Same bug on Ubuntu Server 10.10 x86.
$ lspci | grep Atheros
"Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01)"

Tried compat-wireless-2.6.36-5-spn, linux-backports-modules-compat-wireless-2.6.36-2.6.35-23-generic-pae and linux-backports-modules-wireless-2.6.35-23-generic-pae. 

kern.log follows
Jan  2 12:03:25 shyiko-us kernel: [74028.394727] wlan0: No active IBSS STAs - trying to scan for other IBSS networks with same SSID (merge)
Jan  2 12:03:30 shyiko-us kernel: [74032.444607] BUG: unable to handle kernel NULL pointer dereference at 00000080
Jan  2 12:03:30 shyiko-us kernel: [74032.444656] IP: [<c0216eac>] __kmalloc_track_caller+0x6c/0x170
Jan  2 12:03:30 shyiko-us kernel: [74032.444691] *pdpt = 000000002eba2001 *pde = 0000000000000000 
Jan  2 12:03:30 shyiko-us kernel: [74032.444716] Oops: 0000 [#1] SMP 
Jan  2 12:03:30 shyiko-us kernel: [74032.444735] last sysfs file: /sys/devices/pci0000:00/0000:00:16.0/0000:04:00.0/irq
Jan  2 12:03:30 shyiko-us kernel: [74032.444759] Modules linked in: ppp_async crc_ccitt xt_multiport ipt_MASQUERADE snd_hda_codec_nvhdmi snd_hda_codec_realtek ipt_REDIRECT iptable_nat nf_nat nf_conntrack_ipv4 ipt_REJECT nf_conntrack xt_tcpudp iptable_filter nf_defrag_ipv4 ip_tables x_tables arc4 ath9k snd_hda_intel nouveau mac80211 snd_hda_codec ttm snd_hwdep drm_kms_helper snd_pcm eeepc_wmi ath9k_common ath9k_hw sparse_keymap drm ath snd_timer cfg80211 agpgart i2c_algo_bit snd asus_atk0110 psmouse xhci_hcd led_class serio_raw shpchp soundcore snd_page_alloc i2c_nforce2 lp parport usb_storage ahci libahci r8169 mii
Jan  2 12:03:30 shyiko-us kernel: [74032.445072] 
Jan  2 12:03:30 shyiko-us kernel: [74032.445085] Pid: 719, comm: phy0 Not tainted 2.6.35-23-generic-pae #41-Ubuntu EB1012/EB1012
Jan  2 12:03:30 shyiko-us kernel: [74032.445109] EIP: 0060:[<c0216eac>] EFLAGS: 00010002 CPU: 2
Jan  2 12:03:30 shyiko-us kernel: [74032.445128] EIP is at __kmalloc_track_caller+0x6c/0x170
Jan  2 12:03:30 shyiko-us kernel: [74032.445145] EAX: c23067ec EBX: c0802888 ECX: c0802888 EDX: 00000000
Jan  2 12:03:30 shyiko-us kernel: [74032.445164] ESI: 000000d0 EDI: 00000080 EBP: ef633ea4 ESP: ef633e7c
Jan  2 12:03:30 shyiko-us kernel: [74032.445183]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Jan  2 12:03:30 shyiko-us kernel: [74032.445201] Process phy0 (pid: 719, ti=ef632000 task=ef561960 task.ti=ef632000)
Jan  2 12:03:30 shyiko-us kernel: [74032.445220] Stack:
Jan  2 12:03:30 shyiko-us kernel: [74032.445229]  00000000 00000000 c0512a8e c0513a28 00000246 000000d0 000001c4 ef5156c0
Jan  2 12:03:30 shyiko-us kernel: [74032.445275] <0> 000000d0 000000ff ef633ec4 c0512ab8 c08024d0 00000000 000000c0 ef594d80
Jan  2 12:03:30 shyiko-us kernel: [74032.445326] <0> ee940086 f032e000 ef633ee0 c0513a28 ffffffff f032e000 f766c480 ee940086
Jan  2 12:03:30 shyiko-us kernel: [74032.445381] Call Trace:
Jan  2 12:03:30 shyiko-us kernel: [74032.445400]  [<c0512a8e>] ? __alloc_skb+0x2e/0x100
Jan  2 12:03:30 shyiko-us kernel: [74032.445420]  [<c0513a28>] ? skb_copy+0x38/0x90
Jan  2 12:03:30 shyiko-us kernel: [74032.445439]  [<c0512ab8>] ? __alloc_skb+0x58/0x100
Jan  2 12:03:30 shyiko-us kernel: [74032.445458]  [<c0513a28>] ? skb_copy+0x38/0x90
Jan  2 12:03:30 shyiko-us kernel: [74032.445496]  [<f89a62f5>] ? ieee80211_ibss_rx_queued_mgmt+0x1d5/0x230 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.445523]  [<c0133618>] ? default_spin_lock_flags+0x8/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.445547]  [<c05f050f>] ? _raw_spin_lock_irqsave+0x2f/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.445584]  [<f89acd71>] ? ieee80211_iface_work+0x231/0x310 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.445610]  [<c0169dde>] ? run_workqueue+0x8e/0x150
Jan  2 12:03:30 shyiko-us kernel: [74032.445647]  [<f89acb40>] ? ieee80211_iface_work+0x0/0x310 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.445671]  [<c0169f24>] ? worker_thread+0x84/0xe0
Jan  2 12:03:30 shyiko-us kernel: [74032.445691]  [<c016e1a0>] ? autoremove_wake_function+0x0/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.445712]  [<c0169ea0>] ? worker_thread+0x0/0xe0
Jan  2 12:03:30 shyiko-us kernel: [74032.445731]  [<c016dd74>] ? kthread+0x74/0x80
Jan  2 12:03:30 shyiko-us kernel: [74032.445748]  [<c016dd00>] ? kthread+0x0/0x80
