INFO: task kworker/u4:0:7 blocked for more than 140 seconds. Not tainted 4.20.0-rc7+ #288 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D14328 7 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline] _synchronize_rcu_expedited.constprop.58+0x882/0x980 kernel/rcu/tree_exp.h:620 synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758 synchronize_net+0x3b/0x60 net/core/dev.c:9074 dev_deactivate_many+0x543/0xdd0 net/sched/sch_generic.c:1222 __dev_close_many+0x197/0x380 net/core/dev.c:1461 dev_close_many+0x2df/0x860 net/core/dev.c:1499 rollback_registered_many+0x543/0x1240 net/core/dev.c:7991 unregister_netdevice_many+0xfa/0x4c0 net/core/dev.c:9119 ip6gre_exit_batch_net+0x5cd/0x7f0 net/ipv6/ip6_gre.c:1594 ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 INFO: task syz-executor2:1860 blocked for more than 140 seconds. Not tainted 4.20.0-rc7+ #288 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D21744 1860 32237 0xa0020006 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 cangw_pernet_exit+0x12/0x30 net/can/gw.c:1005 ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x501/0x8d0 net/core/net_namespace.c:331 copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437 create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x79c/0x10b0 kernel/fork.c:2544 __do_sys_unshare kernel/fork.c:2612 [inline] __se_sys_unshare kernel/fork.c:2610 [inline] __ia32_sys_unshare+0x30/0x40 kernel/fork.c:2610 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7ff5a49 Code: Bad RIP value. RSP: 002b:00000000f5ff10cc EFLAGS: 00000296 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: task syz-executor2:1891 blocked for more than 140 seconds. Not tainted 4.20.0-rc7+ #288 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D23280 1891 32237 0xa0020006 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3472 schedule+0xfe/0x460 kernel/sched/core.c:3516 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 cangw_pernet_exit+0x12/0x30 net/can/gw.c:1005 ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153 setup_net+0x501/0x8d0 net/core/net_namespace.c:331 copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437 create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107 unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206 ksys_unshare+0x79c/0x10b0 kernel/fork.c:2544 __do_sys_unshare kernel/fork.c:2612 [inline] __se_sys_unshare kernel/fork.c:2610 [inline] __ia32_sys_unshare+0x30/0x40 kernel/fork.c:2610 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7ff5a49 Code: Bad RIP value. RSP: 002b:00000000f5faf0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 0000000040000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u4:0/7: #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000cde8d3db ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 000000001e85a7b3 (net_cleanup_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 000000000bf404f8 (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10 net/core/net_namespace.c:518 #3: 00000000f7e2b352 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 3 locks held by kworker/0:1/12: #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000b2761f98 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000c999574e ((addr_chk_work).work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 00000000f7e2b352 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 1 lock held by khungtaskd/1019: #0: 00000000201b6ff2 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379 1 lock held by rsyslogd/5922: #0: 00000000b70ff4c8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/6013: #0: 0000000084550c90 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000005e438215 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6014: #0: 000000004b3872f0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000e8ae57c3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6015: #0: 0000000046ff0b9a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000dcabc3ee (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6016: #0: 00000000638d3ff4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000043ecdc3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6017: #0: 00000000b04c5f3a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003b7d318e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6018: #0: 00000000f135f7ad (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000478cfbd3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 2 locks held by getty/6019: #0: 00000000fbf1fd70 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 0000000047e6dcfd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154 3 locks held by kworker/1:3/21744: #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:218 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000974cdaf5 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124 #1: 00000000b17f7a2b (deferred_process_work){+.+.}, at: process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128 #2: 00000000f7e2b352 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor2/1860: #0: 000000000bf404f8 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0 net/core/net_namespace.c:433 #1: 00000000f7e2b352 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 2 locks held by syz-executor2/1891: #0: 000000000bf404f8 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0 net/core/net_namespace.c:433 #1: 00000000f7e2b352 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1019 Comm: khungtaskd Not tainted 4.20.0-rc7+ #288 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d3/0x2c6 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1c2/0x22c 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb51/0x1060 kernel/hung_task.c:289 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0-rc7+ #288 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.752 msecs Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:match_held_lock+0xa/0x8d0 kernel/locking/lockdep.c:3401 Code: e8 2b 91 61 00 8b 45 84 eb 9d e8 21 91 61 00 e9 57 ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 48 ba 00 00 00 00 00 fc ff df <55> 48 89 e5 41 57 41 56 4c 8d 75 d8 41 55 49 89 fd 48 83 c7 10 41 RSP: 0018:ffff8881dae07320 EFLAGS: 00000002 RAX: 0000000000000000 RBX: fffffbfff128eee7 RCX: 1ffffffff128eee7 RDX: dffffc0000000000 RSI: ffff8881dae2cc98 RDI: ffffffff89477740 RBP: ffff8881dae07370 R08: ffffed103b5c0e5d R09: ffffed103b5c0e5c R10: ffffed103b5c0e5c R11: 0000000000000003 R12: ffffffff89477740 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff89476ec0 FS: 0000000000000000(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001c967a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rq_pin_lock kernel/sched/sched.h:1050 [inline] rq_lock_irqsave kernel/sched/sched.h:1109 [inline] update_blocked_averages+0x1cf/0x1e00 kernel/sched/fair.c:7415 _nohz_idle_balance+0x5ba/0x7a0 kernel/sched/fair.c:9490 nohz_idle_balance kernel/sched/fair.c:9543 [inline] run_rebalance_domains+0x2ec/0x500 kernel/sched/fair.c:9726 __do_softirq+0x30c/0xb2e kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1785 smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:831 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:58 Code: e9 2c ff ff ff 48 89 c7 48 89 45 d8 e8 43 68 ea f9 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 32 68 ea f9 eb 82 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90 RSP: 0018:ffffffff89407c20 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff1280f88 RCX: 0000000000000000 RDX: 1ffffffff12a4031 RSI: 0000000000000001 RDI: ffffffff89520188 RBP: ffffffff89407c20 R08: ffffffff89476ec0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89407ce0 R13: ffffffff8a165c60 R14: 0000000000000000 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:151 [inline] default_idle+0xbf/0x490 arch/x86/kernel/process.c:561 arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:552 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x3db/0x5b0 kernel/sched/idle.c:262 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:353 rest_init+0x243/0x372 init/main.c:443 arch_call_rest_init+0xe/0x1b start_kernel+0x8c2/0x8fd init/main.c:745 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:470 x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243