Unable to handle kernel NULL pointer dereference

>Description of problem:

After upgrading the the latest legacy kernel, the system freezes after a few hours on production systems.

About 30 hosts have been updated so far, and the problem appeared on two different physical nodes, in less than 24 hours.

>How reproducible:

I do not know how to reproduce it yet.

>Steps to Reproduce:
1. yum update
2. reboot
3. wait

>Actual results:

Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.192601] BUG: unable to handle kernel
Aug 23 05:45:50 NULL pointer dereference
Aug 23 05:45:50 XXX.XXX.XXX.XXX at 0000000000000248
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.193093] IP:
Aug 23 05:45:50 XXX.XXX.XXX.XXX [<ffffffff810d1d11>] ub_sock_tcp_chargerecv+0x21/0x220
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.193377] Kernel PGD 0
Aug 23 05:45:50 XXX.XXX.XXX.XXX
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.193649] User PGD 0
Aug 23 05:45:50 XXX.XXX.XXX.XXX
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.193921] Oops: 0000 [#1]
Aug 23 05:45:50 SMP
Aug 23 05:45:50 XXX.XXX.XXX.XXX
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.194255] last sysfs file: /sys/devices/system/cpu/online
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.194473] CPU 0
Aug 23 05:45:50 XXX.XXX.XXX.XXX
Aug 23 05:45:50 XXX.XXX.XXX.XXX [58451.194538] Modules linked in:
Aug 23 05:45:50 XXX.XXX.XXX.XXX cls_u32
Aug 23 05:45:50 XXX.XXX.XXX.XXX cls_fw
Aug 23 05:45:50 XXX.XXX.XXX.XXX sch_sfq
Aug 23 05:45:50 XXX.XXX.XXX.XXX sch_htb
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_MARK
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip6t_LOG
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_conntrack_ipv6
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_defrag_ipv6
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipt_MASQUERADE
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipt_REDIRECT
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_set
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip_set
Aug 23 05:45:50 XXX.XXX.XXX.XXX nfnetlink
Aug 23 05:45:50 XXX.XXX.XXX.XXX netconsole
Aug 23 05:45:50 XXX.XXX.XXX.XXX configfs
Aug 23 05:45:50 XXX.XXX.XXX.XXX tun
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_conntrack
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzethdev
Aug 23 05:45:50 XXX.XXX.XXX.XXX pio_kaio
Aug 23 05:45:50 XXX.XXX.XXX.XXX pio_nfs
Aug 23 05:45:50 XXX.XXX.XXX.XXX pio_direct
Aug 23 05:45:50 XXX.XXX.XXX.XXX pfmt_raw
Aug 23 05:45:50 XXX.XXX.XXX.XXX pfmt_ploop1
Aug 23 05:45:50 XXX.XXX.XXX.XXX ploop
Aug 23 05:45:50 XXX.XXX.XXX.XXX simfs
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzrst
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzcpt
Aug 23 05:45:50 XXX.XXX.XXX.XXX nfs
Aug 23 05:45:50 XXX.XXX.XXX.XXX lockd
Aug 23 05:45:50 XXX.XXX.XXX.XXX fscache
Aug 23 05:45:50 XXX.XXX.XXX.XXX auth_rpcgss
Aug 23 05:45:50 XXX.XXX.XXX.XXX nfs_acl
Aug 23 05:45:50 XXX.XXX.XXX.XXX sunrpc
Aug 23 05:45:50 XXX.XXX.XXX.XXX vziolimit
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzdquota
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip6t_REJECT
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip6table_mangle
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip6table_filter
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip6_tables
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzevent
Aug 23 05:45:50 XXX.XXX.XXX.XXX vznetdev
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzmon
Aug 23 05:45:50 XXX.XXX.XXX.XXX vzdev
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipv6
Aug 23 05:45:50 XXX.XXX.XXX.XXX sr_mod
Aug 23 05:45:50 XXX.XXX.XXX.XXX cdrom
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_statistic
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_pkttype
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_hashlimit
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_length
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_dscp
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_limit
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_multiport
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_TCPMSS
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_tcpmss
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_hl
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_recent
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_state
Aug 23 05:45:50 XXX.XXX.XXX.XXX xt_connlimit
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipt_REJECT
Aug 23 05:45:50 XXX.XXX.XXX.XXX iptable_filter
Aug 23 05:45:50 XXX.XXX.XXX.XXX iptable_mangle
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipt_LOG
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_conntrack_ftp
Aug 23 05:45:50 XXX.XXX.XXX.XXX iptable_nat
