BUG: unable to handle kernel NULL pointer dereference at 00000069
IP: [<c0409958>] usb_ifnum_to_if+0x18/0x50
*pde = cf547067 
Oops: 0000 [#1] SMP 
last sysfs file: /sys/devices/pci0000:00/0000:00:1c.0/0000:04:00.0/sound/card0/uevent
Modules linked in: binfmt_misc ppdev snd_hda_codec_realtek bridge stp snd_hda_intel bnep snd_ctxfi snd_hda_codec snd_pcm_oss snd_mixer_oss snd_usb_audio snd_usb_lib snd_hwdep lp snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi gspca_sn9c20x snd_rawmidi gspca_main asus_atk0110 psmouse videodev serio_raw v4l1_compat snd_seq_midi_event parport nvidia(P) btusb snd_seq snd_timer snd_seq_device iptable_filter ip_tables x_tables snd soundcore snd_page_alloc dm_raid45 xor usbhid usb_storage atl1e floppy ohci1394 ieee1394 intel_agp agpgart

Pid: 2229, comm: pulseaudio Tainted: P           (2.6.31-14-generic #48-Ubuntu) System Product Name
EIP: 0060:[<c0409958>] EFLAGS: 00010206 CPU: 2
EIP is at usb_ifnum_to_if+0x18/0x50
EAX: f699c000 EBX: f699c000 ECX: 00000000 EDX: 00000002
ESI: 00000065 EDI: f6b6e088 EBP: f6ac5e88 ESP: f6ac5e7c
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process pulseaudio (pid: 2229, ti=f6ac4000 task=f5f2f110 task.ti=f6ac4000)
Stack:
 f699c000 00000002 f6b6e088 f6ac5ec0 c041264a 00000010 f6ac5eb8 c01d392e
<0> f5f8a9bc f6ac5eb8 f9c7e1c4 00000000 f57a2800 f5f4ed18 f6971400 f5f4ed18
<0> f6b6e088 f6ac5ecc f9ce743e f66de300 f6ac5ed8 f9c6f206 f5f4ec00 f6ac5ef8
Call Trace:
 [<c041264a>] ? usb_set_interface+0x3a/0x1d0
 [<c01d392e>] ? __vunmap+0x6e/0xd0
 [<f9ce743e>] ? snd_usb_capture_close+0x1e/0x40 [snd_usb_audio]
 [<f9c6f206>] ? snd_pcm_release_substream+0x46/0x70 [snd_pcm]
 [<f9c6f263>] ? snd_pcm_release+0x33/0x90 [snd_pcm]
 [<f80bd47e>] ? snd_disconnect_release+0x8e/0xd0 [snd]
 [<c01e8cba>] ? __fput+0xda/0x1f0
 [<c01e8de5>] ? fput+0x15/0x20
 [<c01ce3ed>] ? remove_vma+0x2d/0x60
 [<c01cfb7a>] ? do_munmap+0x21a/0x280
 [<c01cfc1d>] ? sys_munmap+0x3d/0x60
 [<c010336c>] ? syscall_call+0x7/0xb
Code: 74 0c 8b 02 e8 5a 5c f9 ff a1 a4 28 8a c0 5d c3 90 90 90 55 89 e5 57 56 53 8b b0 30 01 00 00 85 f6 75 08 31 c0 5b 5e 5f 5d c3 90 <0f> b6 7e 04 85 ff 74 f0 8b 46 50 8b 08 0f b6 59 02 31 c9 39 d3 
EIP: [<c0409958>] usb_ifnum_to_if+0x18/0x50 SS:ESP 0068:f6ac5e7c
CR2: 0000000000000069
---[ end trace 18d9b2fc6293e38d ]---