPS_SEQ_ADJUST);
- }
- return 0;
+ return i->status & IPS_NAT_MASK ? 1 : 0;
}
static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
@@ -506,16 +495,8 @@ static void nf_nat_l4proto_clean(u8 l3pr
struct net *net;
rtnl_lock();
- /* Step 1 - remove from bysource hash */
- clean.hash = true;
for_each_net(net)
- nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
- synchronize_rcu();
-
- /* Step 2 - clean NAT section */
- clean.hash = false;
- for_each_net(net)
- nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+ nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean);
rtnl_unlock();
}
@@ -527,16 +508,9 @@ static void nf_nat_l3proto_clean(u8 l3pr
struct net *net;
rtnl_lock();
- /* Step 1 - remove from bysource hash */
- clean.hash = true;
- for_each_net(net)
- nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
- synchronize_rcu();
- /* Step 2 - clean NAT section */
- clean.hash = false;
for_each_net(net)
- nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+ nf_ct_iterate_cleanup(net, nf_nat_proto_remove, &clean);
rtnl_unlock();
}
@@ -774,7 +748,7 @@ static void __net_exit nf_nat_net_exit(s
{
struct nf_nat_proto_clean clean = {};
- nf_ct_iterate_cleanup(net, &nf_nat_proto_clean, &clean);
+ nf_ct_iterate_cleanup(net, &nf_nat_proto_remove, &clean);
synchronize_rcu();
nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size);
}
Patches currently in stable-queue which might be from fw@xxxxxxxxx are
queue-3.8/netfilter-ctnetlink-don-t-permit-ct-creation-with-random-tuple.patch
queue-3.8/netfilter-xt_rpfilter-skip-locally-generated-broadcast-multicast-too.patch
queue-3.8/netfilter-nf_nat-fix-race-when-unloading-protocol-modules.patch
queue-3.8/netfilter-nf_ct_helper-don-t-discard-helper-if-it-is-actually-the-same.patch
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