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    Hello,<br>
    <br>
    <br>
    Lately we have experienced five kernel oopses in our DRBD setup. The
    stack trace is very similar every time.<br>
    <br>
    If you need more information, please let me know. Thank you in
    advance.<br>
    <br>
    <br>
    Kind regards,<br>
    Ben.<br>
    <br>
    <pre>----------

2015-05-05T09:31:02.759829+00:00 uk3 kern.info kernel Linux version 4.0.1-x86_64-linode55 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #3 SMP Wed Apr 29 11:10:11 EDT 2015
2015-05-05T09:31:02.760314+00:00 uk3 kern.info kernel drbd: initialized. Version: 8.4.5 (api:1/proto:86-101)

2015-05-13T14:14:58.163337+00:00 uk3 kern.alert kernel BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
2015-05-13T14:14:58.163365+00:00 uk3 kern.alert kernel IP: [&lt;ffffffff8157804f&gt;] copy_from_iter+0x140/0x24e
2015-05-13T14:14:58.163369+00:00 uk3 kern.warning kernel PGD 759f7067 PUD 77777067 PMD 0 
2015-05-13T14:14:58.163372+00:00 uk3 kern.warning kernel Oops: 0000 [#1] SMP 
2015-05-13T14:14:58.163374+00:00 uk3 kern.warning kernel Modules linked in:
2015-05-13T14:14:58.163390+00:00 uk3 kern.warning kernel CPU: 0 PID: 3606 Comm: drbd_w_db Not tainted 4.0.1-x86_64-linode55 #3
2015-05-13T14:14:58.163392+00:00 uk3 kern.warning kernel task: ffff88007c5071c0 ti: ffff880075bd0000 task.ti: ffff880075bd0000
2015-05-13T14:14:58.163395+00:00 uk3 kern.warning kernel RIP: e030:[&lt;ffffffff8157804f&gt;]  [&lt;ffffffff8157804f&gt;] copy_from_iter+0x140/0x24e
2015-05-13T14:14:58.163397+00:00 uk3 kern.warning kernel RSP: e02b:ffff880075bd3ae0  EFLAGS: 00010286
2015-05-13T14:14:58.163399+00:00 uk3 kern.warning kernel RAX: 0000000000000440 RBX: 0000000000000440 RCX: 0000000000000440
2015-05-13T14:14:58.163401+00:00 uk3 kern.warning kernel RDX: ffff880075bd3c88 RSI: 0000000000000003 RDI: ffff880005f25088
2015-05-13T14:14:58.163403+00:00 uk3 kern.warning kernel RBP: ffff880075bd3c88 R08: 0000000000000000 R09: ffff880005f254c8
2015-05-13T14:14:58.163409+00:00 uk3 kern.warning kernel R10: ffff880005f25088 R11: ffff88007d2149c0 R12: 0000000000000a10
2015-05-13T14:14:58.163411+00:00 uk3 kern.warning kernel R13: ffff8800720f3000 R14: ffff88007c507978 R15: ffff880075ab57c0
2015-05-13T14:14:58.163413+00:00 uk3 kern.warning kernel FS:  0000000000000000(0000) GS:ffff88007d200000(0000) knlGS:ffff880179b40000
2015-05-13T14:14:58.163415+00:00 uk3 kern.warning kernel CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
2015-05-13T14:14:58.163417+00:00 uk3 kern.warning kernel CR2: 0000000000000003 CR3: 00000000771e1000 CR4: 0000000000042660
2015-05-13T14:14:58.163419+00:00 uk3 kern.warning kernel Stack:
2015-05-13T14:14:58.163421+00:00 uk3 kern.warning kernel 00000000000005f0 ffff88002d75f200 0000000000000a10 ffff880075bd3c78
2015-05-13T14:14:58.163422+00:00 uk3 kern.warning kernel 00000000000005f0 ffff8800720f3000 ffff88007c507978 ffff880075ab57c0
2015-05-13T14:14:58.163429+00:00 uk3 kern.warning kernel ffffffff817d0f76 000040000000fa20 ffff880075bd3c88 0000000000000a10
