kernel panic in igb driver

[Nomad Esst]

During some performance tests and while a voice call was going through an igb interface, we attempt to disconnect and connect the cable. After the interface comes up this kernel panic occurs:
Fatal trap 12: page fault while in kernel mode
cpuid = 0; apic id = 00
fault virtual address   = 0xc
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff80e189b9
stack pointer           = 0x28:0xffffff80ba3fe640
frame pointer           = 0x28:0xffffff80ba3feb20
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = interrupt enabled, resume, IOPL = 0
current process         = 12 (irq268: +)
[ thread pid 12 tid 100114 ]
Stopped at      igb_start_locked+0x639:       movzbl  0xc(%rbx),%esi
Thanks in advance.