unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
INFO: task kworker/0:2:2037 blocked for more than 120 seconds.
Not tainted 4.16.0-rc7+ #3
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:2 D19608 2037 2 0x80000000
Workqueue: events cgwb_release_workfn
Call Trace:
context_switch kernel/sched/core.c:2862 [inline]
__schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
schedule+0xf5/0x430 kernel/sched/core.c:3499
bit_wait+0x18/0x90 kernel/sched/wait_bit.c:250
__wait_on_bit+0x88/0x130 kernel/sched/wait_bit.c:51
out_of_line_wait_on_bit+0x204/0x3a0 kernel/sched/wait_bit.c:64
wait_on_bit include/linux/wait_bit.h:84 [inline]
wb_shutdown+0x335/0x430 mm/backing-dev.c:377
cgwb_release_workfn+0x8b/0x61d mm/backing-dev.c:520
process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113
worker_thread+0x223/0x1990 kernel/workqueue.c:2247
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Showing all locks held in the system:
2 locks held by khungtaskd/867:
#0: (rcu_read_lock){....}, at: [<0000000015008f21>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
#0: (rcu_read_lock){....}, at: [<0000000015008f21>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
#1: (tasklist_lock){.+.+}, at: [<000000002e45031f>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
2 locks held by kworker/0:2/2037:
#0: ((wq_completion)"events"){+.+.}, at: [<00000000b9c30615>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"events"){+.+.}, at: [<00000000b9c30615>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"events"){+.+.}, at: [<00000000b9c30615>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"events"){+.+.}, at: [<00000000b9c30615>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: ((work_completion)(&wb->release_work)){+.+.}, at: [<00000000bf56734c>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
2 locks held by getty/4335:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4336:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4337:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4338:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4339:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4340:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4341:
#0: (&tty->ldisc_sem){++++}, at: [<000000001682fad8>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
#1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000076dc36c>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
3 locks held by kworker/u4:16/14495:
#0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9c30615>] work_static include/linux/workqueue.h:198 [inline]
#0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9c30615>] set_work_data kernel/workqueue.c:619 [inline]
#0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9c30615>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: ((wq_completion)"%s""netns"){+.+.}, at: [<00000000b9c30615>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
#1: (net_cleanup_work){+.+.}, at: [<00000000bf56734c>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
#2: (net_mutex){+.+.}, at: [<000000006e7477a6>] cleanup_net+0x242/0xcb0 net/core/net_namespace.c:484
1 lock held by syz-executor5/22563:
#0: (net_mutex){+.+.}, at: [<00000000864d303f>] copy_net_ns+0x1f5/0x580 net/core/net_namespace.c:417
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 867 Comm: khungtaskd Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x194/0x24d lib/dump_stack.c:53
nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
check_hung_task kernel/hung_task.c:132 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
watchdog+0x90c/0xd60 kernel/hung_task.c:249
kthread+0x33c/0x400 kernel/kthread.c:238
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0-rc7+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x1/0x50 kernel/kcov.c:94
RSP: 0018:ffff8801db2077f8 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 3ffffffffffffffe RCX: 0000000000000020
RDX: ffff8801d9a6ca50 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff8801db207818 R08: 1ffff1003b640e47 R09: dffffc0000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: ffff8801db2079c0 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c421a95000 CR3: 0000000007a22001 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
msecs_to_jiffies include/linux/jiffies.h:367 [inline]
get_sd_balance_interval kernel/sched/fair.c:8756 [inline]
rebalance_domains+0x506/0xcc0 kernel/sched/fair.c:9174
run_rebalance_domains+0x378/0x770 kernel/sched/fair.c:9405
__do_softirq+0x2d7/0xb85 kernel/softirq.c:285
invoke_softirq kernel/softirq.c:365 [inline]
irq_exit+0x1cc/0x200 kernel/softirq.c:405
scheduler_ipi+0x318/0x820 kernel/sched/core.c:1804
smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277
reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:881
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
RSP: 0018:ffffffff87a07c38 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff0f40f8a RCX: 0000000000000000
RDX: 1ffffffff0f59580 RSI: 0000000000000001 RDI: ffffffff87acac00
RBP: ffffffff87a07c38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff87a07cf0 R14: ffffffff883b4a20 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
default_idle+0xbf/0x430 arch/x86/kernel/process.c:354
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345
default_idle_call+0x36/0x90 kernel/sched/idle.c:98
cpuidle_idle_call kernel/sched/idle.c:156 [inline]
do_idle+0x24a/0x3b0 kernel/sched/idle.c:246
cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:351
rest_init+0xed/0xf0 init/main.c:437
start_kernel+0x7f1/0x819 init/main.c:717
x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:378
x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:359
secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:239
Code: 4c 89 e7 e8 c2 46 38 00 e9 32 fd ff ff 48 8b bd d0 fe ff ff e8 51 47 38 00 e9 c3 fc ff ff 90 90 90 90 90 90 90 90 90 90 90 90 55 <65> 48 8b 04 25 c0 ed 01 00 48 89 e5 65 8b 15 1c 24 90 7e 81 e2