2015-05-13T14:14:58.163430+00:00 uk3 kern.warning kernel Call Trace:
2015-05-13T14:14:58.163432+00:00 uk3 kern.warning kernel [&lt;ffffffff817d0f76&gt;] ? tcp_sendmsg+0x610/0x9b7
2015-05-13T14:14:58.163434+00:00 uk3 kern.warning kernel [&lt;ffffffff816f8787&gt;] ? sock_sendmsg+0x59/0x73
2015-05-13T14:14:58.163436+00:00 uk3 kern.warning kernel [&lt;ffffffff816f87ee&gt;] ? kernel_sendmsg+0x4d/0x5d
2015-05-13T14:14:58.163441+00:00 uk3 kern.warning kernel [&lt;ffffffff81645a3f&gt;] ? drbd_send+0xa2/0x16d
2015-05-13T14:14:58.163473+00:00 uk3 kern.warning kernel [&lt;ffffffff81645b18&gt;] ? drbd_send_all+0xe/0x23
2015-05-13T14:14:58.163481+00:00 uk3 kern.warning kernel [&lt;ffffffff81647099&gt;] ? _drbd_no_send_page+0x47/0x5d
2015-05-13T14:14:58.163483+00:00 uk3 kern.warning kernel [&lt;ffffffff81647671&gt;] ? drbd_send_dblock+0x2e1/0x4ab
2015-05-13T14:14:58.163485+00:00 uk3 kern.warning kernel [&lt;ffffffff8163de54&gt;] ? mod_rq_state+0x463/0x4e1
2015-05-13T14:14:58.163487+00:00 uk3 kern.warning kernel [&lt;ffffffff818f8229&gt;] ? _raw_spin_lock_irq+0xc/0x65
2015-05-13T14:14:58.163503+00:00 uk3 kern.warning kernel [&lt;ffffffff8162c72b&gt;] ? dequeue_work_batch+0x63/0x7d
2015-05-13T14:14:58.163507+00:00 uk3 kern.warning kernel [&lt;ffffffff8162cab6&gt;] ? wait_for_work+0x59/0x2e0
2015-05-13T14:14:58.163509+00:00 uk3 kern.warning kernel [&lt;ffffffff8163044b&gt;] ? w_send_dblock+0xd3/0x139
2015-05-13T14:14:58.163511+00:00 uk3 kern.warning kernel [&lt;ffffffff816315a6&gt;] ? drbd_worker+0x124/0x302
2015-05-13T14:14:58.163524+00:00 uk3 kern.warning kernel [&lt;ffffffff81644d53&gt;] ? w_complete+0x13/0x13
2015-05-13T14:14:58.163526+00:00 uk3 kern.warning kernel [&lt;ffffffff81644d9a&gt;] ? drbd_thread_setup+0x47/0x10c
2015-05-13T14:14:58.163528+00:00 uk3 kern.warning kernel [&lt;ffffffff81644d53&gt;] ? w_complete+0x13/0x13
2015-05-13T14:14:58.163530+00:00 uk3 kern.warning kernel [&lt;ffffffff810ecfb0&gt;] ? kthread+0xca/0xd2
2015-05-13T14:14:58.163532+00:00 uk3 kern.warning kernel [&lt;ffffffff810ecee6&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-05-13T14:14:58.163534+00:00 uk3 kern.warning kernel [&lt;ffffffff818f86d8&gt;] ? ret_from_fork+0x58/0x90
2015-05-13T14:14:58.163536+00:00 uk3 kern.warning kernel [&lt;ffffffff810ecee6&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-05-13T14:14:58.163547+00:00 uk3 kern.warning kernel Code: eb 2b 4c 39 42 08 4c 89 c0 48 0f 46 42 08 48 85 c0 74 1a 49 01 c1 48 8b 32 48 89 c1 4d 89 ca 49 29 c0 48 89 c3 49 29 c2 4c 89 d7 &lt;f3&gt; a4 48 83 c2 10 4d 85 c0 48 8d 42 f0 75 c8 48 3b 58 08 75 05 
2015-05-13T14:14:58.163551+00:00 uk3 kern.alert kernel RIP  [&lt;ffffffff8157804f&gt;] copy_from_iter+0x140/0x24e
2015-05-13T14:14:58.163553+00:00 uk3 kern.warning kernel RSP &lt;ffff880075bd3ae0&gt;
2015-05-13T14:14:58.163555+00:00 uk3 kern.warning kernel CR2: 0000000000000003
2015-05-13T14:14:58.163557+00:00 uk3 kern.warning kernel ---[ end trace 74bd7ba7a08a9e0b ]---

