BUG: unable to handle kernel NULL pointer dereference at 000000bd
IP: [<c0492e77>] kfree_skb+0x17/0x80
*pde = b9237067 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/device:0e/PNP0C0A:00/power_supply/BAT0/charge_full
Modules linked in: isofs udf crc_itu_t cbc aes_i586 aes_generic binfmt_misc ppdev snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss arc4 snd_seq_midi snd_rawmidi snd_seq_midi_event ecb snd_seq ath9k snd_timer joydev iptable_filter snd_seq_device mac80211 ip_tables ath dm_crypt snd soundcore x_tables snd_page_alloc psmouse lp cfg80211 atl1c led_class serio_raw parport fbcon tileblit font bitblit softcursor i915 drm i2c_algo_bit intel_agp video output agpgart

Pid: 788, comm: phy0 Tainted: G        W  (2.6.31-14-generic #48-Ubuntu) Aspire 5732Z    
EIP: 0060:[<c0492e77>] EFLAGS: 00010202 CPU: 1
EIP is at kfree_skb+0x17/0x80
EAX: 00000001 EBX: 00000001 ECX: f50b6900 EDX: 00000000
ESI: 00000009 EDI: f50b6900 EBP: f5987c98 ESP: f5987c8c
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process phy0 (pid: 788, ti=f5986000 task=f596e480 task.ti=f5986000)
Stack:
 f50b6900 00000009 f50b6900 f5987ca4 c049305d f50b6900 f5987cb0 c0492d9b
<0> f707c1a0 f5987cb8 c0492e3c f5987cf4 f8f51eaf f59dd000 f50b6900 00000764
<0> 00000000 f707d148 f94fca00 f59dd000 f459b4b2 f50b6920 f50b6900 f50b6900
Call Trace:
 [<c049305d>] ? skb_release_head_state+0x5d/0xe0
 [<c0492d9b>] ? __kfree_skb+0xb/0x90
 [<c0492e3c>] ? consume_skb+0x1c/0x40
 [<f8f51eaf>] ? ieee80211_tx_status+0x43f/0x470 [mac80211]
 [<f94d8b24>] ? ath_tx_complete+0x124/0x150 [ath9k]
 [<f94d8bc1>] ? ath_tx_complete_buf+0x71/0xc0 [ath9k]
 [<f94d9ad0>] ? ath_tx_complete_aggr+0x3f0/0x780 [ath9k]
 [<f94d9f2f>] ? ath_draintxq+0xcf/0x280 [ath9k]
 [<f94db1ee>] ? ath_drain_all_txq+0xce/0x140 [ath9k]
 [<f94d70e2>] ? ath_set_channel+0x82/0x200 [ath9k]
 [<f94d3aae>] ? ath_update_chainmask+0x7e/0x90 [ath9k]
 [<f94d7407>] ? ath9k_config+0x1a7/0x200 [ath9k]
 [<f8f51972>] ? ieee80211_hw_config+0x72/0xb0 [mac80211]
 [<f8f594ad>] ? ieee80211_set_disassoc+0x1ad/0x240 [mac80211]
 [<f8f5aa4e>] ? ieee80211_associated+0x1be/0x1e0 [mac80211]
 [<f8f5ca52>] ? ieee80211_sta_work+0x162/0x1c0 [mac80211]
 [<c0157a7e>] ? run_workqueue+0x6e/0x140
 [<f8f5c8f0>] ? ieee80211_sta_work+0x0/0x1c0 [mac80211]
 [<c0157bd8>] ? worker_thread+0x88/0xe0
 [<c015c280>] ? autoremove_wake_function+0x0/0x40
 [<c0157b50>] ? worker_thread+0x0/0xe0
 [<c015bf8c>] ? kthread+0x7c/0x90
 [<c015bf10>] ? kthread+0x0/0x90
 [<c0104007>] ? kernel_thread_helper+0x7/0x10
Code: 5d 8d 76 00 c3 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 e5 83 ec 0c 85 c0 89 1c 24 89 c3 89 74 24 04 89 7c 24 08 74 24 <8b> 80 bc 00 00 00 83 f8 01 75 28 0f ae e8 89 f6 8b 3d 44 88 78 
EIP: [<c0492e77>] kfree_skb+0x17/0x80 SS:ESP 0068:f5987c8c
CR2: 00000000000000bd
---[ end trace 0cbf8213014c26f3 ]---