syzbot

INFO: task kworker/0:0:18190 blocked for more than 120 seconds.
      Not tainted 4.4.131-gaa3863d #41
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:0     D ffff8800ab3dfaf8 28432 18190      2 0x00000000
Workqueue: ipv6_addrconf addrconf_verify_work
 ffff8800ab3dfaf8 0000000000000002 ffff8801d7eca0e0 ffffed003afd941b
 ffff8801d7ec9800 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8
 ffff8801db21f4c0 ffffffff84417840 ffff8801d7ec9800 0000000000000000
Call Trace:
 [<ffffffff838b1e4a>] schedule+0x7a/0x1b0 kernel/sched/core.c:3359
 [<ffffffff838b25e3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392
 [<ffffffff838b8727>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838b8727>] mutex_lock_nested+0x307/0x850 kernel/locking/mutex.c:621
 [<ffffffff82fb10c7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff83450e1e>] addrconf_verify_work+0xe/0x20 net/ipv6/addrconf.c:4110
 [<ffffffff81181d5f>] process_one_work+0x7df/0x1600 kernel/workqueue.c:2064
 [<ffffffff81182c59>] worker_thread+0xd9/0xfc0 kernel/workqueue.c:2196
 [<ffffffff81190768>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c0295>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
3 locks held by kworker/0:0/18190:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81181c40>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81181c40>] set_work_data kernel/workqueue.c:625 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81181c40>] set_work_pool_and_clear_pending kernel/workqueue.c:652 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81181c40>] process_one_work+0x6c0/0x1600 kernel/workqueue.c:2057
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81181c7a>] process_one_work+0x6fa/0x1600 kernel/workqueue.c:2061
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff82fb10c7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.131-gaa3863d #41
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffffffff84417840 task.stack: ffffffff84400000
RIP: 0010:[<ffffffff812362b1>]  [<ffffffff812362b1>] __lock_release kernel/locking/lockdep.c:3408 [inline]
RIP: 0010:[<ffffffff812362b1>]  [<ffffffff812362b1>] lock_release+0x761/0xc30 kernel/locking/lockdep.c:3611
RSP: 0018:ffffffff84407d20  EFLAGS: 00000086
RAX: 00000000ffffffff RBX: ffffffff844bdc20 RCX: 1ffffffff0942910
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8441811c
RBP: ffffffff84407dd0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff84417840 R12: 0000000000000002
R13: 1ffffffff074890c R14: fffffbfff074890c R15: ffffffff84a14e78
FS:  0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000850000 CR3: 00000001cacdb000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 fffffbfff074890c ffffffff84417840 0000000000000000 0000000000000000
 0000000000000002 0000000000000000 ffffffff84407dd0 0000000000000000
 ffffffff84407da0 ffffffff81e6db1b ffffffff84407dd0 0000000000000000
Call Trace:
 [<ffffffff811955cf>] rcu_lock_release include/linux/rcupdate.h:482 [inline]
 [<ffffffff811955cf>] rcu_read_unlock include/linux/rcupdate.h:917 [inline]
 [<ffffffff811955cf>] __atomic_notifier_call_chain kernel/notifier.c:184 [inline]
 [<ffffffff811955cf>] atomic_notifier_call_chain+0xbf/0x140 kernel/notifier.c:193
 [<ffffffff8113047e>] idle_notifier_call_chain+0x1e/0x30 kernel/cpu.c:865
 [<ffffffff8102728f>] __exit_idle arch/x86/kernel/process.c:247 [inline]
 [<ffffffff8102728f>] arch_cpu_idle_exit+0x1f/0x30 arch/x86/kernel/process.c:268
 [<ffffffff8121bd49>] cpu_idle_loop kernel/sched/idle.c:255 [inline]
 [<ffffffff8121bd49>] cpu_startup_entry+0x269/0x780 kernel/sched/idle.c:301
 [<ffffffff838acfb1>] rest_init+0x188/0x18e init/main.c:410
 [<ffffffff84a4b8a1>] start_kernel+0x6b3/0x6e7 init/main.c:682
 [<ffffffff84a4a30f>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff84a4a450>] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:185
Code: c2 e0 5c a5 83 be 3d 0d 00 00 48 c7 c7 20 5d a5 83 e8 94 9b ef ff 48 8b 55 c0 48 89 de 48 8b 7d d0 e8 24 5b ff ff e9 24 ff ff ff <65> ff 05 d8 03 de 7e 48 8b 05 01 ed 7c 03 e8 2c 0f 04 00 85 c0 
NMI backtrace for cpu 1
CPU: 1 PID: 491 Comm: khungtaskd Not tainted 4.4.131-gaa3863d #41
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8800bb18b000 task.stack: ffff8800bb130000
RIP: 0010:[<ffffffff810bfda6>]  [<ffffffff810bfda6>] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline]
RIP: 0010:[<ffffffff810bfda6>]  [<ffffffff810bfda6>] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline]
RIP: 0010:[<ffffffff810bfda6>]  [<ffffffff810bfda6>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline]
RIP: 0010:[<ffffffff810bfda6>]  [<ffffffff810bfda6>] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800bb137cc8  EFLAGS: 00000046
RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300
RBP: ffff8800bb137cf0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f7a0
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f89fc3d0000 CR3: 00000001cbd18000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff8446f7a0 ffffffff84a18a20 0000000000000007 fffffbfff0942bf4
 0000000000000040 ffff8800bb137d10 ffffffff810b5d61 ffffffff83c0b1a0
 0000000000000003 ffff8800bb137d68 ffffffff81e19003 ffffffff8140d96f
Call Trace:
 [<ffffffff810b5d61>] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81e19003>] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85
 [<ffffffff810b5e04>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff8141a059>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff8141a059>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8141a059>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8141a059>] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff81190768>] kthread+0x268/0x300 kernel/kthread.c:211
 [<ffffffff838c0295>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510
Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 62