Description of problem:
Did the regression test for BZ 723432 and kernel panic.
Boot 2 guests on 2 hosts separately. The two guests can ping each other.
Then running netserver and netperf on the 2 guests separately. As a result, the host A got panic

Version-Release number of selected component (if applicable):
2.6.32-131.20.1.el6.x86_64

How reproducible:
4-5

Steps to Reproduce:
1.install 2 guests on 2 hosts separately. 
2.Ping between the 2 guests to make sure the guests are reachable
3.Run netserver on guest A
#netserver -6
4.Run netperf client on guest B (UDP_STREAM)
#netperf -6 -H 2001::11 -t UDP_STREAM

details see: https://bugzilla.redhat.com/show_bug.cgi?id=723433#c12
  
Actual results:
panic:
BUG: unable to handle kernel paging request at ffff87ffb3784873
IP: [<ffffffffa0362003>] inet6_rt_notify+0x83/0x150 [ipv6]
PGD 0
Oops: 0002 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 1
Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle iptable_filter ip_tables autofs4 sunrpc cpufreq_ondemand powernow_k8 freq_table bridge stp llc ipv6 dm_mirror dm_region_hash dm_log vhost_net macvtap macvlan tun kvm_amd kvm tg3 microcode serio_raw k8temp amd64_edac_mod edac_core edac_mce_amd e100 mii sg i2c_piix4 shpchp ext4 mbcache jbd2 sd_mod crc_t10dif sr_mod cdrom sata_svw ata_generic pata_acpi pata_serverworks radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core dm_mod [last unloaded: scsi_wait_scan]