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_nat
Aug 23 05:45:50 XXX.XXX.XXX.XXX ip_tables
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_conntrack_ipv4
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_conntrack
Aug 23 05:45:50 XXX.XXX.XXX.XXX nf_defrag_ipv4
Aug 23 05:45:50 XXX.XXX.XXX.XXX usb_storage
Aug 23 05:45:50 XXX.XXX.XXX.XXX joydev
Aug 23 05:45:50 XXX.XXX.XXX.XXX iTCO_wdt
Aug 23 05:45:50 XXX.XXX.XXX.XXX iTCO_vendor_support
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipmi_devintf
Aug 23 05:45:50 XXX.XXX.XXX.XXX power_meter
Aug 23 05:45:50 XXX.XXX.XXX.XXX acpi_ipmi
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipmi_si
Aug 23 05:45:50 XXX.XXX.XXX.XXX ipmi_msghandler
Aug 23 05:45:50 XXX.XXX.XXX.XXX sb_edac
Aug 23 05:45:50 XXX.XXX.XXX.XXX edac_core
Aug 23 05:45:50 XXX.XXX.XXX.XXX i2c_i801
Aug 23 05:45:50 XXX.XXX.XXX.XXX sg
Aug 23 05:45:50 XXX.XXX.XXX.XXX lpc_ich
Aug 23 05:45:50 XXX.XXX.XXX.XXX mfd_core
Aug 23 05:45:50 XXX.XXX.XXX.XXX shpchp
Aug 23 05:45:50 XXX.XXX.XXX.XXX igb
Aug 23 05:45:50 XXX.XXX.XXX.XXX dca
Aug 23 05:45:50 XXX.XXX.XXX.XXX i2c_algo_bit
Aug 23 05:45:50 XXX.XXX.XXX.XXX i2c_core
Aug 23 05:45:50 XXX.XXX.XXX.XXX ptp
Aug 23 05:45:50 XXX.XXX.XXX.XXX pps_core
Aug 23 05:45:50 XXX.XXX.XXX.XXX ext4
Aug 23 05:45:50 XXX.XXX.XXX.XXX jbd2
Aug 23 05:45:50 XXX.XXX.XXX.XXX mbcache
Aug 23 05:45:50 XXX.XXX.XXX.XXX raid456
Aug 23 05:45:50 XXX.XXX.XXX.XXX async_raid6_recov
Aug 23 05:45:50 XXX.XXX.XXX.XXX async_pq
Aug 23 05:45:50 XXX.XXX.XXX.XXX raid6_pq
Aug 23 05:45:50 XXX.XXX.XXX.XXX async_xor
Aug 23 05:45:50 XXX.XXX.XXX.XXX xor
Aug 23 05:45:50 XXX.XXX.XXX.XXX async_memcpy
Aug 23 05:45:50 XXX.XXX.XXX.XXX async_tx
Aug 23 05:45:50 XXX.XXX.XXX.XXX raid10
Aug 23 05:45:50 XXX.XXX.XXX.XXX sd_mod
Aug 23 05:45:51 XXX.XXX.XXX.XXX crc_t10dif
Aug 23 05:45:51 XXX.XXX.XXX.XXX xhci_hcd
Aug 23 05:45:51 XXX.XXX.XXX.XXX ahci
Aug 23 05:45:51 XXX.XXX.XXX.XXX wmi
Aug 23 05:45:51 XXX.XXX.XXX.XXX dm_mirror
Aug 23 05:45:51 XXX.XXX.XXX.XXX dm_region_hash
Aug 23 05:45:51 XXX.XXX.XXX.XXX dm_log
Aug 23 05:45:51 XXX.XXX.XXX.XXX dm_mod
Aug 23 05:45:51 XXX.XXX.XXX.XXX [last unloaded: netconsole]
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.204133]
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.204343] Pid: 0, comm: swapper veid: 0 Not tainted 2.6.32-042stab133.1 #1 042stab133
Aug 23 05:45:51 XXX.XXX.XXX.XXX Supermicro Super Server
Aug 23 05:45:51 XXX.XXX.XXX.XXX /X10SRi-F
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.204898] RIP: 0010:[<ffffffff810d1d11>]
Aug 23 05:45:51 XXX.XXX.XXX.XXX [<ffffffff810d1d11>] ub_sock_tcp_chargerecv+0x21/0x220
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.205328] RSP: 0018:ffff880028203960 EFLAGS: 00010286
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.205545] RAX: ffff8815cf105ac0 RBX: 0000000000000000 RCX: 0000000000000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.205768] RDX: 0000000000000002 RSI: ffff8815cf105ac0 RDI: 0000000000000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.205989] RBP: ffff8800282039a0 R08: ffff88154bc1eec0 R09: 00000000a0042000
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.206210] R10: 0000000000000001 R11: 0000000000000000 R12: ffff8813e370a1c0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.206431] R13: 000000002fe89720 R14: ffff8815cf105ac0 R15: 0000000000000e80
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.206653] FS: 0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.207020] CS: 0010 DS: 0018 ES: 0018 CR0: 0000000080050033
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.207238] CR2: 0000000000000248 CR3: 00000018578fe000 CR4: 00000000001607f0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.207459] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.207680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.207902] Process swapper (pid: 0, veid: 0, threadinfo ffffffff81a00000, task ffffffff81a97020)
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.208271] Stack:
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.208481] ffff8800ffffffff
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff881873e3f300
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff880080000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX 0000000000000000
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.208883] <d>
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff8813e370a1c0
Aug 23 05:45:51 XXX.XXX.XXX.XXX 000000002fe89720
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff8815cf105ac0
Aug 23 05:45:51 XXX.XXX.XXX.XXX 0000000000000e80
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.209550] <d>
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff880028203a50
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffffffff814edc73
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff881873760200
