[PATCH 0/2] ipvs fixes for 3.5

[PATCH 0/2] ipvs fixes for 3.5

[pablo]

From: Pablo Neira Ayuso <pablo@netfilter.org>

Hi David,

I know that we're in fairly late stage to request pulls, but the IPVS people
pinged me with little patches with oops fixes last week.

One of them was recently introduced (during the 3.4 development cycle) while
cleaning up the IPVS netns support. They are:

* Fix one regression introduced in 3.4 while cleaning up the
  netns support for IPVS, from Julian Anastasov.

* Fix one oops triggered due to resetting the conntrack attached to the skb
  instead of just putting it in the forward hook, from Lin Ming. This problem
  seems to be there since 2.6.37 according to Simon Horman.

You can pull these changes from:

git://1984.lsi.us.es/nf master

Thanks!

Julian Anastasov (1):
  ipvs: fix oops in ip_vs_dst_event on rmmod

Lin Ming (1):
  ipvs: fix oops on NAT reply in br_nf context

 include/net/ip_vs.h            |    2 +-
 net/netfilter/ipvs/ip_vs_ctl.c |    5 +++--
 2 files changed, 4 insertions(+), 3 deletions(-)

--
1.7.10

[PATCH 1/2] ipvs: fix oops on NAT reply in br_nf context

[pablo]

From: Lin Ming <mlin@ss.pku.edu.cn>

IPVS should not reset skb->nf_bridge in FORWARD hook
by calling nf_reset for NAT replies. It triggers oops in
br_nf_forward_finish.

[  579.781508] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
[  579.781669] IP: [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.781792] PGD 218f9067 PUD 0
[  579.781865] Oops: 0000 [#1] SMP
[  579.781945] CPU 0
[  579.781983] Modules linked in:
[  579.782047]
[  579.782080]
[  579.782114] Pid: 4644, comm: qemu Tainted: G        W    3.5.0-rc5-00006-g95e69f9 #282 Hewlett-Packard  /30E8
[  579.782300] RIP: 0010:[<ffffffff817b1ca5>]  [<ffffffff817b1ca5>] br_nf_forward_finish+0x58/0x112
[  579.782455] RSP: 0018:ffff88007b003a98  EFLAGS: 00010287
[  579.782541] RAX: 0000000000000008 RBX: ffff8800762ead00 RCX: 000000000001670a
[  579.782653] RDX: 0000000000000000 RSI: 000000000000000a RDI: ffff8800762ead00
[  579.782845] RBP: ffff88007b003ac8 R08: 0000000000016630 R09: ffff88007b003a90
[  579.782957] R10: ffff88007b0038e8 R11: ffff88002da37540 R12: ffff88002da01a02
[  579.783066] R13: ffff88002da01a80 R14: ffff88002d83c000 R15: ffff88002d82a000
[  579.783177] FS:  0000000000000000(0000) GS:ffff88007b000000(0063) knlGS:00000000f62d1b70
[  579.783306] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  579.783395] CR2: 0000000000000004 CR3: 00000000218fe000 CR4: 00000000000027f0
[  579.783505] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  579.783684] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  579.783795] Process qemu (pid: 4644, threadinfo ffff880021b20000, task ffff880021aba760)
[  579.783919] Stack:
[  579.783959]  ffff88007693cedc ffff8800762ead00 ffff88002da01a02 ffff8800762ead00
[  579.784110]  ffff88002da01a02 ffff88002da01a80 ffff88007b003b18 ffffffff817b26c7
[  579.784260]  ffff880080000000 ffffffff81ef59f0 ffff8800762ead00 ffffffff81ef58b0
[  579.784477] Call Trace:
[  579.784523]  <IRQ>
[  579.784562]
[  579.784603]  [<ffffffff817b26c7>] br_nf_forward_ip+0x275/0x2c8
[  579.784707]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.784797]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.784906]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.784995]  [<ffffffff817ac32e>] ? br_dev_queue_push_xmit+0xae/0xae
[  579.785175]  [<ffffffff8187fa95>] ? _raw_write_unlock_bh+0x19/0x1b
[  579.785179]  [<ffffffff817ac417>] __br_forward+0x97/0xa2
[  579.785179]  [<ffffffff817ad366>] br_handle_frame_finish+0x1a6/0x257
[  579.785179]  [<ffffffff817b2386>] br_nf_pre_routing_finish+0x26d/0x2cb
[  579.785179]  [<ffffffff817b2cf0>] br_nf_pre_routing+0x55d/0x5c1
[  579.785179]  [<ffffffff81704b58>] nf_iterate+0x47/0x7d
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81704bfb>] nf_hook_slow+0x6d/0x102
[  579.785179]  [<ffffffff817ad1c0>] ? br_handle_local_finish+0x44/0x44
[  579.785179]  [<ffffffff81551525>] ? sky2_poll+0xb35/0xb54
[  579.785179]  [<ffffffff817ad62a>] br_handle_frame+0x213/0x229
[  579.785179]  [<ffffffff817ad417>] ? br_handle_frame_finish+0x257/0x257
[  579.785179]  [<ffffffff816e3b47>] __netif_receive_skb+0x2b4/0x3f1
[  579.785179]  [<ffffffff816e69fc>] process_backlog+0x99/0x1e2
[  579.785179]  [<ffffffff816e6800>] net_rx_action+0xdf/0x242
[  579.785179]  [<ffffffff8107e8a8>] __do_softirq+0xc1/0x1e0
[  579.785179]  [<ffffffff8135a5ba>] ? trace_hardirqs_off_thunk+0x3a/0x6c
[  579.785179]  [<ffffffff8188812c>] call_softirq+0x1c/0x30