Modules linked in: ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_CHECKSUM iptable_mangle iptable_filter ip_tables autofs4 sunrpc cpufreq_ondemand powernow_k8 freq_table bridge stp llc ipv6 dm_mirror dm_region_hash dm_log vhost_net macvtap macvlan tun kvm_amd kvm tg3 microcode serio_raw k8temp amd64_edac_mod edac_core edac_mce_amd e100 mii sg i2c_piix4 shpchp ext4 mbcache jbd2 sd_mod crc_t10dif sr_mod cdrom sata_svw ata_generic pata_acpi pata_serverworks radeon ttm drm_kms_helper drm hwmon i2c_algo_bit i2c_core dm_mod [last unloaded: scsi_wait_scan]
Pid: 2183, comm: qemu-kvm Not tainted 2.6.32-131.20.1.el6.x86_64 #1 empty
RIP: 0010:[<ffffffffa0362003>]  [<ffffffffa0362003>] inet6_rt_notify+0x83/0x150 [ipv6]
RSP: 0018:ffff8800283036b0  EFLAGS: 00010282
RAX: ffff88013a02da80 RBX: ffff880028303830 RCX: 0000000000000000
RDX: ffff880139827000 RSI: 0000000000000020 RDI: ffff88013a02db48
RBP: ffff880028303720 R08: ffff8801391719c0 R09: 0000000000000018
R10: 0000000001000000 R11: ffff880028303830 R12: ffff88013a02da80
R13: ffff880239ed1fd8 R14: 0000000000000000 R15: ffffffff82002a80
FS:  00007fd5b998e700(0000) GS:ffff880028300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff87ffb3784873 CR3: 000000013554f000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process qemu-kvm (pid: 2183, threadinfo ffff880239ed0000, task ffff88023917ea80)
Stack:
 ffff8800283036b8 ffff880139823800 ffffffff8112ef99 0000000000000001
<0> ffff88013b628ec0 ffff88000002d5c0 ffff880000000018 ffff880138c60480
<0> ffffffff8115a20b ffff880139171c80 ffff880138c60480 ffff880138c60590
Call Trace:
 <IRQ>
 [<ffffffff8112ef99>] ? zone_statistics+0x99/0xc0
 [<ffffffff8115a20b>] ? cache_alloc_refill+0x15b/0x240
 [<ffffffffa0365386>] fib6_add+0x2a6/0x6c0 [ipv6]
 [<ffffffff814dd869>] ? _write_unlock_bh+0x19/0x20
 [<ffffffff81429655>] ? neigh_create+0x3f5/0x520
 [<ffffffff8115b1b2>] ? kmem_cache_alloc+0x182/0x190
 [<ffffffffa0361608>] __ip6_ins_rt+0x48/0x70 [ipv6]
 [<ffffffffa0361665>] ip6_ins_rt+0x35/0x40 [ipv6]
 [<ffffffffa0363066>] ip6_pol_route+0x2c6/0x360 [ipv6]
 [<ffffffffa0363139>] ip6_pol_route_input+0x19/0x20 [ipv6]
 [<ffffffffa0386831>] fib6_rule_action+0xd1/0x1f0 [ipv6]
 [<ffffffffa0363120>] ? ip6_pol_route_input+0x0/0x20 [ipv6]
 [<ffffffff8143348d>] fib_rules_lookup+0xbd/0x110
 [<ffffffffa0386985>] fib6_rule_lookup+0x35/0xa0 [ipv6]
 [<ffffffffa0363120>] ? ip6_pol_route_input+0x0/0x20 [ipv6]
 [<ffffffffa03613d1>] ip6_route_input+0xf1/0x120 [ipv6]
 [<ffffffffa0357245>] ip6_rcv_finish+0x35/0x50 [ipv6]
 [<ffffffffa03575e8>] ipv6_rcv+0x388/0x460 [ipv6]
 [<ffffffff8141dc2b>] __netif_receive_skb+0x39b/0x6b0
 [<ffffffff8141ff38>] netif_receive_skb+0x58/0x60
 [<ffffffff8141ff38>] netif_receive_skb+0x58/0x60
 [<ffffffffa03c3418>] br_handle_frame_finish+0x1d8/0x260 [bridge]
 [<ffffffffa03c364a>] br_handle_frame+0x1aa/0x250 [bridge]
 [<ffffffff8141da63>] __netif_receive_skb+0x1d3/0x6b0
 [<ffffffffa0352296>] ? ipv6_gro_receive+0x216/0x2f0 [ipv6]
 [<ffffffff8141ff38>] netif_receive_skb+0x58/0x60
 [<ffffffff81420040>] napi_skb_finish+0x50/0x70
 [<ffffffff81422379>] napi_gro_receive+0x39/0x50
 [<ffffffffa02ad121>] tg3_poll_work+0x6b1/0xdf0 [tg3]
 [<ffffffffa02ad8c4>] tg3_poll+0x64/0x210 [tg3]
 [<ffffffff81056fdf>] ? scheduler_tick+0xdf/0x280
 [<ffffffff81422493>] net_rx_action+0x103/0x2f0
 [<ffffffff8106f681>] __do_softirq+0xc1/0x1d0
 [<ffffffff810d6902>] ? handle_IRQ_event+0x92/0x170
 [<ffffffff8106f6da>] ? __do_softirq+0x11a/0x1d0
 [<ffffffff8100c2cc>] call_softirq+0x1c/0x30
 [<ffffffff8100df05>] do_softirq+0x65/0xa0
 [<ffffffff8106f465>] irq_exit+0x85/0x90
 [<ffffffff814e3115>] do_IRQ+0x75/0xf0
 [<ffffffff8100bad3>] ret_from_intr+0x0/0x11
 <EOI>
 [<ffffffffa02dde3e>] ? kvm_arch_vcpu_ioctl_run+0x39e/0xed0 [kvm]
 [<ffffffffa02dde32>] ? kvm_arch_vcpu_ioctl_run+0x392/0xed0 [kvm]
 [<ffffffffa02c8332>] kvm_vcpu_ioctl+0x522/0x670 [kvm]
 [<ffffffff8100bc8e>] ? apic_timer_interrupt+0xe/0x20
 [<ffffffffa02c7e10>] ? kvm_vcpu_ioctl+0x0/0x670 [kvm]
 [<ffffffff81184fe2>] vfs_ioctl+0x22/0xa0
 [<ffffffff811854aa>] do_vfs_ioctl+0x3aa/0x580
 [<ffffffff81185701>] sys_ioctl+0x81/0xa0
 [<ffffffff8100b172>] system_call_fastpath+0x16/0x1b
Code: 44 89 4d c0 30 c0 66 83 f8 01 19 f6 31 d2 81 e6 b0 00 00 00 83 c6 20 e8 cc 25 0b e1 48 85 c0 49 89 c4 52 54 00 fe 3b 48 7c 00 00 <00> 8b 43 10 48 8b 55 c8 45 31 c0 31 c9 4c 89 e6 4c 89 ff c7 44
RIP  [<ffffffffa0362003>] inet6_rt_notify+0x83/0x150 [ipv6]
 RSP <ffff8800283036b0>
CR2: ffff87ffb3784873


Expected results:
no panic

Additional info:
run in kernel 2.6.32-131.19.1.el6.x86_64 and 2.6.32-131.17.1.el6.x86_64 panic,too