[1942535.509278] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[1942535.509327] IP: [<ffffffffa0206eb6>] drbd_send_dblock+0xc8/0x336 [drbd]
[1942535.509366] PGD 0
[1942535.509389] Oops: 0000 [#1] SMP
[1942535.509415] last sysfs file: /sys/module/drbd/parameters/cn_idx
[1942535.509443] CPU 1
[1942535.509465] Modules linked in: fuse nfs lockd fscache nfs_acl auth_rpcgss sunrpc dm_snapshot sha1_generic drbd cn crc32c iscsi_trgt crc32c_intel bonding loop snd_pcm snd_timer snd soundcore snd_page_alloc i2c_i801 ioatdma psmouse pcspkr serio_raw evdev button i2c_core processor ext3 jbd mbcache dm_mod usbhid hid uhci_hcd sd_mod ses crc_t10dif enclosure
[1942535.509673] block drbd0: meta connection shut down by peer.
[1942535.509677] block drbd0: peer( Secondary -> Unknown ) conn( Connected -> NetworkFailure ) pdsk( UpToDate -> DUnknown ) susp( 0 -> 1 )
[1942535.509745] block drbd0: asender terminated
[1942535.509748] block drbd0: Terminating asender thread
[1942535.509812]  ehci_hcd megaraid_sas usbcore nls_base scsi_mod thermal igb dca thermal_sys [last unloaded: scsi_wait_scan]
[1942535.509884] Pid: 3254, comm: drbd0_worker Not tainted 2.6.32-5-amd64 #1 X8DTH-i/6/iF/6F
[1942535.509930] RIP: 0010:[<ffffffffa0206eb6>]  [<ffffffffa0206eb6>] drbd_send_dblock+0xc8/0x336 [drbd]
[1942535.509984] RSP: 0018:ffff880322a2ddb0  EFLAGS: 00010212
[1942535.510010] RAX: 0000000000000000 RBX: ffff88033a83e9f0 RCX: ffff880322a2ddd0
[1942535.510053] RDX: ffff88033c0c0a38 RSI: ffff88018b2b72d0 RDI: 000000000a000000
[1942535.510096] RBP: 0000000000000000 R08: 0000000000000020 R09: ffff88033c0c0138
[1942535.510140] R10: ffff88033a83e9f0 R11: 0000000000001000 R12: 0000000000000000
[1942535.510183] R13: ffff88018b2b72d0 R14: ffff88033c0c0000 R15: ffff88033c0c07f8
[1942535.510227] FS:  0000000000000000(0000) GS:ffff88000c220000(0000) knlGS:0000000000000000
[1942535.510272] CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
[1942535.510299] CR2: 0000000000000020 CR3: 0000000001001000 CR4: 00000000000006e0
[1942535.510342] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[1942535.510385] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[1942535.510429] Process drbd0_worker (pid: 3254, threadinfo ffff880322a2c000, task ffff88033a83e9f0)
[1942535.510475] Stack:
[1942535.510495]  1810000067027483 8870141203000000 ffff88018b2b72d0 ffff88033c0c0000
[1942535.510531] <0> ffff880322a2de20 ffffffffa01fc9a3 ffff8803254ebd41 ffff88018b2b7a50
[1942535.510585] <0> ffff88033c0c0000 ffff88033c0c0680 0000000000000008 0000000000000000
[1942535.510654] Call Trace:
[1942535.510682]  [<ffffffffa01fc9a3>] ? __req_mod+0x95f/0x9aa [drbd]
[1942535.510713]  [<ffffffffa01ed87f>] ? w_send_dblock+0x26/0x3e [drbd]
[1942535.510744]  [<ffffffffa01ed1f8>] ? drbd_worker+0x4c3/0x4d0 [drbd]
[1942535.510776]  [<ffffffff812fbeac>] ? schedule_timeout+0xad/0xdd
[1942535.510808]  [<ffffffffa0205395>] ? drbd_thread_setup+0x166/0x227 [drbd]
[1942535.510840]  [<ffffffff81011baa>] ? child_rip+0xa/0x20
[1942535.510868]  [<ffffffff811b89f1>] ? vgacon_cursor+0x0/0x140
[1942535.510900]  [<ffffffffa020522f>] ? drbd_thread_setup+0x0/0x227 [drbd]
[1942535.510929]  [<ffffffff81011ba0>] ? child_rip+0x0/0x20
[1942535.510954] Code: 89 6c 24 10 48 0f c8 48 89 44 24 08 b8 01 00 00 00 f0 0f c1 02 ff c0 41 89 45 68 89 c7 49 8b 45 58 0f cf 41 83 be 30 04 00 00 5e <48> 8b 50 20 7e 43 48 89 d0 83 e0 40 48 83 f8 01 88 d0 19 c9 83
[1942535.511162] RIP  [<ffffffffa0206eb6>] drbd_send_dblock+0xc8/0x336 [drbd]
[1942535.511198]  RSP <ffff880322a2ddb0>
[1942535.511220] CR2: 0000000000000020
[1942535.511568] ---[ end trace 9ec0b3f0d5dc5490 ]---