Public bug reported:
Running in Virtualbox as a guest in a Macbook Pro, I'm running into a
reliably-reproducible kernel oops on Ubuntu 16.04 with Linux
4.4.0-17-generic.
The stack trace isn't always the same, although the error always happens
in the same `update_blocked_averages` function.
Here' one oops:
```
[ 56.972407] BUG: unable to handle kernel NULL pointer dereference at
0910
[ 57.076894] IP: [] update_blocked_averages+0x8d/0x520
[ 57.173751] PGD 0
[ 57.193537] Oops: [#1] SMP
[ 57.245472] Modules linked in: veth xt_addrtype xt_conntrack ipt_MASQUERADE
nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
iptable_filter ip_tables x_tables nf_nat nf_conntrack bridge stp llc aufs ppdev
crct10dif_pclmul crc32_pclmul snd_intel8x0 snd_ac97_codec aesni_intel ac97_bus
aes_x86_64 snd_pcm lrw gf128mul snd_timer input_leds glue_helper ablk_helper
snd cryptd joydev serio_raw soundcore i2c_piix4 8250_fintek mac_hid parport_pc
lp parport autofs4 hid_generic usbhid ahci psmouse hid libahci pata_acpi e1000
video fjes
[ 57.937239] CPU: 1 PID: 269 Comm: systemd-journal Not tainted
4.4.0-17-generic #33-Ubuntu
[ 58.049743] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
VirtualBox 12/01/2006
[ 58.189828] task: 8800d8f90dc0 ti: 8800da9a8000 task.ti:
8800da9a8000
[ 58.299087] RIP: 0010:[] []
update_blocked_averages+0x8d/0x520
[ 58.320327] RSP: 0018:8800da9abc70 EFLAGS: 00010046
[ 58.366603] RAX: RBX: 88020c3bae00 RCX:
[ 58.514856] RDX: RSI: RDI: 0001
[ 58.612464] RBP: 8800da9abcc8 R08: afb504000afb5041 R09:
[ 58.738629] R10: 0002 R11: R12: 0045
[ 58.885338] R13: R14: 8802198975c0 R15: 0001
[ 59.001563] FS: 7f7db7f6e840() GS:88021988()
knlGS:
[ 59.160653] CS: 0010 DS: ES: CR0: 80050033
[ 59.296218] CR2: 0910 CR3: 00020c3fd000 CR4: 000406e0
[ 59.418514] Stack:
[ 59.458306] 000205f5 880219896d00 0086
afb504000afb5041
[ 59.580604] ad6001fe 0001
02f8
[ 59.720268] 00016d00 880219896d00 8800d8f91310
8800da9abd38
[ 59.848040] Call Trace:
[ 59.902635] [] pick_next_task_fair+0x1e7/0x4f0
[ 59.992238] [] __schedule+0x125/0xa10
[ 60.030794] [] schedule+0x35/0x80
[ 60.074193] [] schedule_hrtimeout_range_clock+0x193/0x1b0
[ 60.134427] [] ? ep_scan_ready_list+0x1e7/0x1f0
[ 60.195234] [] ?
__raw_callee_save___pv_queued_spin_unlock+0x11/0x20
[ 60.289354] [] schedule_hrtimeout_range+0x13/0x20
[ 60.325540] [] ep_poll+0x2c0/0x3d0
[ 60.328490] [] ? wake_up_q+0x70/0x70
[ 60.387888] [] SyS_epoll_wait+0xb8/0xd0
[ 60.502960] [] entry_SYSCALL_64_fastpath+0x16/0x71
[ 60.610213] Code: 24 08 49 b8 41 50 fb 0a 00 04 b5 af 4d 89 fe 0f 1f 44 00
00 44 8b 9b 24 01 00 00 45 85 db 0f 85 a0 03 00 00 48 8b 83 c8 00 00 00 <48> 8b
80 10 09 00 00 48 2b 83 18 01 00 00 48 8b 93 a0 00 00 00
[ 60.941287] RIP [] update_blocked_averages+0x8d/0x520
[ 61.111617] RSP
[ 61.201406] CR2: 0910
[ 61.258351] ---[ end trace fe3df8ee7b476828 ]---
```
Here's another one:
```
[ 154.454951] BUG: unable to handle kernel [ 154.455154] device vethe5e9554
entered promiscuous mode
[ 154.455202] IPv6: ADDRCONF(NETDEV_UP): vethe5e9554: link is not ready
[ 154.455203] docker0: port 1(vethe5e9554) entered forwarding state
[ 154.455210] docker0: port 1(vethe5e9554) entered forwarding state
[ 154.744305] NULL pointer dereference at 0910
[ 154.783574] IP: [] update_blocked_averages+0x8d/0x520
[ 154.784877] PGD 0
[ 154.785372] Oops: [#1] SMP
[ 154.790654] Modules linked in: veth xt_addrtype xt_conntrack ipt_MASQUERADE
nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4
iptable_filter ip_tables x_tables nf_nat nf_conntrack bridge stp llc aufs
vboxsf(OE) ppdev crct10dif_pclmul crc32_pclmul aesni_intel snd_intel8x0
aes_x86_64 input_leds lrw snd_ac97_codec gf128mul glue_helper ac97_bus
ablk_helper cryptd serio_raw vboxvideo(OE) joydev snd_pcm i2c_piix4 snd_timer
drm 8250_fintek snd soundcore vboxguest(OE) parport_pc mac_hid lp parport
autofs4 hid_generic usbhid ahci hid psmouse libahci e1000 pata_acpi video fjes
[ 155.387419] CPU: 0 PID: 2043 Comm: systemd-udevd Tainted: G OE
4.4.0-17-generic #33-Ubuntu
[ 155.546119] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS
VirtualBox 12/01/2006
[ 155.654775] task: 8800dbb3b700 ti: 88020da8c000 task.ti:
88020da8c000
[ 155.753906] RIP: 0010:[] []
update_blocked_averages+0x8d/0x520
[ 155.775805] RSP: :880219803df0 EFLAGS: 00010046
[ 155.811224] RAX: RBX: 8800db891200 RCX:
