[22968.527544] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[22968.527728] IP: [<ffffffff814401d0>] sd_revalidate_disk+0x30/0x2a0
[22968.527874] PGD 6b531067 PUD 304d1067 PMD 0
[22968.527982] Oops: 0000 [#1] SMP
[22968.528021] CPU 1
[22968.528021] Modules linked in: keucr(C) ums_eneub6250 usbhid hid nls_iso8859_1 nls_cp437 vfat fat usb_storage uas bnep rfcomm bluetooth parport_pc ppdev lp parport binfmt_misc dm_crypt bcma arc4 joydev acer_wmi sparse_keymap snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm snd_seq_midi snd_rawmidi brcmsmac snd_seq_midi_event mac80211 snd_seq snd_timer snd_seq_device psmouse snd brcmutil serio_raw cfg80211 uvcvideo videodev v4l2_compat_ioctl32 crc8 soundcore cordic snd_page_alloc coretemp i915 atl1c drm_kms_helper drm wmi i2c_algo_bit video
[22968.528021]
[22968.528021] Pid: 15243, comm: blkid Tainted: G C 3.2.0-4-generic #10-Ubuntu eMachines eM350/eM350
[22968.528021] RIP: 0010:[<ffffffff814401d0>] [<ffffffff814401d0>] sd_revalidate_disk+0x30/0x2a0
[22968.529680] RSP: 0000:ffff88007abf5b08 EFLAGS: 00010246
[22968.529680] RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff880018532780
[22968.529680] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff8800184b3c00
[22968.529680] RBP: ffff88007abf5b28 R08: 0000000800000000 R09: 00000008ffffffff
[22968.529680] R10: 0000000000000000 R11: ffffc90000203000 R12: ffff8800184b3c00
[22968.529680] R13: 00000000ffffff85 R14: ffff880079aa3418 R15: ffff8800184b3c00
[22968.529680] FS: 00007ff964d08760(0000) GS:ffff88007f280000(0000) knlGS:0000000000000000
[22968.529680] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[22968.529680] CR2: 0000000000000008 CR3: 000000006b35c000 CR4: 00000000000006e0
[22968.529680] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[22968.540642] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[22968.540642] Process blkid (pid: 15243, threadinfo ffff88007abf4000, task ffff8800783ddc40)
[22968.548314] Stack:
[22968.548314] ffff880079aa3400 ffff8800184b3c00 00000000ffffff85 ffff880079aa3418
[22968.548314] ffff88007abf5ba8 ffffffff811e2d8a ffff8800184b3c0c ffff8800184b3c78
[22968.548314] 000000007abf5b68 ffff880079aa3400 ffff8800184b2000 ffff8800184b3c00
[22968.548314] Call Trace:
[22968.548314] [<ffffffff811e2d8a>] rescan_partitions+0xaa/0x300
[22968.548314] [<ffffffff811aed6c>] __blkdev_get+0x2bc/0x420
[22968.577994] [<ffffffff811aef2e>] blkdev_get+0x5e/0x1e0
[22968.577994] [<ffffffff811af10d>] blkdev_open+0x5d/0x80
[22968.577994] [<ffffffff81174520>] __dentry_open+0x290/0x360
[22968.577994] [<ffffffff811af0b0>] ? blkdev_get+0x1e0/0x1e0
[22968.577994] [<ffffffff8129a63c>] ? security_inode_permission+0x1c/0x30
[22968.577994] [<ffffffff81175c1d>] nameidata_to_filp+0xad/0xb0
[22968.577994] [<ffffffff811849f8>] do_last+0x3f8/0x730
[22968.577994] [<ffffffff811860d1>] path_openat+0xd1/0x3f0
[22968.577994] [<ffffffff8113a159>] ? __pte_alloc+0xa9/0x160
[22968.577994] [<ffffffff81186512>] do_filp_open+0x42/0xa0
[22968.577994] [<ffffffff81314e11>] ? strncpy_from_user+0x31/0x40
[22968.577994] [<ffffffff8118186a>] ? do_getname+0x10a/0x180
[22968.577994] [<ffffffff8165307e>] ? _raw_spin_lock+0xe/0x20
[22968.577994] [<ffffffff81193797>] ? alloc_fd+0xf7/0x150
[22968.577994] [<ffffffff81175d0d>] do_sys_open+0xed/0x220
[22968.577994] [<ffffffff81175e60>] sys_open+0x20/0x30
[22968.577994] [<ffffffff8165b542>] system_call_fastpath+0x16/0x1b
[22968.577994] Code: 83 ec 20 48 89 5d e0 4c 89 65 e8 4c 89 6d f0 4c 89 75 f8 66 66 66 66 90 8b 05 1d 84 ad 00 48 8b 9f 38 03 00 00 49 89 fc c1 e8 15 <4c> 8b 6b 08 83 e0 07 83 f8 03 0f 87 0d 02 00 00 41 8b 85 70 06
[22968.577994] RIP [<ffffffff814401d0>] sd_revalidate_disk+0x30/0x2a0
[22968.577994] RSP <ffff88007abf5b08>
[22968.577994] CR2: 0000000000000008
[22968.715921] ---[ end trace caa3d18ab9f7f3c4 ]---
[22968.768165] usb 1-1: USB disconnect, device number 115