----------

2015-07-08T09:15:05.756460+00:00 uk3 kern.info kernel Linux version 4.1.0-x86_64-linode59 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Mon Jun 22 10:39:23 EDT 2015
2015-07-08T09:15:05.756905+00:00 uk3 kern.info kernel drbd: initialized. Version: 8.4.5 (api:1/proto:86-101)
drbd8-utils:amd64 (8.9.2~rc1-1~bpo70+1)
drbd-utils:amd64 (8.9.2~rc1-1~bpo70+1, automatic)

2015-07-10T18:11:09.971130+00:00 uk3 kern.alert kernel BUG: unable to handle kernel paging request at 0000000000001000
2015-07-10T18:11:09.971162+00:00 uk3 kern.alert kernel IP: [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-10T18:11:09.971164+00:00 uk3 kern.warning kernel PGD 77b46067 PUD 6f0df067 PMD 0 
2015-07-10T18:11:09.971165+00:00 uk3 kern.warning kernel Oops: 0000 [#1] SMP 
2015-07-10T18:11:09.971166+00:00 uk3 kern.warning kernel Modules linked in:
2015-07-10T18:11:09.971167+00:00 uk3 kern.warning kernel CPU: 0 PID: 4516 Comm: drbd_w_db Not tainted 4.1.0-x86_64-linode59 #1
2015-07-10T18:11:09.971169+00:00 uk3 kern.warning kernel Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
2015-07-10T18:11:09.971188+00:00 uk3 kern.warning kernel task: ffff88006f024a40 ti: ffff8800793b0000 task.ti: ffff8800793b0000
2015-07-10T18:11:09.971190+00:00 uk3 kern.warning kernel RIP: 0010:[&lt;ffffffff8158ba60&gt;]  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-10T18:11:09.971191+00:00 uk3 kern.warning kernel RSP: 0018:ffff8800793b3b60  EFLAGS: 00010292
2015-07-10T18:11:09.971192+00:00 uk3 kern.warning kernel RAX: 0000000000000028 RBX: 0000000000000028 RCX: 0000000000000028
2015-07-10T18:11:09.971192+00:00 uk3 kern.warning kernel RDX: ffff8800793b3c90 RSI: 0000000000001000 RDI: ffff8800384eae98
2015-07-10T18:11:09.971193+00:00 uk3 kern.warning kernel RBP: ffff8800793b3c80 R08: 0000000000000000 R09: ffff8800384eaec0
2015-07-10T18:11:09.971194+00:00 uk3 kern.warning kernel R10: ffff8800384eae98 R11: 000000000000bab2 R12: 00000000000005f0
2015-07-10T18:11:09.971195+00:00 uk3 kern.warning kernel R13: ffff880068334800 R14: 00000000000005f0 R15: ffff8800716e3640
2015-07-10T18:11:09.971198+00:00 uk3 kern.warning kernel FS:  0000000000000000(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
2015-07-10T18:11:09.971199+00:00 uk3 kern.warning kernel CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2015-07-10T18:11:09.971200+00:00 uk3 kern.warning kernel CR2: 0000000000001000 CR3: 00000000760ef000 CR4: 00000000001407f0
2015-07-10T18:11:09.971201+00:00 uk3 kern.warning kernel Stack:
2015-07-10T18:11:09.971202+00:00 uk3 kern.warning kernel 00000000000005f0 ffff880073f43200 00000000000005f0 ffff8800793b3c70
2015-07-10T18:11:09.971202+00:00 uk3 kern.warning kernel 0000000000000000 ffff880068334800 00000000000005f0 ffff8800716e3640
2015-07-10T18:11:09.971203+00:00 uk3 kern.warning kernel ffffffff81838006 000040000000f428 ffff8800793b3c80 0000000000000000
2015-07-10T18:11:09.971206+00:00 uk3 kern.warning kernel Call Trace:
2015-07-10T18:11:09.971207+00:00 uk3 kern.warning kernel [&lt;ffffffff81838006&gt;] ? tcp_sendmsg+0x3ee/0x9b4
2015-07-10T18:11:09.971208+00:00 uk3 kern.warning kernel [&lt;ffffffff8175c6de&gt;] ? sock_sendmsg+0x2e/0x3b
2015-07-10T18:11:09.971209+00:00 uk3 kern.warning kernel [&lt;ffffffff81666c4a&gt;] ? drbd_send+0xa5/0x171
2015-07-10T18:11:09.971210+00:00 uk3 kern.warning kernel [&lt;ffffffff81666d24&gt;] ? drbd_send_all+0xe/0x23
2015-07-10T18:11:09.971211+00:00 uk3 kern.warning kernel [&lt;ffffffff816682a5&gt;] ? _drbd_no_send_page+0x47/0x5d
2015-07-10T18:11:09.971212+00:00 uk3 kern.warning kernel [&lt;ffffffff8166887d&gt;] ? drbd_send_dblock+0x2e1/0x4ab
2015-07-10T18:11:09.971213+00:00 uk3 kern.warning kernel [&lt;ffffffff811075ae&gt;] ? __wake_up_common+0x47/0x7d
2015-07-10T18:11:09.971216+00:00 uk3 kern.warning kernel [&lt;ffffffff81107a84&gt;] ? __wake_up+0x3a/0x4b
2015-07-10T18:11:09.971217+00:00 uk3 kern.warning kernel [&lt;ffffffff81651643&gt;] ? w_send_dblock+0xd3/0x139
2015-07-10T18:11:09.971219+00:00 uk3 kern.warning kernel [&lt;ffffffff8165279e&gt;] ? drbd_worker+0x124/0x302
2015-07-10T18:11:09.971219+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-10T18:11:09.971220+00:00 uk3 kern.warning kernel [&lt;ffffffff81665fa2&gt;] ? drbd_thread_setup+0x47/0x10c
2015-07-10T18:11:09.971221+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-10T18:11:09.971222+00:00 uk3 kern.warning kernel [&lt;ffffffff810f088c&gt;] ? kthread+0xca/0xd2
2015-07-10T18:11:09.971226+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-10T18:11:09.971227+00:00 uk3 kern.warning kernel [&lt;ffffffff81962362&gt;] ? ret_from_fork+0x42/0x70
2015-07-10T18:11:09.971228+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-10T18:11:09.971229+00:00 uk3 kern.warning kernel Code: eb 2b 4c 39 42 08 4c 89 c0 48 0f 46 42 08 48 85 c0 74 1a 49 01 c1 48 8b 32 48 89 c1 4d 89 ca 49 29 c0 48 89 c3 49 29 c2 4c 89 d7 &lt;f3&gt; a4 48 83 c2 10 4d 85 c0 48 8d 42 f0 75 c8 48 3b 58 08 75 05 
2015-07-10T18:11:09.971231+00:00 uk3 kern.alert kernel RIP  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-10T18:11:09.971231+00:00 uk3 kern.warning kernel RSP &lt;ffff8800793b3b60&gt;
2015-07-10T18:11:09.971232+00:00 uk3 kern.warning kernel CR2: 0000000000001000
2015-07-10T18:11:09.971233+00:00 uk3 kern.warning kernel ---[ end trace e217b95518b37926 ]---