Aug 23 05:45:51 XXX.XXX.XXX.XXX ffff880028203a00
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.210422] Call Trace:
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.210633] <IRQ>
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.210908] [<ffffffff814edc73>] tcp_collapse+0x213/0x400
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.211130] [<ffffffffa02f4302>] ? nf_nat_get_offset+0x62/0xa0 [nf_nat]
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.211351] [<ffffffff814ee10f>] tcp_try_rmem_schedule+0x2af/0x3d0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.211571] [<ffffffff814ee600>] tcp_data_queue+0x3d0/0xcd0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.211790] [<ffffffff814ef0b0>] ? tcp_validate_incoming+0x1b0/0x320
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.212010] [<ffffffff814f1d19>] tcp_rcv_established+0x3d9/0x860
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.212230] [<ffffffff814fae5b>] tcp_v4_do_rcv+0x31b/0x4d0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.212450] [<ffffffffa02fd471>] ? nf_nat_fn+0x91/0x270 [iptable_nat]
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.212670] [<ffffffff814fd38a>] tcp_v4_rcv+0x54a/0x9a0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.212888] [<ffffffff81500ef8>] ? raw_local_deliver+0x48/0x250
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.213108] [<ffffffff814d7579>] ip_local_deliver_finish+0x129/0x320
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.213328] [<ffffffff814d7808>] ip_local_deliver+0x98/0xa0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.213546] [<ffffffff814d6c43>] ip_rcv_finish+0x133/0x460
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.213764] [<ffffffff814d71f7>] ip_rcv+0x287/0x370
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.213983] [<ffffffff8149989a>] __netif_receive_skb+0x24a/0x600
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.214202] [<ffffffff81499cea>] process_backlog+0x9a/0x100
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.214421] [<ffffffff8149f3e6>] net_rx_action+0x116/0x330
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.214640] [<ffffffff81090bea>] __do_softirq+0x12a/0x2b0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.214861] [<ffffffff815719cc>] call_softirq+0x1c/0x30
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.215081] [<ffffffff8100eb85>] do_softirq+0x65/0xa0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.215298] [<ffffffff810907f5>] irq_exit+0xd5/0xe0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.215515] [<ffffffff815728ee>] smp_apic_timer_interrupt+0x4e/0x60
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.215735] [<ffffffff815711c3>] apic_timer_interrupt+0x13/0x20
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.215953] <EOI>
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.216225] [<ffffffff81460b09>] ? poll_idle+0x49/0x90
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.216442] [<ffffffff81460add>] ? poll_idle+0x1d/0x90
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.216660] [<ffffffff81460cde>] cpuidle_idle_call+0x8e/0xf0
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.216879] [<ffffffff8100a179>] cpu_idle+0xb9/0x110
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.217097] [<ffffffff8154b6c5>] rest_init+0x85/0x90
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.217316] [<ffffffff81c4d2a6>] start_kernel+0x33b/0x33d
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.217534] [<ffffffff81c4c383>] x86_64_start_reservations+0x81/0x85
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.217755] [<ffffffff81c4c47f>] x86_64_start_kernel+0xd6/0xe5
Aug 23 05:45:51 XXX.XXX.XXX.XXX [58451.217974] Code:
Aug 23 05:45:51 66
Aug 23 05:45:51 2e
Aug 23 05:45:51 0f
Aug 23 05:45:51 1f
Aug 23 05:45:51 84
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 55
Aug 23 05:45:51 48
Aug 23 05:45:51 89
Aug 23 05:45:51 e5
Aug 23 05:45:51 48
Aug 23 05:45:51 83
Aug 23 05:45:51 ec
Aug 23 05:45:51 40
Aug 23 05:45:51 48
Aug 23 05:45:51 89
Aug 23 05:45:51 5d
Aug 23 05:45:51 d8
Aug 23 05:45:51 4c
Aug 23 05:45:51 89
Aug 23 05:45:51 65
Aug 23 05:45:51 e0
Aug 23 05:45:51 4c
Aug 23 05:45:51 89
Aug 23 05:45:51 6d
Aug 23 05:45:51 e8
Aug 23 05:45:51 4c
Aug 23 05:45:51 89
Aug 23 05:45:51 75
Aug 23 05:45:51 f0
Aug 23 05:45:51 4c
Aug 23 05:45:51 89
Aug 23 05:45:51 7d
Aug 23 05:45:51 f8
Aug 23 05:45:51 0f
Aug 23 05:45:51 1f
Aug 23 05:45:51 44
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 XXX.XXX.XXX.XXX
Aug 23 05:45:51 83
Aug 23 05:45:51 bf
Aug 23 05:45:51 48
Aug 23 05:45:51 02
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 00
Aug 23 05:45:51 myhost kernel: [58451.192601] BUG: unable to handle kernel NULL pointer dereference at 0000000000000248

