datapath: stt: Do not access stt_dev socket in lookup.

STT device is added to the device list at device create time. and
the dev socket is initialized when dev is UP. So avoid accessing
stt socket while searching a device.

---8<---
IP: [<ffffffffc0e731fd>] nf_ip_hook+0xfd/0x180 [openvswitch]
Oops: 0000 [#1] PREEMPT SMP
Hardware name: VMware, Inc. VMware Virtual Platform/440BX
RIP: 0010:[<ffffffffc0e731fd>]  [<ffffffffc0e731fd>] nf_ip_hook+0xfd/0x180 [openvswitch]
RSP: 0018:ffff88043fd03cd0  EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffff8801008e2200 RCX: 0000000000000034
RDX: 0000000000000110 RSI: ffff8801008e2200 RDI: ffff8801533a3880
RBP: ffff88043fd03d00 R08: ffffffff90646d10 R09: ffff880164b27000
R10: 0000000000000003 R11: ffff880155eb9dd8 R12: 0000000000000028
R13: ffff8802283dc580 R14: 00000000000076b4 R15: ffff880013b20000
FS:  00007ff5ba73b700(0000) GS:ffff88043fd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000020 CR3: 000000037ff96000 CR4: 00000000000007e0
Stack:
 ffff8801533a3890 ffff88043fd03d80 ffffffff90646d10 0000000000000000
 ffff880164b27000 ffff8801008e2200 ffff88043fd03d48 ffffffff9064050a
 ffffffff90d0f930 ffffffffc0e7ef80 0000000000000001 ffff8801008e2200
Call Trace:
 <IRQ>
 [<ffffffff9064050a>] nf_iterate+0x9a/0xb0
 [<ffffffff9064059c>] nf_hook_slow+0x7c/0x120
 [<ffffffff906470f3>] ip_local_deliver+0x73/0x80
 [<ffffffff90646a3d>] ip_rcv_finish+0x7d/0x350
 [<ffffffff90647398>] ip_rcv+0x298/0x3d0
 [<ffffffff9060fc56>] __netif_receive_skb_core+0x696/0x880
 [<ffffffff9060fe58>] __netif_receive_skb+0x18/0x60
 [<ffffffff90610b3e>] process_backlog+0xae/0x180
 [<ffffffff906102c2>] net_rx_action+0x152/0x270
 [<ffffffff9006d625>] __do_softirq+0xf5/0x320
 [<ffffffff9071d15c>] do_softirq_own_stack+0x1c/0x30

Reported-by: Joe Stringer <joe@ovn.org>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Tested-by: Joe Stringer <joe@ovn.org>

diff --git a/datapath/linux/compat/stt.c b/datapath/linux/compat/stt.c
index dcd70ff..1500a76 100644 (file)
--- a/datapath/linux/compat/stt.c
+++ b/datapath/linux/compat/stt.c
@@ -173,7 +173,7 @@ static struct stt_dev *stt_find_sock(struct net *net, __be16 port)
        struct stt_dev *stt_dev;
 
        list_for_each_entry_rcu(stt_dev, &sn->stt_list, next) {
-               if (inet_sk(stt_dev->sock->sk)->inet_sport == port)
+               if (stt_dev->dst_port == port)
                        return stt_dev;
        }
        return NULL;
@@ -934,7 +934,7 @@ netdev_tx_t ovs_stt_xmit(struct sk_buff *skb)
        struct net_device *dev = skb->dev;
        struct stt_dev *stt_dev = netdev_priv(dev);
        struct net *net = stt_dev->net;
-       __be16 dport = inet_sk(stt_dev->sock->sk)->inet_sport;
+       __be16 dport = stt_dev->dst_port;
        struct ip_tunnel_key *tun_key;
        struct ip_tunnel_info *tun_info;
        struct rtable *rt;