"BUG: unable to handle kernel NULL pointer dereference at 00000018" when trying to configure one display centered above another

[Bryce Harrington]

I was working on diagnosing bug 868354 (Duplicate indicators bar and desktops with overlapped screens) by running the gnome-display-properties applet on a laptop with external monitor. I was enabling/disabling the displays and moving them around to different orientations.

At one point I (roughly) centered the smaller laptop display above the external monitor, hit apply, and the system locked up. dmesg shows:

[ 1367.073390] BUG: unable to handle kernel NULL pointer dereference at 00000018
[ 1367.073467] IP: [<f8a090f3>] i915_gem_get_aperture_ioctl+0x63/0xb0 [i915]
[ 1367.073530] *pdpt = 0000000033f6b001 *pde = 0000000000000000
[ 1367.073571] Oops: 0000 [#1] SMP
[ 1367.073602] Modules linked in: joydev parport_pc ppdev rfcomm snd_usb_audio usbhid snd_usbmidi_lib hid tpm_infineon bnep arc4 btusb bluetooth snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi input_polldev pcmcia snd_seq_midi_event uvcvideo iwlwifi videodev snd_seq yenta_socket pcmcia_rsrc mac80211 psmouse pcmcia_core serio_raw snd_timer snd_seq_device cfg80211 snd nfsd tpm_tis nfs soundcore snd_page_alloc lockd fscache auth_rpcgss nfs_acl sunrpc binfmt_misc fujitsu_laptop i915 drm_kms_helper drm i2c_algo_bit video lp parport sdhci_pci sdhci firewire_ohci firewire_core crc_itu_t tg3
[ 1367.074156]
[ 1367.074172] Pid: 1208, comm: Xorg Not tainted 3.2.0-5-generic-pae #11-Ubuntu FUJITSU LifeBook T4410/FJNB206
[ 1367.074246] EIP: 0060:[<f8a090f3>] EFLAGS: 00013202 CPU: 1
[ 1367.074295] EIP is at i915_gem_get_aperture_ioctl+0x63/0xb0 [i915]
[ 1367.074338] EAX: f74df24c EBX: f74de000 ECX: f74df1dc EDX: 00000000
[ 1367.074377] ESI: f4794c14 EDI: 05d09000 EBP: f3361e8c ESP: f3361e74
[ 1367.074417] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1367.074451] Process Xorg (pid: 1208, ti=f3360000 task=f301b2c0 task.ti=f3360000)
[ 1367.074501] Stack:
[ 1367.074517] 00000000 00000000 f3361edc f6d61c80 f4794c00 80106463 f3361f6c f8944f28
[ 1367.074596] 00000001 f895e5ed f8959bb6 f895fc98 000004b8 80106463 00000063 0000e200
[ 1367.074684] 00000001 00000000 00000063 bfc22340 f8a09090 00000010 f8a4c450 ffffffea
[ 1367.074766] Call Trace:
[ 1367.076006] [<f8944f28>] drm_ioctl+0x378/0x480 [drm]
[ 1367.076006] [<f8a09090>] ? i915_gem_init_ioctl+0x80/0x80 [i915]
[ 1367.076006] [<c117bbc8>] ? fsnotify+0x198/0x250
[ 1367.076006] [<f8944bb0>] ? drm_copy_field+0x80/0x80 [drm]
[ 1367.076006] [<c1154a89>] do_vfs_ioctl+0x79/0x2d0
[ 1367.076006] [<c1144180>] ? wait_on_retry_sync_kiocb+0x50/0x50
[ 1367.076006] [<c1154d4f>] sys_ioctl+0x6f/0x80
[ 1367.076006] [<c15ac59f>] sysenter_do_call+0x12/0x28
[ 1367.076006] Code: 93 4c 12 00 00 8d 83 4c 12 00 00 c7 45 e8 00 00 00 00 c7 45 ec 00 00 00 00 39 d0 8d 4a 98 74 22 31 ff 8d b6 00 00 00 00 8b 51 54
[ 1367.076006] 7a 18 8b 51 68 39 d0 8d 4a 98 75 f0 89 7d e8 c7 45 ec 00 00
[ 1367.076006] EIP: [<f8a090f3>] i915_gem_get_aperture_ioctl+0x63/0xb0 [i915] SS:ESP 0068:f3361e74
[ 1367.076006] CR2: 0000000000000018

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: xorg 1:7.6+7ubuntu7
ProcVersionSignature: Ubuntu 3.2.0-5.11-generic-pae 3.2.0-rc5
Uname: Linux 3.2.0-5-generic-pae i686
ApportVersion: 1.90-0ubuntu1
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,imgpng,gnomecompat,regex,place,snap,vpswitch,mousepoll,grid,compiztoolbox,animation,move,session,resize,unitymtgrabhandles,workarounds,wall,expo,fade,ezoom,scale,unityshell]
Date: Fri Dec 16 17:31:10 2011
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, whatever it takes to get this fixed in Ubuntu
GraphicsCard:
 Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Fujitsu Limited. Device [10cf:1458]
   Subsystem: Fujitsu Limited. Device [10cf:1458]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha i386 (20111121)
MachineType: FUJITSU LifeBook T4410
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-5-generic-pae root=UUID=74b73169-6ac4-4698-bb5e-1f9b21250507 ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 09/30/2009
dmi.bios.vendor: FUJITSU // Phoenix Technologies Ltd.
dmi.bios.version: Version 1.05
dmi.board.name: FJNB206
dmi.board.vendor: FUJITSU
dmi.chassis.type: 10
dmi.chassis.vendor: A40R8CE708EA1001
dmi.modalias: dmi:bvnFUJITSU//PhoenixTechnologiesLtd.:bvrVersion1.05:bd09/30/2009:svnFUJITSU:pnLifeBookT4410:pvr:rvnFUJITSU:rnFJNB206:rvr:cvnA40R8CE708EA1001:ct10:cvr:
dmi.product.name: LifeBook T4410
dmi.sys.vendor: FUJITSU
version.compiz: compiz 1:0.9.6+bzr20110929-0ubuntu8
version.libdrm2: libdrm2 2.4.27-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.10.4-1ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1

[brncsk (adam-barancsuk)]

It also happened to me a couple of times in the last few weeks. I also had random hangs (without the above kernel panic message shown) that could only be solved by hard resetting the machine. I'm on precise and running the latest unity from the unity-team/staging PPA.

[Brad Figg (brad-figg)]

Thank you for taking the time to file a bug report on this issue.

However, given the number of bugs that the Kernel Team receives during any development cycle it is impossible for us to review them all. Therefore, we occasionally resort to using automated bots to request further testing. This is such a request.

We have noted that there is a newer version of the development kernel than the one you last tested when this issue was found. Please test again with the newer kernel and indicate in the bug if this issue still exists or not.

You can update to the latest development kernel by simply running the following commands in a terminal window:

    sudo apt-get update
    sudo apt-get upgrade

If the bug still exists, change the bug status from Incomplete to Confirmed. If the bug no longer exists, change the bug status from Incomplete to Fix Released.

If you want this bot to quit automatically requesting kernel tests, add a tag named: bot-stop-nagging.

 Thank you for your help, we really do appreciate it.

[Bryce Harrington (bryce)]

After updating to 3.2.0-6.12, I seem to be unable to reproduce the bug.