Jan  2 12:03:30 shyiko-us kernel: [74032.445767]  [<c010993e>] ? kernel_thread_helper+0x6/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.445783] Code: ec 75 5c 9c 58 8d 74 26 00 89 45 e8 fa 90 8d 74 26 00 64 8b 15 54 3d 90 c0 8b 03 8d 04 02 8b 38 85 ff 0f 84 99 00 00 00 8b 53 10 <8b> 14 17 89 10 8b 45 e8 50 9d 8d 74 26 00 85 ff 75 2a 8b 0d 24 
Jan  2 12:03:30 shyiko-us kernel: [74032.446664] EIP: [<c0216eac>] __kmalloc_track_caller+0x6c/0x170 SS:ESP 0068:ef633e7c
Jan  2 12:03:30 shyiko-us kernel: [74032.447308] CR2: 0000000000000080
Jan  2 12:03:30 shyiko-us kernel: [74032.447988] BUG: unable to handle kernel NULL pointer dereference at 00000080
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] IP: [<c021672a>] kmem_cache_alloc_notrace+0x4a/0xb0
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] *pdpt = 000000002eba2001 *pde = 0000000000000000 
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Oops: 0000 [#2] SMP 
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] last sysfs file: /sys/devices/pci0000:00/0000:00:16.0/0000:04:00.0/irq
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Modules linked in: ppp_async crc_ccitt xt_multiport ipt_MASQUERADE snd_hda_codec_nvhdmi snd_hda_codec_realtek ipt_REDIRECT iptable_nat nf_nat nf_conntrack_ipv4 ipt_REJECT nf_conntrack xt_tcpudp iptable_filter nf_defrag_ipv4 ip_tables x_tables arc4 ath9k snd_hda_intel nouveau mac80211 snd_hda_codec ttm snd_hwdep drm_kms_helper snd_pcm eeepc_wmi ath9k_common ath9k_hw sparse_keymap drm ath snd_timer cfg80211 agpgart i2c_algo_bit snd asus_atk0110 psmouse xhci_hcd led_class serio_raw shpchp soundcore snd_page_alloc i2c_nforce2 lp parport usb_storage ahci libahci r8169 mii
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] 
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Pid: 719, comm: phy0 Not tainted 2.6.35-23-generic-pae #41-Ubuntu EB1012/EB1012
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] EIP: 0060:[<c021672a>] EFLAGS: 00010002 CPU: 2
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] EIP is at kmem_cache_alloc_notrace+0x4a/0xb0
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] EAX: c23067ec EBX: 00008020 ECX: c03b0e3e EDX: 00000000
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] ESI: 00000080 EDI: c0802888 EBP: ef633a80 ESP: ef633a64
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Process phy0 (pid: 719, ti=ef632000 task=ef561960 task.ti=ef632000)
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Stack:
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  00008020 ef633a9c c0216c09 00000046 f0379b20 00000010 00000000 ef633ab4
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] <0> c03b0e3e 00008020 00000030 f0379b02 00000000 c6000000 ef633aac 00000000
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] <0> 00008020 f0379b20 00000010 00000000 ef633adc c03c1089 00000000 f0379b30
Jan  2 12:03:30 shyiko-us kernel: [74032.448491] Call Trace:
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c0216c09>] ? kmem_cache_alloc+0xa9/0x110
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03b0e3e>] ? acpi_ds_create_walk_state+0x43/0xd1
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03c1089>] ? acpi_ps_execute_method+0xf0/0x25b
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03bc6f9>] ? acpi_ns_evaluate+0xd1/0x192
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03c57c0>] ? acpi_ut_copy_eobject_to_iobject+0x89/0x95
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03bc0f1>] ? acpi_os_allocate_zeroed+0x2d/0x2f
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c03bc1c9>] ? acpi_evaluate_object+0xd6/0x1c5
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c0506f38>] ? wmi_evaluate_method+0xe8/0x100
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<f892007b>] ? update_bl_status+0x4b/0x60 [eeepc_wmi]
Jan  2 12:03:30 shyiko-us kernel: [74032.448491]  [<c039e7a9>] ? fb_notifier_callback+0x89/0xb0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f4163>] ? notifier_call_chain+0x43/0x60
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c017383b>] ? __blocking_notifier_call_chain+0x4b/0x70
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c017387f>] ? blocking_notifier_call_chain+0x1f/0x30
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c038dca6>] ? fb_notifier_call_chain+0x16/0x20
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c038e652>] ? fb_blank+0x52/0x60
