4.8-stable kernel panic

[sysadmin at wvths.com]

>
> Hi,
>
>> #0  dumpsys () at ../../kern/kern_shutdown.c:487
>> #1  0xc0168237 in boot (howto=256) at ../../kern/kern_shutdown.c:316
>> #2  0xc0168675 in panic (fmt=0xc02db260 "m_copydata, offset > size of
>> mbuf
>> chain") at ../../kern/kern_shutdown.c:595
>> #3  0xc018576e in m_copydata (m=0xc1560d00, off=6144, len=2048,
>> cp=0xc155a800 "") at ../../kern/uipc_mbuf.c:979
>> #4  0xc0186776 in m_defrag (m0=0xc1560d00, how=1) at
>> ../../kern/uipc_mbuf.c:1572
>> #5  0xc021de70 in dc_encap (sc=0xc21c3000, m_head=0xc1560d00,
>> txidx=0xd72d9f60) at ../../pci/if_dc.c:3006
>> #6  0xc021e0bb in dc_start (ifp=0xc21c3000) at ../../pci/if_dc.c:3105
>> #7  0xc021de09 in dc_intr (arg=0xc21c3000) at ../../pci/if_dc.c:2970
>
> This doesn't help me at all. Looks like corrupted mbufs, this doesn't
> have to be in the if_dc driver itself.
>
> So how can you reproduce this panic, is it a fresh panic at all, or
> did you encounter it since ever ? What kind of card do you have (pciconf
> -lv) ?

I remember first being able to get this panic around the beggining of
August, maybe earlier. Reproduce it using this shell script:
---
#!/bin/bash
while :; do
 ping -f -s 65467 ip_addr &
done
---

Here's the NIC info:
dc0 at pci2:9:0:   class=0x020000 card=0x00ed16ec chip=0x12161113 rev=0x11
hdr=0x00
    vendor   = 'Accton Technology Corporation'
    device   = 'EN5251-Based Fast Ethernet Adapter'
    class    = network
    subclass = ethernet

HTH,