I was able to build the module with the attached patch. My kernel then oops when I modprobe snd_hda_intel. My system: root@emma:/usr/src# lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu intrepid (development branch) Release: 8.10 Codename: intrepid linux-image-2.6.27-6-generic 2.6.27-6.9 alsa-source 1.0.17.dfsg-2ubuntu1 [26991.869241] HDA Intel 0000:00:1b.0: power state changed by ACPI to D0 [26991.869258] HDA Intel 0000:00:1b.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 [26991.869290] HDA Intel 0000:00:1b.0: setting latency timer to 64 [26991.968263] BUG: unable to handle kernel NULL pointer dereference at 00000000 [26991.968269] IP: [] vsnprintf+0x3a/0x7b0 [26991.968278] *pde = 00000000 [26991.968287] Oops: 0000 [#1] SMP [26991.968293] Modules linked in: snd_hda_intel(+) snd_hwdep snd_pcm_oss snd_pcm snd_page_alloc snd_mixer_oss snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device snd soundcore btusb bluetooth ipv6 af_packet i915 drm binfmt_misc sbs sbshc pci_slot nf_conntrack_ftp nf_conntrack_irc ipt_ULOG xt_limit xt_tcpudp xt_state nf_conntrack_ipv4 nf_conntrack iptable_filter ip_tables x_tables visor usbserial vboxdrv sbp2 lp loop usbhid pcmcia hid joydev arc4 ecb crypto_blkcipher iwl3945 rfkill parport_pc evdev parport mac80211 yenta_socket led_class rsrc_nonstatic psmouse video output pcmcia_core serio_raw cfg80211 container tpm_infineon tpm tpm_bios battery pcspkr ac button intel_agp agpgart wmi iTCO_wdt iTCO_vendor_support shpchp pci_hotplug ext3 jbd mbcache sr_mod cdrom ata_generic sd_mod crc_t10dif sg ata_piix pata_acpi ahci ohci1394 tg3 libata ieee1394 scsi_mod dock libphy ehci_hcd uhci_hcd usbcore dm_mirror dm_log dm_snapshot dm_mod thermal processor fan fbcon tileblit font bitblit softcursor uvesafb fuse [last unloaded: soundcore] [26991.968392] [26991.968396] Pid: 11100, comm: modprobe Tainted: P (2.6.27-6-generic #1) [26991.968399] EIP: 0060:[] EFLAGS: 00010292 CPU: 1 [26991.968404] EIP is at vsnprintf+0x3a/0x7b0 [26991.968406] EAX: dd1accb0 EBX: 00000000 ECX: 00000000 EDX: 00000014 [26991.968409] ESI: fffffff4 EDI: f7bfee80 EBP: f741bd44 ESP: f741bc20 [26991.968411] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 [26991.968413] Process modprobe (pid: 11100, ti=f741a000 task=c1c13240 task.ti=f741a000) [26991.968415] Stack: 00000000 00000400 f741bc44 0012654d 00000000 c1901fe0 c1901fe0 00000014 [26991.968423] dd1acc9c f741bc8c c0129f57 dd1accb0 f741bc78 c1c13240 f06ee480 f741bc84 [26991.968430] c0102df6 c1c1357c c1903980 f741bc8c c012848b c1905d00 dd495a40 00000001 [26991.968437] Call Trace: [26991.968443] [] ? load_balance_newidle+0x97/0x270 [26991.968455] [] ? __switch_to+0xa6/0x160 [26991.968459] [] ? finish_task_switch+0x2b/0xe0 [26991.968463] [] ? schedule+0x429/0x790 [26991.968467] [] ? mcount_call+0x5/0x16 [26991.968472] [] ? snd_ctl_notify+0x23/0x1c0 [snd] [26991.968484] [] ? _spin_lock_irqsave+0x31/0x40 [26991.968488] [] ? unfreeze_slab+0x7d/0xc0 [26991.968493] [] ? _spin_lock+0xd/0x10 [26991.968497] [] ? __slab_alloc+0xd4/0x260 [26991.968501] [] ? device_create_vargs+0x57/0xc0 [26991.968506] [] ? device_create_vargs+0xa3/0xc0 [26991.968510] [] ? device_create+0x2d/0x30 [26991.968516] [] ? snd_card_register+0xfd/0x320 [snd] [26991.968525] [] ? snd_hda_build_controls+0x9c/0x9e [snd_hda_intel] [26991.968540] [] ? azx_probe+0x9aa/0xbc0 [snd_hda_intel] [26991.968553] [] ? sysfs_add_one+0x18/0x50 [26991.968558] [] ? azx_get_response+0x0/0x240 [snd_hda_intel] [26991.968568] [] ? azx_power_notify+0x0/0x90 [snd_hda_intel] [26991.968581] [] ? pci_device_probe+0x5e/0x80 [26991.968587] [] ? really_probe+0x59/0x190 [26991.968591] [] ? pci_match_device+0xc6/0xd0 [26991.968598] [] ? driver_probe_device+0x43/0x60 [26991.968601] [] ? __driver_attach+0x79/0x80 [26991.968606] [] ? bus_for_each_dev+0x53/0x80 [26991.968610] [] ? pci_device_remove+0x0/0x40 [26991.968614] [] ? driver_attach+0x1e/0x20 [26991.968618] [] ? __driver_attach+0x0/0x80 [26991.968622] [] ? bus_add_driver+0x1b7/0x230 [26991.968627] [] ? pci_device_remove+0x0/0x40 [26991.968631] [] ? driver_register+0x6e/0x150 [26991.968636] [] ? alsa_card_azx_init+0x0/0x1e [snd_hda_intel] [26991.968648] [] ? __pci_register_driver+0x4f/0x90 [26991.968652] [] ? alsa_card_azx_init+0x0/0x1e [snd_hda_intel] [26991.968662] [] ? alsa_card_azx_init+0x1c/0x1e [snd_hda_intel] [26991.968671] [] ? _stext+0x30/0x160 [26991.968680] [] ? sys_init_module+0x88/0x1b0 [26991.968685] [] ? sysenter_do_call+0x12/0x2f [26991.968690] ======================= [26991.968692] Code: d2 89 85 fc fe ff ff 89 95 f8 fe ff ff 0f 88 5e 07 00 00 8b 85 fc fe ff ff 03 85 f8 fe ff ff 89 85 08 ff ff ff 0f 82 2e 03 00 00 <0f> b6 0b 8b b5 fc fe ff ff 84 c9 74 36 31 ff 80 f9 25 89 b5 04 [26991.968728] EIP: [] vsnprintf+0x3a/0x7b0 SS:ESP 0068:f741bc20 [26991.968739] ---[ end trace 1a121a1447b8167b ]---