# I just had a kernel panic

## Aquous

Hi guys

As I was watching a movie I noticed my USB stick's light was flashing. Dmesg reported that the USB had disconnected. Curious, I removed and reinserted the USB stick. I was then greeted by this message:

```
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008

IP: [<ffffffff81218c9b>] __elv_add_request+0x16b/0x210

PGD 1052d7067 PUD 1116e6067 PMD 0 

Oops: 0002 [#1] PREEMPT SMP 

last sysfs file: /sys/devices/pci0000:00/0000:00:1a.2/usb5/5-2/5-2:1.0/input/input3/name

CPU 2 

Modules linked in: vboxnetadp vboxnetflt vboxdrv vhba

Pid: 16000, comm: umount Not tainted 2.6.39-gentoo-r1 #4 Gigabyte Technology Co., Ltd. H55M-USB3/H55M-USB3

RIP: 0010:[<ffffffff81218c9b>]  [<ffffffff81218c9b>] __elv_add_request+0x16b/0x210

RSP: 0018:ffff88011f9a7bd8  EFLAGS: 00010006

RAX: 0000000000000000 RBX: ffff88011cc5d248 RCX: 0000000000000001

RDX: 0000000000000001 RSI: ffff88011cc5d248 RDI: ffff880121f03280

RBP: ffff880121f03280 R08: ffffffff8121fdf0 R09: ffff880121f03280

R10: ffff88011f9a7dd8 R11: ffff880120cf6800 R12: 0000000000000001

R13: ffff88011f9a7dd8 R14: ffff88008b2f0900 R15: 0000000000000000

FS:  00007ff38c8ab740(0000) GS:ffff880127c80000(0000) knlGS:0000000000000000

CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000000000000008 CR3: 000000011d1f9000 CR4: 00000000000006e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400

Process umount (pid: 16000, threadinfo ffff88011f9a6000, task ffff880104324c60)

Stack:

 0000000000001000 ffff880121f03280 ffff88011cc5d248 ffffffff8121fe74

 ffff88011cc5d248 ffff88011f9a7c78 ffff88011cc5d248 ffffffff8121ff21

 ffff88011f9a7dd8 ffff88008b2f0900 0000000000000000 ffffffff8121b4e3

Call Trace:

 [<ffffffff8121fe74>] ? blk_execute_rq_nowait+0x54/0xa0

 [<ffffffff8121ff21>] ? blk_execute_rq+0x61/0xb0

 [<ffffffff8121b4e3>] ? get_request_wait+0x23/0x140

 [<ffffffff813fac1d>] ? scsi_execute+0xfd/0x170

 [<ffffffff813fad51>] ? scsi_execute_req+0xc1/0x160

 [<ffffffff813f5fd9>] ? ioctl_internal_command.clone.4+0x49/0x130

 [<ffffffff813f6122>] ? scsi_set_medium_removal+0x62/0xa0

 [<ffffffff81065bd4>] ? bit_waitqueue+0x14/0xc0

 [<ffffffff8143ff65>] ? cdrom_release+0x135/0x250

 [<ffffffff8140706e>] ? sr_block_release+0x2e/0x60

 [<ffffffff811165ec>] ? __blkdev_put+0x17c/0x1c0

 [<ffffffff810e7623>] ? deactivate_locked_super+0x43/0x70

 [<ffffffff8110300a>] ? sys_umount+0x7a/0x3c0

 [<ffffffff8159b0fb>] ? system_call_fastpath+0x16/0x1b

Code: 5b 5d ff e0 0f 1f 40 00 83 fa 03 0f 84 0f ff ff ff e9 d7 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 81 4b 40 00 08 00 00 48 8b 45 00 

 89 58 08 48 89 03 48 89 6b 08 48 89 5d 00 48 83 c4 08 5b 5d 

RIP  [<ffffffff81218c9b>] __elv_add_request+0x16b/0x210

 RSP <ffff88011f9a7bd8>

CR2: 0000000000000008

---[ end trace 3123247b545151a2 ]---
```

Now, the reason for my posting this is that I can't reproduce the problem - it appears to have been a random fluke. So should I still report a bug?

Note: immediately below this message another one had started to appear on screen, but the system had locked up before that message had finished printing. Also, that second oops did not make it into the syslog.

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## bjlockie

I wouldn't report it since it is not reproducible.

 *Quote:*   

> Modules linked in: vboxnetadp vboxnetflt vboxdrv vhba

 

Make sure VirtualBox is the latest version.

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## Aquous

OK, thanks for the input   :Smile: 

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## table

 *Aquous wrote:*   

> OK, thanks for the input  

 

hi,

I currently have same problem starting my winxp VM with virtualbox.

I think cause is some kernel modules because recently i've removed some modules from linux kernel and before all works correctly.

```

Oops: 0002 [#1] PREEMPT SMP
```

this is the error and after that i can only poweroff my laptop with power button   :Crying or Very sad: 

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