The steps to reproduce as follow,

1. On Host1, setup brige br0(192.168.1.106)
2. Boot a kvm guest(192.168.1.105) on Host1 and start httpd
3. Start IPVS service on Host1
   ipvsadm -A -t 192.168.1.106:80 -s rr
   ipvsadm -a -t 192.168.1.106:80 -r 192.168.1.105:80 -m
4. Run apache benchmark on Host2(192.168.1.101)
   ab -n 1000 http://192.168.1.106/

ip_vs_reply4
  ip_vs_out
    handle_response
      ip_vs_notrack
        nf_reset()
        {
          skb->nf_bridge = NULL;
        }

Actually, IPVS wants in this case just to replace nfct
with untracked version. So replace the nf_reset(skb) call
in ip_vs_notrack() with a nf_conntrack_put(skb->nfct) call.

Signed-off-by: Lin Ming <mlin@ss.pku.edu.cn>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 include/net/ip_vs.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index d6146b4..95374d1 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -1425,7 +1425,7 @@ static inline void ip_vs_notrack(struct sk_buff *skb)
 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
 
 	if (!ct || !nf_ct_is_untracked(ct)) {
-		nf_reset(skb);
+		nf_conntrack_put(skb->nfct);
 		skb->nfct = &nf_ct_untracked_get()->ct_general;
 		skb->nfctinfo = IP_CT_NEW;
 		nf_conntrack_get(skb->nfct);
-- 
1.7.10

[PATCH 2/2] ipvs: fix oops in ip_vs_dst_event on rmmod

[pablo]

From: Julian Anastasov <ja@ssi.bg>

	After commit 39f618b4fd95ae243d940ec64c961009c74e3333 (3.4)
"ipvs: reset ipvs pointer in netns" we can oops in
ip_vs_dst_event on rmmod ip_vs because ip_vs_control_cleanup
is called after the ipvs_core_ops subsys is unregistered and
net->ipvs is NULL. Fix it by exiting early from ip_vs_dst_event
if ipvs is NULL. It is safe because all services and dests
for the net are already freed.

Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/ipvs/ip_vs_ctl.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index d43e3c1..84444dd 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -1521,11 +1521,12 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
 {
 	struct net_device *dev = ptr;
 	struct net *net = dev_net(dev);
+	struct netns_ipvs *ipvs = net_ipvs(net);
 	struct ip_vs_service *svc;
 	struct ip_vs_dest *dest;
 	unsigned int idx;
 
-	if (event != NETDEV_UNREGISTER)
+	if (event != NETDEV_UNREGISTER || !ipvs)
 		return NOTIFY_DONE;
 	IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
 	EnterFunction(2);
@@ -1551,7 +1552,7 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
 		}
 	}
 
-	list_for_each_entry(dest, &net_ipvs(net)->dest_trash, n_list) {
+	list_for_each_entry(dest, &ipvs->dest_trash, n_list) {
 		__ip_vs_dev_reset(dest, dev);
 	}
 	mutex_unlock(&__ip_vs_mutex);
-- 
1.7.10

Re: [PATCH 0/2] ipvs fixes for 3.5

[David Miller]

From: pablo@netfilter.org
Date: Tue, 17 Jul 2012 12:06:27 +0200

> I know that we're in fairly late stage to request pulls, but the IPVS people
> pinged me with little patches with oops fixes last week.
> 
> One of them was recently introduced (during the 3.4 development cycle) while
> cleaning up the IPVS netns support. They are:
> 
> * Fix one regression introduced in 3.4 while cleaning up the
>   netns support for IPVS, from Julian Anastasov.
> 
> * Fix one oops triggered due to resetting the conntrack attached to the skb
>   instead of just putting it in the forward hook, from Lin Ming. This problem
>   seems to be there since 2.6.37 according to Simon Horman.
> 
> You can pull these changes from:
> 
> git://1984.lsi.us.es/nf master

Pulled, thanks Pablo.