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c039aebd>] ? fbcon_blank+0x1cd/0x260
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c03ff388>] ? vt_console_print+0x218/0x2d0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c03ff170>] ? vt_console_print+0x0/0x2d0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0133618>] ? default_spin_lock_flags+0x8/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f050f>] ? _raw_spin_lock_irqsave+0x2f/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0153087>] ? release_console_sem+0x1a7/0x1f0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0133618>] ? default_spin_lock_flags+0x8/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f050f>] ? _raw_spin_lock_irqsave+0x2f/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0160c5c>] ? lock_timer_base+0x2c/0x60
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0161b3d>] ? mod_timer+0x12d/0x280
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c040034f>] ? do_unblank_screen+0x9f/0x160
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c040041f>] ? unblank_screen+0xf/0x20
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0365ab5>] ? bust_spinlocks+0x15/0x40
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f1cc4>] ? oops_end+0x34/0xd0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0134694>] ? no_context+0xc4/0xe0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0134740>] ? __bad_area_nosemaphore+0x90/0x130
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<f8734ebc>] ? regulatory_hint_found_beacon+0x10c/0x120 [cfg80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c01347f7>] ? bad_area_nosemaphore+0x17/0x20
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f4058>] ? do_page_fault+0x378/0x440
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<f89a23a2>] ? ieee80211_bss_info_update+0xd2/0x1d0 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c035ab6f>] ? cpumask_next_and+0x1f/0x40
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c014376b>] ? find_busiest_group+0x1db/0x7c0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f3ce0>] ? do_page_fault+0x0/0x440
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f1117>] ? error_code+0x73/0x78
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0216eac>] ? __kmalloc_track_caller+0x6c/0x170
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0512a8e>] ? __alloc_skb+0x2e/0x100
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0513a28>] ? skb_copy+0x38/0x90
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0512ab8>] ? __alloc_skb+0x58/0x100
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0513a28>] ? skb_copy+0x38/0x90
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<f89a62f5>] ? ieee80211_ibss_rx_queued_mgmt+0x1d5/0x230 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0133618>] ? default_spin_lock_flags+0x8/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c05f050f>] ? _raw_spin_lock_irqsave+0x2f/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<f89acd71>] ? ieee80211_iface_work+0x231/0x310 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0169dde>] ? run_workqueue+0x8e/0x150
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<f89acb40>] ? ieee80211_iface_work+0x0/0x310 [mac80211]
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0169f24>] ? worker_thread+0x84/0xe0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c016e1a0>] ? autoremove_wake_function+0x0/0x50
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c0169ea0>] ? worker_thread+0x0/0xe0
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c016dd74>] ? kthread+0x74/0x80
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c016dd00>] ? kthread+0x0/0x80
Jan  2 12:03:30 shyiko-us kernel: [74032.469249]  [<c010993e>] ? kernel_thread_helper+0x6/0x10
Jan  2 12:03:30 shyiko-us kernel: [74032.469249] Code: 85 c0 f6 c3 10 75 4a 9c 58 8d 74 26 00 89 45 f0 fa 90 8d 74 26 00 64 8b 15 54 3d 90 c0 8b 07 8d 04 02 8b 30 85 f6 74 4c 8b 57 10 <8b> 14 16 89 10 8b 45 f0 50 9d 8d 74 26 00 85 f6 75 24 89 f0 8b 
Jan  2 12:03:30 shyiko-us kernel: [74032.469249] EIP: [<c021672a>] kmem_cache_alloc_notrace+0x4a/0xb0 SS:ESP 0068:ef633a64
Jan  2 12:03:30 shyiko-us kernel: [74032.469249] CR2: 0000000000000080
Jan  2 12:03:30 shyiko-us kernel: [74032.469249] ---[ end trace 71d3e82cbc3c1055 ]---