Comment 19 for bug 1423672

This happened to me here as well. Also in a VM.

[ 42.042806] ------------[ cut here ]------------
[ 42.042812] WARNING: CPU: 0 PID: 617 at /build/buildd/linux-3.13.0/fs/ext4/ext4_jbd2.c:259 __ext4_handle_dirty_metadata+0x1a2/0x1c0()
[ 42.042813] Modules linked in: kvm_intel kvm cirrus snd_hda_intel ttm snd_hda_codec snd_hwdep drm_kms_helper serio_raw snd_pcm lp parport snd_page_alloc snd_timer drm snd soundcore syscopyarea sysfillrect sysimgblt i2c_piix4 mac_hid psmouse floppy pata_acpi
[ 42.042826] CPU: 0 PID: 617 Comm: mv Not tainted 3.13.0-45-generic #74-Ubuntu
[ 42.042828] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 42.042829] 0000000000000009 ffff88007acd3ad0 ffffffff81720eb6 0000000000000000
[ 42.042831] ffff88007acd3b08 ffffffff810677cd ffff88007bf53d68 0000000000000000
[ 42.042833] ffff88007b5c4000 ffffffff81835280 0000000000001302 ffff88007acd3b18
[ 42.042835] Call Trace:
[ 42.042839] [<ffffffff81720eb6>] dump_stack+0x45/0x56
[ 42.042842] [<ffffffff810677cd>] warn_slowpath_common+0x7d/0xa0
[ 42.042844] [<ffffffff810678aa>] warn_slowpath_null+0x1a/0x20
[ 42.042846] [<ffffffff8126e862>] __ext4_handle_dirty_metadata+0x1a2/0x1c0
[ 42.042850] [<ffffffff81246a5a>] ? ext4_dirty_inode+0x2a/0x60
[ 42.042853] [<ffffffff81277086>] ext4_free_blocks+0x646/0xbf0
[ 42.042855] [<ffffffff812685b5>] ext4_ext_rm_leaf+0x505/0x8f0
[ 42.042857] [<ffffffff81267527>] ? __ext4_ext_check+0x197/0x370
[ 42.042859] [<ffffffff8126ad00>] ? ext4_ext_remove_space+0xc0/0x7e0
[ 42.042861] [<ffffffff8126af5c>] ext4_ext_remove_space+0x31c/0x7e0
[ 42.042863] [<ffffffff8126d300>] ext4_ext_truncate+0xb0/0xe0
[ 42.042865] [<ffffffff81244eb9>] ext4_truncate+0x379/0x3c0
[ 42.042867] [<ffffffff81245a18>] ext4_evict_inode+0x408/0x4d0
[ 42.042870] [<ffffffff811d8f60>] evict+0xb0/0x1b0
[ 42.042872] [<ffffffff811d9775>] iput+0xf5/0x180
[ 42.042875] [<ffffffff811ce09e>] do_unlinkat+0x18e/0x2b0
[ 42.042878] [<ffffffff8172d2ca>] ? do_page_fault+0x1a/0x70
[ 42.042880] [<ffffffff8172c949>] ? do_async_page_fault+0x29/0xe0
[ 42.042882] [<ffffffff811cf006>] SyS_unlink+0x16/0x20
[ 42.042884] [<ffffffff8173196d>] system_call_fastpath+0x1a/0x1f
[ 42.042885] ---[ end trace 18d6f1c79bfdd3f4 ]---
[ 42.042889] BUG: unable to handle kernel NULL pointer dereference at 0000000000000028
[ 42.042930] IP: [<ffffffff8125d4c1>] __ext4_error_inode+0x31/0x160
[ 42.042961] PGD 7c351067 PUD 79b43067 PMD 0
[ 42.042987] Oops: 0000 [#1] SMP
[ 42.043714] Modules linked in: kvm_intel kvm cirrus snd_hda_intel ttm snd_hda_codec snd_hwdep drm_kms_helper serio_raw snd_pcm lp parport snd_page_alloc snd_timer drm snd soundcore syscopyarea sysfillrect sysimgblt i2c_piix4 mac_hid psmouse floppy pata_acpi
[ 42.045134] CPU: 0 PID: 617 Comm: mv Tainted: G W 3.13.0-45-generic #74-Ubuntu
[ 42.045134] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
[ 42.045134] task: ffff88007accb000 ti: ffff88007acd2000 task.ti: ffff88007acd2000
[ 42.045134] RIP: 0010:[<ffffffff8125d4c1>] [<ffffffff8125d4c1>] __ext4_error_inode+0x31/0x160
[ 42.045134] RSP: 0018:ffff88007acd3a88 EFLAGS: 00010296
[ 42.045134] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000100002
[ 42.045134] RDX: 0000000000001302 RSI: ffffffff81a6e81f RDI: 0000000000000000
[ 42.045134] RBP: ffff88007acd3b18 R08: ffffffff81a78568 R09: 0000000000000005
[ 42.052627] init: failsafe main process (586) killed by TERM signal
[ 42.053861] R10: 00000000ffffffe2 R11: ffff88007acd37fe R12: 0000000000100002
[ 42.053861] R13: ffffffff81835280 R14: 0000000000001302 R15: ffffffff81a78568
[ 42.053861] FS: 00007f1189ff9840(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
[ 42.053861] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 42.053861] CR2: 0000000000000028 CR3: 00000000789d8000 CR4: 00000000000006f0
[ 42.053861] Stack:
[ 42.053861] ffff88007acd3a90 0000000000000103 18d6f1c79bfdd3f4 0000000000002818
[ 42.053861] 000000000000142a 0000000000000092 0000000000000216 ffff88007b5c4000
[ 42.053861] ffff88007acd3b18 ffffffff8126e372 ffffffff810677df ffff88007bf53d68
