Comment 30 for bug 1296660

reproducible with 3.13.0-40-generic
Ubuntu 3.13.0-40.69~precise1-generic 3.13.11.10

Dec 5 16:49:56 ubuntu kernel: [ 21.340139] [drm] AST 2300 detected
Dec 5 16:49:56 ubuntu kernel: [ 21.340183] [drm] dram 1632000000 1 16 00800000
Dec 5 16:49:56 ubuntu kernel: [ 21.340211] [TTM] Zone kernel: Available graphics memory: 65964816 kiB
Dec 5 16:49:56 ubuntu kernel: [ 21.340211] [TTM] Zone dma32: Available graphics memory: 2097152 kiB
Dec 5 16:49:56 ubuntu kernel: [ 21.340212] [TTM] Initializing pool allocator
Dec 5 16:49:56 ubuntu kernel: [ 21.340214] [TTM] Initializing DMA pool allocator
Dec 5 16:49:56 ubuntu kernel: [ 21.354338] checking generic (c7000000 130000) vs hw (c7000000 800000)
Dec 5 16:49:56 ubuntu kernel: [ 21.354339] fb: conflicting fb hw usage astdrmfb vs VESA VGA - removing generic driver
Dec 5 16:49:56 ubuntu kernel: [ 21.394467] Console: switching to colour dummy device 80x25
Dec 5 16:49:56 ubuntu kernel: [ 21.394513] BUG: unable to handle kernel NULL pointer dereference at 0000000000000138
Dec 5 16:49:56 ubuntu kernel: [ 21.394517] IP: [<ffffffff8147abd4>] con_set_unimap+0x34/0x2a0
Dec 5 16:49:56 ubuntu kernel: [ 21.394518] PGD 10267e2067 PUD 1025232067 PMD 0
Dec 5 16:49:56 ubuntu kernel: [ 21.394519] Oops: 0000 [#1] SMP
Dec 5 16:49:56 ubuntu kernel: [ 21.394527] Modules linked in: ast(+) ttm drm_kms_helper drm gpio_ich sysimgblt sysfillrect syscopyarea shpchp lpc_ich wmi joydev ipmi_si parport_pc ppdev mac_hid acpi_pad lp parport hid_generic usbhid hid mpt2sas igb dca ahci scsi_transport_sas i2c_algo_bit raid_class ptp libahci pps_core
Dec 5 16:49:56 ubuntu kernel: [ 21.394528] CPU: 4 PID: 1649 Comm: setfont Not tainted 3.13.0-40-generic #69~precise1-Ubuntu
Dec 5 16:49:56 ubuntu kernel: [ 21.394529] Hardware name: Quanta Computer Inc T41S-2U/S2S, BIOS S2S_3A14 09/19/2014
Dec 5 16:49:56 ubuntu kernel: [ 21.394529] task: ffff88202467c800 ti: ffff8820270da000 task.ti: ffff8820270da000
Dec 5 16:49:56 ubuntu kernel: [ 21.394531] RIP: 0010:[<ffffffff8147abd4>] [<ffffffff8147abd4>] con_set_unimap+0x34/0x2a0
Dec 5 16:49:56 ubuntu kernel: [ 21.394531] RSP: 0018:ffff8820270dbd18 EFLAGS: 00010246
Dec 5 16:49:56 ubuntu kernel: [ 21.394532] RAX: ffff8820262a8308 RBX: 0000000000004b67 RCX: 0000000000000000
Dec 5 16:49:56 ubuntu kernel: [ 21.394532] RDX: ffff8820262a8000 RSI: 0000000000000296 RDI: 0000000000000000
Dec 5 16:49:56 ubuntu kernel: [ 21.394533] RBP: ffff8820270dbd98 R08: ffff8820270da000 R09: 0000000000000001
Dec 5 16:49:56 ubuntu kernel: [ 21.394533] R10: 0000000000000020 R11: 0000000000000000 R12: 00000000ffffffff
Dec 5 16:49:56 ubuntu kernel: [ 21.394533] R13: 00000000021f9b10 R14: 0000000000000001 R15: 0000000000000000
Dec 5 16:49:56 ubuntu kernel: [ 21.394534] FS: 00007f9209142700(0000) GS:ffff88103fc80000(0000) knlGS:0000000000000000
Dec 5 16:49:56 ubuntu kernel: [ 21.394534] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Dec 5 16:49:56 ubuntu kernel: [ 21.394535] CR2: 0000000000000138 CR3: 000000101f230000 CR4: 00000000001407e0
Dec 5 16:49:56 ubuntu kernel: [ 21.394535] Stack:
Dec 5 16:49:56 ubuntu kernel: [ 21.394537] 0000000000000286 0000000000000000 ffff8820270dbd58 ffffffff8132657b
Dec 5 16:49:56 ubuntu kernel: [ 21.394539] ffff88202467c800 00000000fffffdfd ffff8820262a8000 0000000000000001
Dec 5 16:49:56 ubuntu kernel: [ 21.394540] 02e18820270dbd68 ffff8820262a8000 ffff8820270dbd88 0000000000004b67
Dec 5 16:49:56 ubuntu kernel: [ 21.394540] Call Trace:
Dec 5 16:49:56 ubuntu kernel: [ 21.394545] [<ffffffff8132657b>] ? apparmor_capable+0x2b/0x110
Dec 5 16:49:56 ubuntu kernel: [ 21.394547] [<ffffffff8147485d>] vt_ioctl+0xfdd/0x11d0
Dec 5 16:49:56 ubuntu kernel: [ 21.394551] [<ffffffff81184f83>] ? handle_mm_fault+0xb3/0x160
Dec 5 16:49:56 ubuntu kernel: [ 21.394554] [<ffffffff81467e98>] tty_ioctl+0x298/0x8f0
Dec 5 16:49:56 ubuntu kernel: [ 21.394556] [<ffffffff811894c0>] ? remove_vma+0x80/0xb0
Dec 5 16:49:56 ubuntu kernel: [ 21.394558] [<ffffffff811dd415>] do_vfs_ioctl+0x75/0x2c0
Dec 5 16:49:56 ubuntu kernel: [ 21.394559] [<ffffffff811dd6f1>] SyS_ioctl+0x91/0xb0
Dec 5 16:49:56 ubuntu kernel: [ 21.394560] [<ffffffff8118b839>] ? vm_munmap+0x59/0x70
Dec 5 16:49:56 ubuntu kernel: [ 21.394563] [<ffffffff8176bcad>] system_call_fastpath+0x1a/0x1f