INFO: task syz-executor0:11169 blocked for more than 140 seconds.
      Not tainted 4.9.111-g03c70fe #58
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29112 11169   3853 0x00000004
 ffff8801a4c4e000 0000000000000000 ffff8801d00ac540 ffffffff84629800
 ffff8801db221c18 ffff8801ccce7a38 ffffffff839e7ded ffff8801a4c4e8c8
 ffffed0034989d18 ffff8801a4c4e000 00fffc0000000000 ffff8801db2224e8
Call Trace:
 [<ffffffff839e93ef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839e9d73>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3590
 [<ffffffff839ee1f6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff839ee1f6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff830d9b36>] dev_ioctl+0x856/0xdb0 net/core/dev_ioctl.c:406
 [<ffffffff83010119>] sock_do_ioctl+0x99/0xb0 net/socket.c:899
 [<ffffffff83010ba6>] sock_ioctl+0x346/0x3e0 net/socket.c:978
 [<ffffffff815b2c6c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b2c6c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b2c6c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b3cef>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b3cef>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f8cd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813666fc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813666fc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425d87>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
3 locks held by kworker/0:3/1839:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d03e>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d03e>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d03e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff8118d03e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff8118d078>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by rsyslogd/3686:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d810c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3782:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f6e92>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211e602>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/11169:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor2/11171:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/11177:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor3/11207:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11182:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11208:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11210:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11218:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11219:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor5/11220:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/11190:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/11211:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor6/11213:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/11196:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor4/11222:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by syz-executor7/11230:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff830b4937>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.111-g03c70fe #58
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d9647d08 ffffffff81eb2729 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9af0 ffff8801d9647d40
 ffffffff81ebda27 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb2729>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb2729>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebda27>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebd9ba>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9bf4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366c94>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366c94>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366c94>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366c94>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d05d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f8e9c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff839f78f6