----------

2015-07-27T06:46:57.151773+00:00 uk3 kern.info kernel Linux version 4.1.0-x86_64-linode59 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Mon Jun 22 10:39:23 EDT 2015
2015-07-27T06:46:57.152404+00:00 uk3 kern.info kernel drbd: initialized. Version: 8.4.5 (api:1/proto:86-101)
drbd8-utils:amd64 (8.9.2~rc1-1~bpo70+1)
drbd-utils:amd64 (8.9.2~rc1-1~bpo70+1, automatic)

2015-07-27T07:44:17.576075+00:00 uk3 kern.alert kernel BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
2015-07-27T07:44:17.576106+00:00 uk3 kern.alert kernel IP: [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T07:44:17.576108+00:00 uk3 kern.warning kernel PGD 759b0067 PUD 759b1067 PMD 0 
2015-07-27T07:44:17.576109+00:00 uk3 kern.warning kernel Oops: 0000 [#1] SMP 
2015-07-27T07:44:17.576110+00:00 uk3 kern.warning kernel Modules linked in:
2015-07-27T07:44:17.576112+00:00 uk3 kern.warning kernel CPU: 0 PID: 4448 Comm: drbd_w_db Not tainted 4.1.0-x86_64-linode59 #1
2015-07-27T07:44:17.576114+00:00 uk3 kern.warning kernel Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
2015-07-27T07:44:17.576116+00:00 uk3 kern.warning kernel task: ffff880075a87380 ti: ffff880075a68000 task.ti: ffff880075a68000
2015-07-27T07:44:17.576122+00:00 uk3 kern.warning kernel RIP: 0010:[&lt;ffffffff8158ba60&gt;]  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T07:44:17.576123+00:00 uk3 kern.warning kernel RSP: 0018:ffff880075a6bb60  EFLAGS: 00010282
2015-07-27T07:44:17.576125+00:00 uk3 kern.warning kernel RAX: 00000000000005f0 RBX: 00000000000005f0 RCX: 00000000000005f0
2015-07-27T07:44:17.576127+00:00 uk3 kern.warning kernel RDX: ffff880075a6bc80 RSI: 0000000000000003 RDI: ffff88006c9e8aa8
2015-07-27T07:44:17.576128+00:00 uk3 kern.warning kernel RBP: ffff880075a6bc80 R08: 0000000000000190 R09: ffff88006c9e9098
2015-07-27T07:44:17.576174+00:00 uk3 kern.warning kernel R10: ffff88006c9e8aa8 R11: 00000000000005a8 R12: 0000000000000a10
2015-07-27T07:44:17.576179+00:00 uk3 kern.warning kernel R13: ffff8800788fd000 R14: ffff880075a87b40 R15: ffff88007bae3e00
2015-07-27T07:44:17.576182+00:00 uk3 kern.warning kernel FS:  0000000000000000(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
2015-07-27T07:44:17.576184+00:00 uk3 kern.warning kernel CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2015-07-27T07:44:17.576186+00:00 uk3 kern.warning kernel CR2: 0000000000000003 CR3: 000000007597a000 CR4: 00000000001407f0
2015-07-27T07:44:17.576187+00:00 uk3 kern.warning kernel Stack:
2015-07-27T07:44:17.576210+00:00 uk3 kern.warning kernel 00000000000005f0 ffff8800788fca00 0000000000000a10 ffff880075a6bc70
2015-07-27T07:44:17.576212+00:00 uk3 kern.warning kernel 00000000000005f0 ffff8800788fd000 ffff880075a87b40 ffff88007bae3e00
