Description of problem:
After run 2.6.32-71.18.2 kernel for 42+ hours on a squid server, we observed a kernel oops related t network.

Version-Release number of selected component (if applicable):
2.6.32-71.18.2 on X86_64, we rebild this kernel from srpm and run it on RHEL5 installation.

How reproducible:
Not sure how to reproduce, just run squid workload on the server, after 42+ hours, we observed this oops from log. Didn't find similar oops on other machines.

Steps to Reproduce:
1. run squid workload
2. around 42+ hours
3. only observe onece
  
Actual results:
So far it seems the system will working

Expected results:
Maybe the kernel oops should not be there. 

Additional info:
Attaching the oops info, please note the kernel is running on RHEL5.

[152286.466138] ------------[ cut here ]------------
[152286.472442] WARNING: at net/ipv4/tcp_input.c:2919 tcp_ack+0xc9b/0x168d() (Not tainted)
[152286.482689] Hardware name: CS24-TY
[152286.488837] Modules linked in: ext2 bonding ipv6 dm_mirror dm_multipath video output sbs sbshc power_meter hwmon acpi_pad parport sg igb serio_raw i7core_edac 

iTCO_wdt dcdbas iTCO_vendor_support ahci i2c_i801 edac_core ioatdma dca dm_region_hash dm_log dm_mod megaraid_sas shpchp mptsas mptscsih mptbase scsi_transport_sas 

uhci_hcd ohci_hcd ehci_hcd
[152286.531076] Pid: 0, comm: swapper Not tainted 2.6.32-71.18.2.el5.x86_64 #1
[152286.541169] Call Trace:
[152286.544388]  <IRQ>  [<ffffffff81405e32>] ? tcp_ack+0xc9b/0x168d
[152286.552189]  [<ffffffff8105b94b>] warn_slowpath_common+0x8d/0xa6
[152286.560651]  [<ffffffff8105b97e>] warn_slowpath_null+0x1a/0x1c
[152286.568640]  [<ffffffff81405e32>] tcp_ack+0xc9b/0x168d
[152286.575413]  [<ffffffff81407aa0>] tcp_rcv_established+0xcd/0x566
[152286.583163]  [<ffffffff8140df6b>] tcp_v4_do_rcv+0x196/0x352
[152286.591026]  [<ffffffff8106260a>] ? local_bh_enable+0x12/0x14
[152286.599189]  [<ffffffff8140f628>] tcp_v4_rcv+0x423/0x631
[152286.606234]  [<ffffffff813f3831>] ? ip_local_deliver_finish+0x152/0x1fa
[152286.614716]  [<ffffffff813f3831>] ip_local_deliver_finish+0x152/0x1fa
[152286.623599]  [<ffffffff813f3c2c>] ip_local_deliver+0x72/0x7d
[152286.630793]  [<ffffffff813f365d>] ip_rcv_finish+0x371/0x38b
[152286.638677]  [<ffffffff8140ce7f>] ? tcp4_gro_receive+0x9b/0xa4
[152286.646744]  [<ffffffff813f3b7b>] ip_rcv+0x2a2/0x2e1
[152286.653612]  [<ffffffff813cb9c8>] netif_receive_skb+0x448/0x47f
[152286.661247]  [<ffffffff813cba9b>] napi_skb_finish+0x2b/0x43
[152286.668123]  [<ffffffff813cbf14>] napi_gro_receive+0x2f/0x34
[152286.675784]  [<ffffffffa00ea52d>] igb_poll+0x83f/0xba3 [igb]
[152286.681994]  [<ffffffff810181f0>] ? read_tsc+0xd/0x25
[152286.687392]  [<ffffffff81082c9e>] ? timekeeping_get_ns+0x1b/0x3d
[152286.693952]  [<ffffffff8104b406>] ? __enqueue_entity+0x79/0x7b
[152286.700285]  [<ffffffff810624cd>] ? local_bh_enable_ip+0xe/0x10
[152286.706609]  [<ffffffff813ced7c>] net_rx_action+0xc6/0x1c3
[152286.712561]  [<ffffffff81062a2d>] __do_softirq+0xd2/0x194
[152286.718323]  [<ffffffff810b646c>] ? handle_IRQ_event+0x66/0x120
[152286.724614]  [<ffffffff81012e8c>] call_softirq+0x1c/0x30
[152286.730296]  [<ffffffff81014757>] do_softirq+0x46/0x87
[152286.735789]  [<ffffffff810628b5>] irq_exit+0x3b/0x7a
[152286.741110]  [<ffffffff814668e1>] do_IRQ+0x99/0xb0
[152286.746259]  [<ffffffff81012693>] ret_from_intr+0x0/0x11
[152286.751927]  <EOI>  [<ffffffff812ba90c>] ? acpi_idle_enter_bm+0x232/0x267
[152286.759123]  [<ffffffff812ba905>] ? acpi_idle_enter_bm+0x22b/0x267
[152286.765697]  [<ffffffff813a1b75>] ? menu_select+0x15a/0x228
[152286.771655]  [<ffffffff813a0d55>] cpuidle_idle_call+0x87/0xe2
[152286.777799]  [<ffffffff81010c68>] cpu_idle+0xa5/0xd4
[152286.783111]  [<ffffffff8145c26f>] ? start_secondary+0x1ea/0x237
[152286.789402]  [<ffffffff8145c27d>] start_secondary+0x1f8/0x237
[152286.795536] ---[ end trace 23becf1ca0e310bc ]---