Comment 11 for bug 1592597

We look to have had a hard recurrance of this issue on the system. After much messing about we appear to have gotten some real stack traces. We see similar ones on a range of kernel versions in 3.13.0-* series:

NULL pointer dereference at 0000000000000010
[ 15.316900] IP: [<ffffffff813700a1>] rb_next+0x1/0x50
[ 15.316910] PGD 0
[ 15.316913] Oops: 0000 [#1] SMP
[ 15.316917] Modules linked in: btrfs xor raid6_pq libcrc32c hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ixgbe igb aesni_intel aes_x86_64 lrw dca gf128mul glue_helper ablk_helper ptp cryptd ahci pps_core i2c_algo_bit libahci mdi
o megaraid_sas wmi
[ 15.316940] CPU: 13 PID: 883 Comm: upstart-udev-br Not tainted 3.13.0-88-generic #135-Ubuntu
[ 15.316942] Hardware name: Dell Inc. PowerEdge R630/0CNCJW, BIOS 1.0.4 08/28/2014
[ 15.316943] task: ffff883fcd8d1800 ti: ffff883fcd870000 task.ti: ffff883fcd870000
[ 15.316947] RIP: 0010:[<ffffffff813700a1>] [<ffffffff813700a1>] rb_next+0x1/0x50
[ 15.316948] RSP: 0018:ffff883fcd871870 EFLAGS: 00010046
[ 15.316950] RAX: 0000000000000000 RBX: ffff883fd063f600 RCX: 0000000000000000
[ 15.316951] RDX: ffff883ffecd3180 RSI: ffff883ffecd3228 RDI: 0000000000000010
[ 15.316952] RBP: ffff883fcd8718b8 R08: 0000000000000000 R09: 0000000000000001
[ 15.316953] R10: 0000000000000001 R11: 0000000000000304 R12: 0000000000000000
[ 15.316954] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 15.316956] FS: 00007f63bc298740(0000) GS:ffff883ffecc0000(0000) knlGS:0000000000000000
[ 15.316957] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 15.316958] CR2: 0000000000000010 CR3: 0000003fd0604000 CR4: 00000000001407e0
[ 15.316959] Stack:
[ 15.316965] ffff883fcd8718b8 ffffffff810a2c72 0000000dcd8718a8 ffff883ffecd3180
[ 15.316970] ffff883fcd8d1c28 ffff883ffecd3180 000000000000000d 0000000000000007
[ 15.316974] 0000000000000007 ffff883fcd871918 ffffffff8172d712 ffff883fcd8d1800
[ 15.316975] Call Trace:
[ 15.316986] [<ffffffff810a2c72>] ? pick_next_task_fair+0x102/0x1b0
[ 15.316994] [<ffffffff8172d712>] __schedule+0x142/0x7f0
[ 15.316997] [<ffffffff8172dde9>] schedule+0x29/0x70
[ 15.317001] [<ffffffff8172d42d>] schedule_hrtimeout_range_clock+0x14d/0x170
[ 15.317007] [<ffffffff811d50df>] ? __pollwait+0x7f/0xf0
[ 15.317014] [<ffffffff8173190b>] ? _raw_spin_unlock_bh+0x1b/0x40
[ 15.317019] [<ffffffff81657cce>] ? netlink_poll+0x13e/0x1e0
[ 15.317022] [<ffffffff8172d463>] schedule_hrtimeout_range+0x13/0x20
[ 15.317026] [<ffffffff811d5199>] poll_schedule_timeout+0x49/0x70
[ 15.317029] [<ffffffff811d5b86>] do_select+0x5b6/0x780
[ 15.317037] [<ffffffff811a54ad>] ? kfree+0x11d/0x160
[ 15.317041] [<ffffffff811d5320>] ? poll_select_copy_remaining+0x130/0x130
[ 15.317044] [<ffffffff811d5320>] ? poll_select_copy_remaining+0x130/0x130
[ 15.317047] [<ffffffff811d5320>] ? poll_select_copy_remaining+0x130/0x130
[ 15.317055] [<ffffffff8115bac3>] ? __alloc_pages_nodemask+0x1a3/0xb90
[ 15.317061] [<ffffffff8161402a>] ? sock_recvmsg+0x9a/0xd0
[ 15.317070] [<ffffffff811524f3>] ? unlock_page+0x23/0x30
[ 15.317078] [<ffffffff811794b9>] ? __do_fault+0x429/0x530
[ 15.317082] [<ffffffff811d5f1c>] core_sys_select+0x1cc/0x2e0
[ 15.317089] [<ffffffff810ad5cd>] ? remove_wait_queue+0x4d/0x60
[ 15.317096] [<ffffffff8106b743>] ? do_wait+0x123/0x250
[ 15.317100] [<ffffffff811d60db>] SyS_select+0xab/0x100
[ 15.317103] [<ffffffff8106a410>] ? task_stopped_code+0x60/0x60
[ 15.317109] [<ffffffff8173a4dd>] system_call_fastpath+0x1a/0x1f
[ 15.317130] Code: e5 48 85 c0 75 07 eb 19 66 90 48 89 d0 48 8b 50 10 48 85 d2 75 f4 48 8b 50 08 48 85 d2 75 eb 5d c3 31 c0 5d c3 0f 1f 44 00 00 55 <48> 8b 17 48 89 e5 48 39 d7 74 3b 48 8b 47 08 48 85 c0 75 0e eb
[ 15.317133] RIP [<ffffffff813700a1>] rb_next+0x1/0x50
[ 15.317133] RSP <ffff883fcd871870>
[ 15.317134] CR2: 0000000000000010
[ 15.317137] ---[ end trace 91af0079725c7159 ]---