2015-07-27T07:44:17.576213+00:00 uk3 kern.warning kernel ffffffff81838225 000040000000f6e0 ffff880075a6bc80 0000000000000a10
2015-07-27T07:44:17.576213+00:00 uk3 kern.warning kernel Call Trace:
2015-07-27T07:44:17.576215+00:00 uk3 kern.warning kernel [&lt;ffffffff81838225&gt;] ? tcp_sendmsg+0x60d/0x9b4
2015-07-27T07:44:17.576216+00:00 uk3 kern.warning kernel [&lt;ffffffff8175c6de&gt;] ? sock_sendmsg+0x2e/0x3b
2015-07-27T07:44:17.576217+00:00 uk3 kern.warning kernel [&lt;ffffffff81666c4a&gt;] ? drbd_send+0xa5/0x171
2015-07-27T07:44:17.576220+00:00 uk3 kern.warning kernel [&lt;ffffffff81666d24&gt;] ? drbd_send_all+0xe/0x23
2015-07-27T07:44:17.576222+00:00 uk3 kern.warning kernel [&lt;ffffffff816682a5&gt;] ? _drbd_no_send_page+0x47/0x5d
2015-07-27T07:44:17.576223+00:00 uk3 kern.warning kernel [&lt;ffffffff8166887d&gt;] ? drbd_send_dblock+0x2e1/0x4ab
2015-07-27T07:44:17.576224+00:00 uk3 kern.warning kernel [&lt;ffffffff81107a84&gt;] ? __wake_up+0x3a/0x4b
2015-07-27T07:44:17.576225+00:00 uk3 kern.warning kernel [&lt;ffffffff81651643&gt;] ? w_send_dblock+0xd3/0x139
2015-07-27T07:44:17.576226+00:00 uk3 kern.warning kernel [&lt;ffffffff8165279e&gt;] ? drbd_worker+0x124/0x302
2015-07-27T07:44:17.576226+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-27T07:44:17.576227+00:00 uk3 kern.warning kernel [&lt;ffffffff81665fa2&gt;] ? drbd_thread_setup+0x47/0x10c
2015-07-27T07:44:17.576231+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-27T07:44:17.576232+00:00 uk3 kern.warning kernel [&lt;ffffffff810f088c&gt;] ? kthread+0xca/0xd2
2015-07-27T07:44:17.576233+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-27T07:44:17.576234+00:00 uk3 kern.warning kernel [&lt;ffffffff81962362&gt;] ? ret_from_fork+0x42/0x70
2015-07-27T07:44:17.576235+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-27T07:44:17.576237+00:00 uk3 kern.warning kernel Code: eb 2b 4c 39 42 08 4c 89 c0 48 0f 46 42 08 48 85 c0 74 1a 49 01 c1 48 8b 32 48 89 c1 4d 89 ca 49 29 c0 48 89 c3 49 29 c2 4c 89 d7 &lt;f3&gt; a4 48 83 c2 10 4d 85 c0 48 8d 42 f0 75 c8 48 3b 58 08 75 05 
2015-07-27T07:44:17.576238+00:00 uk3 kern.alert kernel RIP  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T07:44:17.576241+00:00 uk3 kern.warning kernel RSP &lt;ffff880075a6bb60&gt;
2015-07-27T07:44:17.576242+00:00 uk3 kern.warning kernel CR2: 0000000000000003
2015-07-27T07:44:17.576243+00:00 uk3 kern.warning kernel ---[ end trace 72c4b2b13ae06bb9 ]---

----------

2015-07-27T06:50:01.146390+00:00 uk4 kern.info kernel Linux version 4.1.0-x86_64-linode59 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Mon Jun 22 10:39:23 EDT 2015
2015-07-27T06:50:01.147014+00:00 uk4 kern.info kernel drbd: initialized. Version: 8.4.5 (api:1/proto:86-101)
drbd8-utils:amd64 (8.9.2~rc1-1~bpo70+1)
drbd-utils:amd64 (8.9.2~rc1-1~bpo70+1, automatic)

