Description of problem:

I got the following pretty soon after booting to level 3

Unable to handle kernel paging request at virtual address ded60ea4
 printing eip:
c013fc66
*pde = 0001e426
Oops: 0000 [#1]
SMP DEBUG_PAGEALLOC
Modules linked in: loop nfsd exportfs lockd parport_pc lp parport
autofs4 i2c_dev i2c_core sunrpc ipt_REJECT ipt_state ip_conntrack
iptable_filter ip_tables dm_mod video button battery ac 3c59x floppy
ext3 jbd
CPU:    0
EIP:    0060:[<c013fc66>]    Not tainted VLI
EFLAGS: 00010002   (2.6.10-1.1074_FC4smp) 
EIP is at check_slabuse+0x3c/0xca
eax: ded60ea4   ebx: dc3d4e60   ecx: 00000001   edx: ded60000
esi: ded60000   edi: 00000000   ebp: df2efb48   esp: dff9bf2c
ds: 007b   es: 007b   ss: 0068
Process events/0 (pid: 6, threadinfo=dff9b000 task=dfedfac0)
Stack: 00000001 00000001 df2efb48 dc3d4e60 dc3d4db8 dc3d4f54 c013fd48
c140bc00 
       dc3d4e60 c014012b 00000008 00000000 c140bc00 c140bc04 00000283
dffc4000 
       c012ae6b 00000000 c0140085 ffffffff ffffffff 00000001 00000000
c011a367 
Call Trace:
 [<c013fd48>] check_redzone+0x54/0xff
 [<c014012b>] cache_reap+0xa6/0x1cb
 [<c012ae6b>] worker_thread+0x168/0x1d5
 [<c0140085>] cache_reap+0x0/0x1cb
 [<c011a367>] default_wake_function+0x0/0xc
 [<c011a367>] default_wake_function+0x0/0xc
 [<c012ad03>] worker_thread+0x0/0x1d5
 [<c012e081>] kthread+0x73/0x9b
 [<c012e00e>] kthread+0x0/0x9b
 [<c0102285>] kernel_thread_helper+0x5/0xb
Code: 0f 84 ac 00 00 00 31 ff 3b bb b8 00 00 00 0f 83 9e 00 00 00 8b
b3 b0 00 00 00 89 d8 0f af f7 03 75 0c 89 f2 e8 b6 dd ff ff 89 f2 <8b>
00 89 44 24 04 89 d8 e8 c6 dd ff ff 31 d2 8b 00 81 7c 24 04

At the moment this happened a machine was not doing outwardly
anything special, although some cron stuff could be runing, and
it was sitting idle at a shell prompt.  After that it went possum.
I could not get any response to a keyboard.  On a network it
was responding to pings but no login was possible.

This actually is repeatable.  While I was typing that report
using another machine the same incident happened again.
SysRq is usable yet and I attach what I managed to collect with
it.  The first thing which showed up when trying to use SysRq
was:

<7>atkbd.c: Keyboard on isa0060/serio0 reports too many keys pressed

????

Kernels 1069 refused to boot on a test machine with symptoms
like described in but #144480 so I did not try to investigate.
I did not see anything similar to the above with any other earlier
kernels.

Version-Release number of selected component (if applicable):
kernel 2.6.10-1.1074_FC4smp

How reproducible:
Looks pretty consistent but one has to wait for some time.
It bombed again.