also hit this bug:
.......
Oct 29 09:04:14 spb-office kernel: [    8.299240] [drm] Initialized drm 1.1.0 20060810
Oct 29 09:04:14 spb-office kernel: [    8.337211] mei_me 0000:00:16.0: irq 45 for MSI/MSI-X
Oct 29 09:04:14 spb-office kernel: [    8.537626] [drm] Memory usable by graphics device = 2048M
Oct 29 09:04:14 spb-office kernel: [    8.537628] checking generic (e0000000 300000) vs hw (e0000000 10000000)
Oct 29 09:04:14 spb-office kernel: [    8.537629] fb: conflicting fb hw usage inteldrmfb vs VESA VGA - removing generic driver
Oct 29 09:04:14 spb-office kernel: [    8.561832] Console: switching to colour dummy device 80x25
Oct 29 09:04:14 spb-office kernel: [    8.561844] BUG: unable to handle kernel NULL pointer dereference at 0000000000000138
Oct 29 09:04:14 spb-office kernel: [    8.561848] IP: [<ffffffff8145ced2>] con_set_unimap+0x32/0x290
Oct 29 09:04:14 spb-office kernel: [    8.561850] PGD c73dd067 PUD c73db067 PMD 0 
Oct 29 09:04:14 spb-office kernel: [    8.561851] Oops: 0000 [#1] SMP 
Oct 29 09:04:14 spb-office kernel: [    8.561862] Modules linked in: snd_hwdep kvm_intel i915(+) snd_pcm snd_page_alloc kvm crct10dif_pcl
mul mei_me crc32_pclmul drm_kms_helper snd_timer drm mei snd ghash_clmulni_intel soundcore cryptd i2c_algo_bit joydev lpc_ich wmi mac_hid
 video serio_raw lp parport hid_generic usbhid hid ahci psmouse libahci r8169 mii
Oct 29 09:04:14 spb-office kernel: [    8.561864] CPU: 0 PID: 475 Comm: setfont Not tainted 3.13.0-36-generic #63-Ubuntu
Oct 29 09:04:14 spb-office kernel: [    8.561864] Hardware name: System manufacturer System Product Name/P8H61-MX R2.0, BIOS 1102 06/04/2
013
Oct 29 09:04:14 spb-office kernel: [    8.561865] task: ffff88003697e000 ti: ffff8800c600e000 task.ti: ffff8800c600e000
Oct 29 09:04:14 spb-office kernel: [    8.561867] RIP: 0010:[<ffffffff8145ced2>]  [<ffffffff8145ced2>] con_set_unimap+0x32/0x290
Oct 29 09:04:14 spb-office kernel: [    8.561868] RSP: 0018:ffff8800c600fd48  EFLAGS: 00010246
Oct 29 09:04:14 spb-office kernel: [    8.561869] RAX: ffff880035f46f08 RBX: 0000000000c88150 RCX: 0000000000000000
Oct 29 09:04:14 spb-office kernel: [    8.561870] RDX: 0000000000001278 RSI: 0000000000000296 RDI: 0000000000000296
Oct 29 09:04:14 spb-office kernel: [    8.561870] RBP: ffff8800c600fdb0 R08: ffff8800c600e000 R09: 0000000000000001
Oct 29 09:04:14 spb-office kernel: [    8.561871] R10: 0000000000000001 R11: ffff880035b2d6be R12: 0000000000000000
Oct 29 09:04:14 spb-office kernel: [    8.561871] R13: 0000000000004b67 R14: ffff880035f46c00 R15: ffff880035f46c00
Oct 29 09:04:14 spb-office kernel: [    8.561872] FS:  00007f1770436740(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
Oct 29 09:04:14 spb-office kernel: [    8.561873] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 29 09:04:14 spb-office kernel: [    8.561874] CR2: 0000000000000138 CR3: 00000000c71e1000 CR4: 00000000001407f0
Oct 29 09:04:14 spb-office kernel: [    8.561874] Stack:
Oct 29 09:04:14 spb-office kernel: [    8.561876]  ffff8800c600fd78 ffffffff81311dfd ffff88003697e000 0000000000000005
Oct 29 09:04:14 spb-office kernel: [    8.561878]  0000000000004b67 ffff880035f46c00 000001dac600fd88 ffff880035f46c00
Oct 29 09:04:14 spb-office kernel: [    8.561879]  0000000000000000 0000000000000005 0000000000004b67 ffff880035f46c00
Oct 29 09:04:14 spb-office kernel: [    8.561879] Call Trace:
Oct 29 09:04:14 spb-office kernel: [    8.561884]  [<ffffffff81311dfd>] ? apparmor_capable+0x1d/0x130
Oct 29 09:04:14 spb-office kernel: [    8.561887]  [<ffffffff81456d73>] vt_ioctl+0xe83/0x11c0
Oct 29 09:04:14 spb-office kernel: [    8.561889]  [<ffffffff8144a88d>] tty_ioctl+0x26d/0xbb0
Oct 29 09:04:14 spb-office kernel: [    8.561892]  [<ffffffff811d0390>] do_vfs_ioctl+0x2e0/0x4c0
Oct 29 09:04:14 spb-office kernel: [    8.561894]  [<ffffffff8117f9f7>] ? do_munmap+0x297/0x3b0
Oct 29 09:04:14 spb-office kernel: [    8.561895]  [<ffffffff811d05f1>] SyS_ioctl+0x81/0xa0
Oct 29 09:04:14 spb-office kernel: [    8.561897]  [<ffffffff8172efad>] system_call_fastpath+0x1a/0x1f
Oct 29 09:04:14 spb-office kernel: [    8.561906] Code: 89 e5 41 57 49 89 ff 41 56 41 55 41 54 53 48 89 d3 48 83 ec 40 48 89 7d d0 89 75 
cc e8 68 e9 c5 ff 49 8b 87 10 03 00 00 4c 8b 20 <41> 8b 84 24 38 01 00 00 85 c0 0f 85 38 02 00 00 66 83 7d cc 00 
Oct 29 09:04:14 spb-office kernel: [    8.561907] RIP  [<ffffffff8145ced2>] con_set_unimap+0x32/0x290
Oct 29 09:04:14 spb-office kernel: [    8.561907]  RSP <ffff8800c600fd48>
Oct 29 09:04:14 spb-office kernel: [    8.561907] CR2: 0000000000000138
Oct 29 09:04:14 spb-office kernel: [    8.561909] ---[ end trace 5f42f50c9417d000 ]---

and system hangs...