2015-07-27T18:04:49.795904+00:00 uk4 kern.alert kernel BUG: unable to handle kernel NULL pointer dereference at 0000000000000003
2015-07-27T18:04:49.795931+00:00 uk4 kern.alert kernel IP: [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T18:04:49.795933+00:00 uk4 kern.warning kernel PGD 77e8d067 PUD 78b0c067 PMD 0 
2015-07-27T18:04:49.795935+00:00 uk4 kern.warning kernel Oops: 0000 [#1] SMP 
2015-07-27T18:04:49.795936+00:00 uk4 kern.warning kernel Modules linked in:
2015-07-27T18:04:49.795938+00:00 uk4 kern.warning kernel CPU: 0 PID: 4166 Comm: drbd_w_db Not tainted 4.1.0-x86_64-linode59 #1
2015-07-27T18:04:49.795940+00:00 uk4 kern.warning kernel Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20150316_085822-nilsson.home.kraxel.org 04/01/2014
2015-07-27T18:04:49.795954+00:00 uk4 kern.warning kernel task: ffff8800741498c0 ti: ffff88007b7f0000 task.ti: ffff88007b7f0000
2015-07-27T18:04:49.795956+00:00 uk4 kern.warning kernel RIP: 0010:[&lt;ffffffff8158ba60&gt;]  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T18:04:49.795957+00:00 uk4 kern.warning kernel RSP: 0018:ffff88007b7f3b60  EFLAGS: 00010282
2015-07-27T18:04:49.795959+00:00 uk4 kern.warning kernel RAX: 00000000000005f0 RBX: 00000000000005f0 RCX: 00000000000005f0
2015-07-27T18:04:49.795995+00:00 uk4 kern.warning kernel RDX: ffff88007b7f3c80 RSI: 0000000000000003 RDI: ffff880002af9be0
2015-07-27T18:04:49.795997+00:00 uk4 kern.warning kernel RBP: ffff88007b7f3c80 R08: 00000000000003f0 R09: ffff880002afa1d0
2015-07-27T18:04:49.795999+00:00 uk4 kern.warning kernel R10: ffff880002af9be0 R11: 00000000000005a8 R12: 0000000000000a10
2015-07-27T18:04:49.796003+00:00 uk4 kern.warning kernel R13: ffff88006a7d8e00 R14: ffff88007414a080 R15: ffff880077421f00
2015-07-27T18:04:49.796004+00:00 uk4 kern.warning kernel FS:  0000000000000000(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000
2015-07-27T18:04:49.796006+00:00 uk4 kern.warning kernel CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
2015-07-27T18:04:49.796007+00:00 uk4 kern.warning kernel CR2: 0000000000000003 CR3: 0000000077e8c000 CR4: 00000000001407f0
2015-07-27T18:04:49.796008+00:00 uk4 kern.warning kernel Stack:
2015-07-27T18:04:49.796009+00:00 uk4 kern.warning kernel 00000000000005f0 ffff88006a7d9e00 0000000000000a10 ffff88007b7f3c70
2015-07-27T18:04:49.796010+00:00 uk4 kern.warning kernel 00000000000005f0 ffff88006a7d8e00 ffff88007414a080 ffff880077421f00
2015-07-27T18:04:49.796014+00:00 uk4 kern.warning kernel ffffffff81838225 000040000000f480 ffff88007b7f3c80 0000000000000a10
2015-07-27T18:04:49.796015+00:00 uk4 kern.warning kernel Call Trace:
2015-07-27T18:04:49.796016+00:00 uk4 kern.warning kernel [&lt;ffffffff81838225&gt;] ? tcp_sendmsg+0x60d/0x9b4
2015-07-27T18:04:49.796017+00:00 uk4 kern.warning kernel [&lt;ffffffff8175c6de&gt;] ? sock_sendmsg+0x2e/0x3b
2015-07-27T18:04:49.796019+00:00 uk4 kern.warning kernel [&lt;ffffffff81666c4a&gt;] ? drbd_send+0xa5/0x171
2015-07-27T18:04:49.796020+00:00 uk4 kern.warning kernel [&lt;ffffffff81666d24&gt;] ? drbd_send_all+0xe/0x23
2015-07-27T18:04:49.796022+00:00 uk4 kern.warning kernel [&lt;ffffffff816682a5&gt;] ? _drbd_no_send_page+0x47/0x5d
2015-07-27T18:04:49.796024+00:00 uk4 kern.warning kernel [&lt;ffffffff8166887d&gt;] ? drbd_send_dblock+0x2e1/0x4ab
2015-07-27T18:04:49.796027+00:00 uk4 kern.warning kernel [&lt;ffffffff81107a84&gt;] ? __wake_up+0x3a/0x4b
2015-07-27T18:04:49.796029+00:00 uk4 kern.warning kernel [&lt;ffffffff81651643&gt;] ? w_send_dblock+0xd3/0x139
2015-07-27T18:04:49.796030+00:00 uk4 kern.warning kernel [&lt;ffffffff8165279e&gt;] ? drbd_worker+0x124/0x302
2015-07-27T18:04:49.796032+00:00 uk4 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-27T18:04:49.796033+00:00 uk4 kern.warning kernel [&lt;ffffffff81665fa2&gt;] ? drbd_thread_setup+0x47/0x10c
2015-07-27T18:04:49.796034+00:00 uk4 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-07-27T18:04:49.796036+00:00 uk4 kern.warning kernel [&lt;ffffffff810f088c&gt;] ? kthread+0xca/0xd2
2015-07-27T18:04:49.796040+00:00 uk4 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-27T18:04:49.796041+00:00 uk4 kern.warning kernel [&lt;ffffffff81962362&gt;] ? ret_from_fork+0x42/0x70
2015-07-27T18:04:49.796042+00:00 uk4 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-07-27T18:04:49.796045+00:00 uk4 kern.warning kernel Code: eb 2b 4c 39 42 08 4c 89 c0 48 0f 46 42 08 48 85 c0 74 1a 49 01 c1 48 8b 32 48 89 c1 4d 89 ca 49 29 c0 48 89 c3 49 29 c2 4c 89 d7 &lt;f3&gt; a4 48 83 c2 10 4d 85 c0 48 8d 42 f0 75 c8 48 3b 58 08 75 05 
2015-07-27T18:04:49.796046+00:00 uk4 kern.alert kernel RIP  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-07-27T18:04:49.796047+00:00 uk4 kern.warning kernel RSP &lt;ffff88007b7f3b60&gt;
2015-07-27T18:04:49.796048+00:00 uk4 kern.warning kernel CR2: 0000000000000003
2015-07-27T18:04:49.796052+00:00 uk4 kern.warning kernel ---[ end trace 1277a4d533113ace ]---

