BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffffa016be4b>] ext4_mb_good_group+0x39/0xcd [ext4]
PGD 12ac22067 PUD 12de5f067 PMD 0 
Oops: 0000 [#1] SMP 
CPU 0 
Modules linked in: parport_pc ppdev lp parport bnep rfcomm bluetooth cpufreq_conservative cpufreq_userspace cpufreq_powersave cpufreq_stats uinput fuse nfsd nfs nfs_acl auth_rpcgss fscache lockd sunrpc ext3 jbd ext2 loop kvm_intel kvm snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm arc4 snd_page_alloc snd_seq_midi snd_seq_midi_event snd_rawmidi iwlwifi snd_seq psmouse snd_seq_device iTCO_wdt pcspkr serio_raw snd_timer evdev coretemp iTCO_vendor_support i2c_i801 mac80211 battery thinkpad_acpi i915 acpi_cpufreq tpm_tis nvram cfg80211 tpm tpm_bios rfkill ac power_supply snd drm_kms_helper drm mperf i2c_algo_bit wmi i2c_core video soundcore processor button ext4 crc16 jbd2 mbcache sha256_generic cryptd aes_x86_64 aes_generic cbc dm_crypt dm_mod sg sd_mod crc_t10dif thermal thermal_sys ahci libahci uhci_hcd libata ehci_hcd scsi_mod usbcore usb_common e1000e [last unloaded: scsi_wait_scan]

Pid: 3848, comm: firefox-bin Not tainted 3.2.0-3-amd64 #1 LENOVO 7465CTO/7465CTO
RIP: 0010:[<ffffffffa016be4b>]  [<ffffffffa016be4b>] ext4_mb_good_group+0x39/0xcd [ext4]
RSP: 0018:ffff88012deed8c8  EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8800b89248d8 RCX: 0000000000000002
RDX: ffff88012ac5e000 RSI: 0000000000000058 RDI: ffff8801363c0400
RBP: 0000000000000158 R08: ffff880116a0a458 R09: ffff880116a0a458
R10: ffff880116a0a458 R11: ffff880116a0a458 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8801363c0400 R15: 0000000000000000
FS:  00007fa73bafe700(0000) GS:ffff88013bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000012d2c0000 CR4: 00000000000406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process firefox-bin (pid: 3848, threadinfo ffff88012deec000, task ffff880132e271e0)
Stack:
ffff880116a0a458 ffff8800b89248d8 ffff880132e97800 ffff8801363c0400
0000000000000000 0000000000000150 0000000000000158 ffffffffa016d397
0000000300000000 ffff880132e97af8 00000000ffffffff ffff880132e271e0
Call Trace:
[<ffffffffa016d397>] ? ext4_mb_regular_allocator+0x110/0x264 [ext4]
[<ffffffff81036457>] ? should_resched+0x5/0x23
[<ffffffffa016e50a>] ? ext4_mb_new_blocks+0x1c2/0x403 [ext4]
[<ffffffffa016900f>] ? __ext4_handle_dirty_metadata+0xd7/0xe8 [ext4]
[<ffffffffa0171eab>] ? ext4_alloc_branch+0x1ab/0x468 [ext4]
[<ffffffffa012fbf1>] ? jbd2_journal_stop+0x209/0x21b [jbd2]
[<ffffffffa0172922>] ? ext4_ind_map_blocks+0x289/0x4a6 [ext4]
[<ffffffffa01484be>] ? ext4_da_write_end+0x1f1/0x232 [ext4]
[<ffffffff810bd5d9>] ? release_pages+0x68/0x14d
[<ffffffff810bd5d9>] ? release_pages+0x68/0x14d
[<ffffffff811ad099>] ? __lookup_tag+0xb6/0x120
[<ffffffffa0145637>] ? ext4_map_blocks+0x114/0x1f0 [ext4]
[<ffffffff811ad80a>] ? radix_tree_gang_lookup_tag_slot+0x77/0x98
[<ffffffff810f3696>] ? mem_cgroup_add_lru_list+0xd/0xaa
[<ffffffffa014858d>] ? mpage_da_map_and_submit+0x8e/0x2f9 [ext4]
[<ffffffffa0148adf>] ? write_cache_pages_da+0x214/0x2c5 [ext4]
[<ffffffffa0148e32>] ? ext4_da_writepages+0x2a2/0x45b [ext4]
[<ffffffff810b4cd0>] ? __filemap_fdatawrite_range+0x4b/0x50
[<ffffffffa01415aa>] ? ext4_release_file+0x1b/0x93 [ext4]
[<ffffffff810fa30d>] ? fput+0xf9/0x1a1
[<ffffffff810f8036>] ? filp_close+0x62/0x6a
[<ffffffff810f80cc>] ? sys_close+0x8e/0xcb
[<ffffffff8134fc92>] ? system_call_fastpath+0x16/0x1b
Code: 53 48 89 fb 41 52 4c 8b 77 08 49 8b 86 b0 02 00 00 4c 89 f7 44 8b b8 20 03 00 00 e8 fd dc ff ff 41 83 fd 03 49 89 c4 76 02 0f 0b <48> 8b 00 a8 01 74 0e 89 ee 4c 89 f7 e8 18 fe ff ff 85 c0 75 69 
RIP  [<ffffffffa016be4b>] ext4_mb_good_group+0x39/0xcd [ext4]
RSP <ffff88012deed8c8>
CR2: 0000000000000000
---[ end trace 4be76e42fc66006a ]---