>Expected results:

I expect the system not to freeze ;)

>Host OS:

CentOS release 6.10
vzkernel 2.6.32-042stab133.1 from openvz repo
vzctl version 4.11.1

## Global parameters
VIRTUOZZO=yes
LOCKDIR=/vz/lock
DUMPDIR=/vz/dump
VE0CPUUNITS=1000
VE_LAYOUT=simfs

## Logging parameters
LOGGING=yes
LOGFILE=/var/log/vzctl.log
LOG_LEVEL=0
VERBOSE=0

## Disk quota parameters
DISK_QUOTA=yes

## Parametre demarrage
VZFASTBOOT=yes
VE_STOP_MODE=stop


# Disable module loading. If set, vz initscript does not load any modules.
#MODULES_DISABLED=yes

# The name of the device whose IP address will be used as source IP for CT.
# By default automatically assigned.
#VE_ROUTE_SRC_DEV="eth0"

# Controls which interfaces to send ARP requests and modify APR tables on.
NEIGHBOUR_DEVS=all

## Fail if there is another machine in the network with the same IP
ERROR_ON_ARPFAIL="no"

## Template parameters
TEMPLATE=/vz/template

## Defaults for containers
VE_ROOT=/vz/root/$VEID
VE_PRIVATE=/vz/private/$VEID
CONFIGFILE="basic"
DEF_OSTEMPLATE="centos-5"

## Load vzwdog module
VZWDOG="no"

## IPv4 iptables kernel modules to be enabled in CTs by default
IPTABLES="ipt_REJECT ipt_tos ipt_limit ipt_multiport iptable_filter iptable_mangle ipt_TCPMSS ipt_tcpmss ipt_ttl ipt_length"
## IPv4 iptables kernel modules to be loaded by init.d/vz script
IPTABLES_MODULES="$IPTABLES"

## Enable IPv6
IPV6="yes"

## IPv6 ip6tables kernel modules
IP6TABLES="ip6_tables ip6table_filter ip6table_mangle ip6t_REJECT"
SKIP_SYSCTL_SETUP=yes

>Guest OS:

10 to 60 various operating systems, mostly Debian, CentOS, Ubuntu. Most of them runs web hosting services.

>Additional info (see https://openvz.org/Reporting_OpenVZ_problem):