Exact Kernel version: 2.5.52
Hardware Environment: NUMA-Q

On shutdown, I seem to intermittently get the following panic:

Saving random seed... done.
Unmounting remote filesystems... Unable to handle kernel NULL pointer dereferenc
e at virtual address 00000504
 printing eip:
c012e5d0
*pde = 00104001
*pte = 00000000
Oops: 0002
CPU:    15
EIP:    0060:[<c012e5d0>]    Not tainted
EFLAGS: 00010046
EIP is at __pdflush+0x30/0x1e8
eax: 00000000   ebx: ede14000   ecx: eeff2d64   edx: eeff2cc0
esi: c020bcf4   edi: eeff2fae   ebp: ede15fd8   esp: ede15fc0
ds: 0068   es: 0068   ss: 0068
Process pdflush (pid: 4033, threadinfo=ede14000 task=eeff2cc0)
Stack: c012e788 00000000 00000000 00000000 c012e793 ede15fd8 00000000 00000000 
       00000068 00000068 ffffffff c0106e7c c0106e81 00000000 00000000 00000000 
Call Trace:
 [<c012e788>] pdflush+0x0/0x14
 [<c012e793>] pdflush+0xb/0x14
 [<c0106e7c>] kernel_thread_helper+0x0/0xc
 [<c0106e81>] kernel_thread_helper+0x5/0xc

Code: f0 fe 88 04 05 00 00 0f 88 60 02 00 00 8b 03 c7 80 a0 05 00 
 <1>Unable to handle kernel NULL pointer dereference at virtual address 0000051c
 printing eip:
c011c3e3
*pde = 2f664001
*pte = 00000000
Oops: 0000
CPU:    10
EIP:    0060:[<c011c3e3>]    Not tainted
EFLAGS: 00010286
EIP is at sys_wait4+0x23b/0x418
eax: 00000008   ebx: 00000000   ecx: 00000000   edx: 00000008
esi: eeff2cc0   edi: f018e0dc   ebp: f0198000   esp: f0199f7c
ds: 0068   es: 0068   ss: 0068
Process init (pid: 1, threadinfo=f0198000 task=f018e040)
Stack: f0198000 00000000 bffff750 bffff714 f0198000 00000001 f018e040 00000000 
       f018e040 c0116d88 00000000 00000000 00000000 f018e040 c0116d88 f018e194 
       f018e194 c0108a27 ffffffff bffff750 00000001 00000000 bffff750 bffff714 
Call Trace:
 [<c0116d88>] default_wake_function+0x0/0x34
 [<c0116d88>] default_wake_function+0x0/0x34
 [<c0108a27>] syscall_call+0x7/0xb

Code: 83 b9 1c 05 00 00 00 74 2a 8b 54 24 4c 83 c2 04 19 c0 39 55 
 <0>Kernel panic: Attempted to kill init!