----------

2015-08-05T14:01:37.789073+00:00 uk3 kern.info kernel Linux version 4.1.0-x86_64-linode59 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Mon Jun 22 10:39:23 EDT 2015
2015-08-05T14:01:37.789801+00:00 uk3 kern.info kernel drbd: initialized. Version: 8.4.5 (api:1/proto:86-101)
drbd8-utils:amd64 (8.9.2~rc1-1~bpo70+1)
drbd-utils:amd64 (8.9.2~rc1-1~bpo70+1, automatic)

2015-08-13T16:39:28.838858+00:00 uk3 kern.alert kernel BUG: unable to handle kernel paging request at 0000000000001000
2015-08-13T16:39:28.838887+00:00 uk3 kern.alert kernel IP: [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-08-13T16:39:28.838890+00:00 uk3 kern.warning kernel PGD 0
2015-08-13T16:39:28.838892+00:00 uk3 kern.warning kernel Oops: 0000 [#1] SMP
2015-08-13T16:39:28.838894+00:00 uk3 kern.warning kernel Modules linked in:
2015-08-13T16:39:28.838896+00:00 uk3 kern.warning kernel CPU: 0 PID: 6121 Comm: drbd_w_db Not tainted 4.1.0-x86_64-linode59 #1
2015-08-13T16:39:28.838899+00:00 uk3 kern.warning kernel task: ffff88007c0d3180 ti: ffff8800776b8000 task.ti: ffff8800776b8000
2015-08-13T16:39:28.838903+00:00 uk3 kern.warning kernel RIP: e030:[&lt;ffffffff8158ba60&gt;]  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-08-13T16:39:28.838907+00:00 uk3 kern.warning kernel RSP: e02b:ffff8800776bbb60  EFLAGS: 00010282
2015-08-13T16:39:28.838909+00:00 uk3 kern.warning kernel RAX: 00000000000004e0 RBX: 00000000000004e0 RCX: 00000000000004e0
2015-08-13T16:39:28.838912+00:00 uk3 kern.warning kernel RDX: ffff8800776bbc90 RSI: 0000000000001000 RDI: ffff880077acd9e0
2015-08-13T16:39:28.838914+00:00 uk3 kern.warning kernel RBP: ffff8800776bbc80 R08: 0000000000000000 R09: ffff880077acdec0
2015-08-13T16:39:28.838916+00:00 uk3 kern.warning kernel R10: ffff880077acd9e0 R11: 00000000000005a8 R12: 00000000000005f0
2015-08-13T16:39:28.838918+00:00 uk3 kern.warning kernel R13: ffff88007c74de00 R14: 00000000000005f0 R15: ffff880000ed5540
2015-08-13T16:39:28.838920+00:00 uk3 kern.warning kernel FS:  0000000000000000(0000) GS:ffff88007d200000(0000) knlGS:ffff88007d200000
2015-08-13T16:39:28.838922+00:00 uk3 kern.warning kernel CS:  e033 DS: 0000 ES: 0000 CR0: 0000000080050033
2015-08-13T16:39:28.838923+00:00 uk3 kern.warning kernel CR2: 0000000000001000 CR3: 00000000771b3000 CR4: 0000000000042660
2015-08-13T16:39:28.838925+00:00 uk3 kern.warning kernel Stack:
2015-08-13T16:39:28.838927+00:00 uk3 kern.warning kernel 00000000000005f0 ffff880077211000 00000000000005f0 ffff8800776bbc70
2015-08-13T16:39:28.838929+00:00 uk3 kern.warning kernel 0000000000000000 ffff88007c74de00 00000000000005f0 ffff880000ed5540
2015-08-13T16:39:28.838931+00:00 uk3 kern.warning kernel ffffffff81838006 000040000000ef70 ffff8800776bbc80 0000000000000000
2015-08-13T16:39:28.838932+00:00 uk3 kern.warning kernel Call Trace:
2015-08-13T16:39:28.838934+00:00 uk3 kern.warning kernel [&lt;ffffffff81838006&gt;] ? tcp_sendmsg+0x3ee/0x9b4
2015-08-13T16:39:28.838936+00:00 uk3 kern.warning kernel [&lt;ffffffff8175c6de&gt;] ? sock_sendmsg+0x2e/0x3b
2015-08-13T16:39:28.838938+00:00 uk3 kern.warning kernel [&lt;ffffffff81666c4a&gt;] ? drbd_send+0xa5/0x171
2015-08-13T16:39:28.838940+00:00 uk3 kern.warning kernel [&lt;ffffffff81666d24&gt;] ? drbd_send_all+0xe/0x23
2015-08-13T16:39:28.838962+00:00 uk3 kern.warning kernel [&lt;ffffffff816682a5&gt;] ? _drbd_no_send_page+0x47/0x5d
2015-08-13T16:39:28.838967+00:00 uk3 kern.warning kernel [&lt;ffffffff8166887d&gt;] ? drbd_send_dblock+0x2e1/0x4ab
2015-08-13T16:39:28.838970+00:00 uk3 kern.warning kernel [&lt;ffffffff811075ae&gt;] ? __wake_up_common+0x47/0x7d
2015-08-13T16:39:28.838973+00:00 uk3 kern.warning kernel [&lt;ffffffff81107a84&gt;] ? __wake_up+0x3a/0x4b
2015-08-13T16:39:28.838975+00:00 uk3 kern.warning kernel [&lt;ffffffff81651643&gt;] ? w_send_dblock+0xd3/0x139
2015-08-13T16:39:28.838978+00:00 uk3 kern.warning kernel [&lt;ffffffff8165279e&gt;] ? drbd_worker+0x124/0x302
2015-08-13T16:39:28.838981+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-08-13T16:39:28.838985+00:00 uk3 kern.warning kernel [&lt;ffffffff81665fa2&gt;] ? drbd_thread_setup+0x47/0x10c
2015-08-13T16:39:28.838999+00:00 uk3 kern.warning kernel [&lt;ffffffff81665f5b&gt;] ? w_complete+0x13/0x13
2015-08-13T16:39:28.839003+00:00 uk3 kern.warning kernel [&lt;ffffffff810f088c&gt;] ? kthread+0xca/0xd2
2015-08-13T16:39:28.839006+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-08-13T16:39:28.839009+00:00 uk3 kern.warning kernel [&lt;ffffffff81962362&gt;] ? ret_from_fork+0x42/0x70
2015-08-13T16:39:28.839012+00:00 uk3 kern.warning kernel [&lt;ffffffff810f07c2&gt;] ? kthread_freezable_should_stop+0x40/0x40
2015-08-13T16:39:28.839016+00:00 uk3 kern.warning kernel Code: eb 2b 4c 39 42 08 4c 89 c0 48 0f 46 42 08 48 85 c0 74 1a 49 01 c1 48 8b 32 48 89 c1 4d 89 ca 49 29 c0 48 89 c3 49 29 c2 4c 89 d7 &lt;f3&gt; a4 48 83 c2 10 4d 85 c0 48 8d 42 f0 75 c8 48 3b 58 08 75 05
2015-08-13T16:39:28.839020+00:00 uk3 kern.alert kernel RIP  [&lt;ffffffff8158ba60&gt;] copy_from_iter+0x140/0x24e
2015-08-13T16:39:28.839031+00:00 uk3 kern.warning kernel RSP &lt;ffff8800776bbb60&gt;
2015-08-13T16:39:28.839035+00:00 uk3 kern.warning kernel CR2: 0000000000001000
2015-08-13T16:39:28.839038+00:00 uk3 kern.warning kernel ---[ end trace edb6ef1729c2cd08 ]---

</pre>
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