[ 42.053861] Call Trace:
[ 42.053861] [<ffffffff8126e372>] ? ext4_journal_abort_handle+0x42/0xc0
[ 42.053861] [<ffffffff810677df>] ? warn_slowpath_common+0x8f/0xa0
[ 42.053861] [<ffffffff8126e7cf>] __ext4_handle_dirty_metadata+0x10f/0x1c0
[ 42.053861] [<ffffffff81277086>] ext4_free_blocks+0x646/0xbf0
[ 42.053861] [<ffffffff812685b5>] ext4_ext_rm_leaf+0x505/0x8f0
[ 42.053861] [<ffffffff81267527>] ? __ext4_ext_check+0x197/0x370
[ 42.053861] [<ffffffff8126ad00>] ? ext4_ext_remove_space+0xc0/0x7e0
[ 42.053861] [<ffffffff8126af5c>] ext4_ext_remove_space+0x31c/0x7e0
[ 42.053861] [<ffffffff8126d300>] ext4_ext_truncate+0xb0/0xe0
[ 42.053861] [<ffffffff81244eb9>] ext4_truncate+0x379/0x3c0
[ 42.053861] [<ffffffff81245a18>] ext4_evict_inode+0x408/0x4d0
[ 42.053861] [<ffffffff811d8f60>] evict+0xb0/0x1b0
[ 42.053861] [<ffffffff811d9775>] iput+0xf5/0x180
[ 42.053861] [<ffffffff811ce09e>] do_unlinkat+0x18e/0x2b0
[ 42.053861] [<ffffffff8172d2ca>] ? do_page_fault+0x1a/0x70
[ 42.053861] [<ffffffff8172c949>] ? do_async_page_fault+0x29/0xe0
[ 42.053861] [<ffffffff811cf006>] SyS_unlink+0x16/0x20
[ 42.053861] [<ffffffff8173196d>] system_call_fastpath+0x1a/0x1f
[ 42.053861] Code: 48 89 e5 41 57 4d 89 c7 41 56 41 89 d6 41 55 49 89 f5 48 c7 c6 1f e8 a6 81 41 54 49 89 cc 53 48 89 fb 48 83 ec 68 4c 89 4c 24 60 <48> 8b 47 28 48 8b 57 40 48 8b 80 f8 02 00 00 48 8b 40 68 89 90
[ 42.053861] RIP [<ffffffff8125d4c1>] __ext4_error_inode+0x31/0x160
[ 42.053861] RSP <ffff88007acd3a88>
[ 42.053861] CR2: 0000000000000028
[ 42.054171] ---[ end trace 18d6f1c79bfdd3f5 ]---
[ 42.099720] init: flush-early-job-log main process (590) terminated with status 1
[ 42.372030] type=1400 audit(1425311935.380:8): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/sbin/dhclient" pid=697 comm="apparmor_parser"
[ 42.373936] type=1400 audit(1425311935.380:9): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=697 comm="apparmor_parser"
[ 42.375930] type=1400 audit(1425311935.380:10): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/connman/scripts/dhclient-script" pid=697 comm="apparmor_parser"
[ 42.378329] type=1400 audit(1425311935.384:11): apparmor="STATUS" operation="profile_replace" profile="unconfined" name="/usr/lib/NetworkManager/nm-dhcp-client.action" pid=697 comm="apparmor_parser"
[ 42.722323] init: dmesg main process (734) terminated with status 7
[ 44.410227] init: plymouth-upstart-bridge main process ended, respawning
[ 91.135333] random: nonblocking pool is initialized
[ 302.048091] EXT4-fs (vda1): error count since last fsck: 4
[ 302.048210] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[ 302.048312] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[86807.520203] EXT4-fs (vda1): error count since last fsck: 4
[86807.520466] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[86807.520633] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[173315.040128] EXT4-fs (vda1): error count since last fsck: 4
[173315.040240] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[173315.040408] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[259822.560129] EXT4-fs (vda1): error count since last fsck: 4
[259822.560234] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[259822.560408] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[346330.080128] EXT4-fs (vda1): error count since last fsck: 4
[346330.080241] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[346330.080415] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[432837.600131] EXT4-fs (vda1): error count since last fsck: 4
[432837.600244] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[432837.600423] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756
[519345.120107] EXT4-fs (vda1): error count since last fsck: 4
[519345.120189] EXT4-fs (vda1): initial error at time 1425309788: ext4_journal_check_start:56
[519345.120287] EXT4-fs (vda1): last error at time 1425311935: ext4_mb_generate_buddy:756

Linux hostname 3.13.0-45-generic #74-Ubuntu SMP Tue Jan 13 19:36:28 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux