BUG: unable to handle kernel NULL pointer dereference at 0000000000000088
IP: [<ffffffff81039739>] __ticket_spin_lock+0x9/0x20
PGD 5a143067 PUD 81dc1067 PMD 0 
Oops: 0002 [#1] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:1e.0/0000:04:03.0/local_cpus
CPU 0 
Modules linked in: binfmt_misc ppdev vboxnetadp vboxnetflt vboxdrv snd_hda_codec_atihdmi snd_hda_codec_realtek saa7134_alsa tuner_simple tuner_types fbcon tileblit tea5767 snd_hda_intel font bitblit softcursor snd_hda_codec vga16fb snd_hwdep tuner snd_pcm_oss snd_mixer_oss snd_pcm vgastate snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event saa7134 snd_seq snd_timer ir_common v4l2_common videodev v4l1_compat v4l2_compat_ioctl32 videobuf_dma_sg videobuf_core snd_seq_device snd tveeprom radeon soundcore ttm drm_kms_helper snd_page_alloc intel_agp drm i2c_algo_bit asus_atk0110 lp parport usbhid ohci1394 atl1 mii ieee1394
Pid: 15, comm: events/0 Tainted: G        W  2.6.32-15-generic #22-Ubuntu P5KC
RIP: 0010:[<ffffffff81039739>]  [<ffffffff81039739>] __ticket_spin_lock+0x9/0x20
RSP: 0018:ffff88012bb33d00  EFLAGS: 00010206
RAX: 0000000000000100 RBX: ffff8800bf3dc600 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000088
RBP: ffff88012bb33d00 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8800bf3dc660 R14: 0000000000000088 R15: ffffffffa01787a0
FS:  0000000000000000(0000) GS:ffff880028200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 0000000000000088 CR3: 00000000b04f1000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process events/0 (pid: 15, threadinfo ffff88012bb32000, task ffff88012bb2ade0)
Stack:
 ffff88012bb33d10 ffffffff8155eede ffff88012bb33d70 ffffffffa00e23da
<0> ffff8800bf3dc644 ffff8800bf3dc600 ffff8800bf3dc600 ffff8800bf3dd4b8
<0> ffff88012bb33d50 ffff8800bf3dc6b8 ffff8800bf3dc600 ffff8800bf3dc600
Call Trace:
 [<ffffffff8155eede>] _spin_lock+0xe/0x20
 [<ffffffffa00e23da>] ttm_bo_cleanup_refs+0xda/0x2a0 [ttm]
 [<ffffffffa00e2655>] ttm_bo_delayed_delete+0xb5/0x170 [ttm]
 [<ffffffffa00e2710>] ? ttm_bo_delayed_workqueue+0x0/0x40 [ttm]
 [<ffffffffa00e272f>] ttm_bo_delayed_workqueue+0x1f/0x40 [ttm]
 [<ffffffff8107e9b7>] run_workqueue+0xc7/0x1a0
 [<ffffffff8107eb33>] worker_thread+0xa3/0x110
 [<ffffffff81083580>] ? autoremove_wake_function+0x0/0x40
 [<ffffffff8107ea90>] ? worker_thread+0x0/0x110
 [<ffffffff81083206>] kthread+0x96/0xa0
 [<ffffffff8101422a>] child_rip+0xa/0x20
 [<ffffffff81083170>] ? kthread+0x0/0xa0
 [<ffffffff81014220>] ? child_rip+0x0/0x20
Code: 00 00 48 c7 c2 3e 95 03 81 48 c7 c1 41 95 03 81 e9 dd fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 55 b8 00 01 00 00 48 89 e5 <f0> 66 0f c1 07 38 e0 74 06 f3 90 8a 07 eb f6 c9 c3 66 0f 1f 44 
RIP  [<ffffffff81039739>] __ticket_spin_lock+0x9/0x20
 RSP <ffff88012bb33d00>
CR2: 0000000000000088
---[ end trace 94142127dabbae38 ]---