BUG: unable to handle kernel NULL pointer dereference at 00000004

That Ooops stack says something so bad occured that neither the EIP nor SP for the process were valid. This leaves us with almost no information. Is this reproducible at all on the latest Karmic kernel? If not we really are not likely to be able to figure out what the trigger was from what was collected. From what we have we cannot fix this, so I'll mark it Won't Fix, but if you are able to reproduce it please do reopen this bug.

TBH, I'm currently unable to use karmic at all because it just freezes all the time. This crash occurs within the first couple of minutes of starting up. The crash is almost random, sometimes it'll happen when i'm still in GDM or most of the time it'll occur when i'm in gnome.

A couple of interesting things are the crash has two symptoms, sometimes it'll freeze everything (cant do anything but restart). Or sometimes the crash will restart X server and then once its restarted it will freeze proper 10-20 seconds later. Another interesting thing is that karmic never crashes if i boot up through recovery mode (via Grub), then go to Root console and run startx through there (affectively running Ubuntu as root).

Apport has only picked up this crash once, which is how i submitted this bug (this raises the question if this crash is even related to this bug, let me know if should create a new bug). Also now again when crash restarts x server, i have just enough time to do a vt switch and dump the dmesg output in to a file. I have attached the dmesg log.

I just recieved this kernel error as well.

I have the same error as in the title, but absolutely no idea what triggers it. It happens once in about 10-15-20 days. The simptoms are high load (it rises to about 10), but no cpu or disk activity; gnom-terminal is freezes, but other things are reasonably useable.
I use the latest kernel in karmic:
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[gab0r@asus-lapi ~]$ uname -a
Linux asus-lapi 2.6.31-17-generic #54-Ubuntu SMP Thu Dec 10 16:20:31 UTC 2009 i686 GNU/Linux
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snippet from syslog:
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Jan 18 16:28:46 asus-lapi kernel: [492310.041650] device eth0 left promiscuous mode
Jan 18 16:29:03 asus-lapi kernel: [492326.551836] BUG: unable to handle kernel NULL pointer dereference at 00000004
Jan 18 16:29:03 asus-lapi kernel: [492326.551850] IP: [<c0127b28>] __ticket_spin_lock+0x8/0x20
Jan 18 16:29:03 asus-lapi kernel: [492326.551868] *pde = 5e48d067
Jan 18 16:29:03 asus-lapi kernel: [492326.551875] Oops: 0002 [#1] SMP
Jan 18 16:29:03 asus-lapi kernel: [492326.551883] last sysfs file: /sys/devices/pci0000:00/0000:00:1f.1/host0/target0:0:0/0:0:0:0/block/sda/sda1/stat
Jan 18 16:29:03 asus-lapi kernel: [492326.551892] Modules linked in: mmc_block nls_iso8859_1 nls_cp437 vfat fat ipaq usbserial usb_storage binfmt_misc vboxnetadp vboxnetflt vboxdrv smsc_ircc2 joydev snd_hda_codec_realtek bridge stp bnep btusb snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy iptable_filter snd_seq_oss pcmcia ip_tables x_tables snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device ppdev psmouse serio_raw libipw lib80211 sdhci_pci sdhci yenta_socket rsrc_nonstatic pcmcia_core snd irda crc_ccitt soundcore snd_page_alloc parport_pc lp parport asus_laptop led_class dm_raid45 xor usbhid skge ohci1394 ieee1394 radeon ttm drm i2c_algo_bit video output intel_agp agpgart [last unloaded: ipw2200]
Jan 18 16:29:03 asus-lapi kernel: [492326.552011]
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] Pid: 6, comm: events/0 Tainted: G M (2.6.31-17-generic #54-Ubuntu) M6VA
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] EIP: 0060:[<c0127b28>] EFLAGS: 00010202 CPU: 0
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] EIP is at __ticket_spin_lock+0x8/0x20
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] EAX: 00000004 EBX: f7065f48 ECX: c1cbeba4 EDX: 00000100
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] ESI: f07544bc EDI: c1cbeba0 EBP: f7065f1c ESP: f7065f1c
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] Process events/0 (pid: 6, ti=f7064000 task=f704bed0 task.ti=f7064000)
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] Stack:
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] f7065f24 c0570dc8 f7065f2c faf305de f7065f58 faeda21d 00000000 f7065f48
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] <0> f7065f8c c056ee8c f0754410 00000000 f07544bc c1cbeba0 c1cbeba0 f7065f8c
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] <0> c01579ce c08145c0 f704c168 c08145c0 a4a2cba8 0001bfc4 c08145c0 c1cbeba4
Jan 18 16:29:03 asus-lapi kernel: [492326.552011] Call Trace:
Jan 18 16:29:03 asus-lapi kernel: [492326.552011...

Hi Harshid,

This bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? Can you try with the latest development release of Ubuntu? ISO CD images are available from http://cdimage.ubuntu.com/releases/ .

If it remains an issue, could you run the following command from a Terminal (Applications->Accessories->Terminal). It will automatically gather and attach updated debug information to this report.

apport-collect -p linux 426870

Also, if you could test the latest upstream kernel available that would be great. It will allow additional upstream developers to examine the issue. Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag. This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text. Please let us know your results.

Thanks in advance.

    [This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

Hi Jeremy,

To be honest, I don't know if this bug is still present in Ubuntu. I switched my graphics card from Ati to Nvidia and consequently am now using the Nvidia driver(Nouveau). This solved the problem for me, which means this bug was being triggered by the mesa Ati driver, and not by ACPI code in the kernel.

To my understanding the Ati mesa driver is known for being very good at crashing so I don't know why I expected anything better. *sigh* You can close this bug.