INFO: task kworker/u4:2:30 blocked for more than 140 seconds. Not tainted 4.19.0-rc3+ #219 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:2 D15048 30 2 0x80000000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline] _synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667 synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795 synchronize_net+0x3b/0x60 net/core/dev.c:9013 nfnetlink_net_exit_batch+0x10b/0x200 net/netfilter/nfnetlink.c:608 ops_exit_list.isra.7+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551 process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 INFO: task syz-executor3:12268 blocked for more than 140 seconds. Not tainted 4.19.0-rc3+ #219 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25272 12268 5360 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 raw_init+0x2a3/0x330 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x536/0x930 net/socket.c:1275 sock_create net/socket.c:1315 [inline] __sys_socket+0x106/0x260 net/socket.c:1345 __do_sys_socket net/socket.c:1354 [inline] __se_sys_socket net/socket.c:1352 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1352 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572d9 Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b RSP: 002b:00007f967300ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f967300f6d4 RCX: 00000000004572d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c48 R14: 00000000004c9f97 R15: 0000000000000000 INFO: task syz-executor3:12277 blocked for more than 140 seconds. Not tainted 4.19.0-rc3+ #219 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25272 12277 5360 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 raw_init+0x2a3/0x330 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x536/0x930 net/socket.c:1275 sock_create net/socket.c:1315 [inline] __sys_socket+0x106/0x260 net/socket.c:1345 __do_sys_socket net/socket.c:1354 [inline] __se_sys_socket net/socket.c:1352 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1352 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572d9 Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b RSP: 002b:00007f9672fedc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f9672fee6d4 RCX: 00000000004572d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c48 R14: 00000000004c9f97 R15: 0000000000000001 INFO: task syz-executor3:12283 blocked for more than 140 seconds. Not tainted 4.19.0-rc3+ #219 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25400 12283 5360 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 raw_init+0x2a3/0x330 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x536/0x930 net/socket.c:1275 sock_create net/socket.c:1315 [inline] __sys_socket+0x106/0x260 net/socket.c:1345 __do_sys_socket net/socket.c:1354 [inline] __se_sys_socket net/socket.c:1352 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1352 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572d9 Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b RSP: 002b:00007f9672fccc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f9672fcd6d4 RCX: 00000000004572d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c48 R14: 00000000004c9f97 R15: 0000000000000002 INFO: task syz-executor3:12327 blocked for more than 140 seconds. Not tainted 4.19.0-rc3+ #219 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D25272 12327 5360 0x00000004 Call Trace: context_switch kernel/sched/core.c:2825 [inline] __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473 schedule+0xfe/0x460 kernel/sched/core.c:3517 __rwsem_down_write_failed_common+0xbb9/0x1670 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xa5/0x130 kernel/locking/rwsem.c:72 register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 raw_init+0x2a3/0x330 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x536/0x930 net/socket.c:1275 sock_create net/socket.c:1315 [inline] __sys_socket+0x106/0x260 net/socket.c:1345 __do_sys_socket net/socket.c:1354 [inline] __se_sys_socket net/socket.c:1352 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1352 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4572d9 Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4 10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76 75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b RSP: 002b:00007f9672f8ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f9672f8b6d4 RCX: 00000000004572d9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 0000000000930320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d6c48 R14: 00000000004c9f97 R15: 0000000000000004 Showing all locks held in the system: 2 locks held by kworker/1:1/24: #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1b90 kernel/workqueue.c:2124 #1: 000000002b95467a ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9a/0x1b90 kernel/workqueue.c:2128 3 locks held by kworker/u4:2/30: #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000b9edb4fd ((wq_completion)"%s""netns"){+.+.}, at: process_one_work+0xb43/0x1b90 kernel/workqueue.c:2124 #1: 000000005355ac7b (net_cleanup_work){+.+.}, at: process_one_work+0xb9a/0x1b90 kernel/workqueue.c:2128 #2: 000000004c2fc324 (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10 net/core/net_namespace.c:518 1 lock held by khungtaskd/984: #0: 000000000318e4c4 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4436 1 lock held by rsyslogd/5223: #0: 0000000032585ac7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/5313: #0: 00000000e7719689 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000c0b110d2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5314: #0: 00000000c88a30cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d54e9f28 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5315: #0: 00000000814d47cb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000eda76c52 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5316: #0: 00000000e790a1fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000000f5d6aa4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5317: #0: 0000000080144687 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000d3b684e4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5318: #0: 000000007174db53 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 00000000ca8338a3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/5319: #0: 00000000399eb149 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353 #1: 000000003e069785 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by kworker/1:3/5770: #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: 00000000dde524d0 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb43/0x1b90 kernel/workqueue.c:2124 #1: 000000006eacc246 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9a/0x1b90 kernel/workqueue.c:2128 1 lock held by syz-executor3/12268: #0: 000000004c2fc324 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 1 lock held by syz-executor3/12277: #0: 000000004c2fc324 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 1 lock held by syz-executor3/12283: #0: 000000004c2fc324 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 1 lock held by syz-executor3/12327: #0: 000000004c2fc324 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0xbc/0x910 net/core/dev.c:1628 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 984 Comm: khungtaskd Not tainted 4.19.0-rc3+ #219 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+0x1c4/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline] watchdog+0xb3e/0x1050 kernel/hung_task.c:265 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57