INFO: task kworker/u4:0:30712 blocked for more than 143 seconds. Not tainted 5.4.0-rc2+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D24680 30712 2 0x80004000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:3384 [inline] __schedule+0x74b/0xb80 kernel/sched/core.c:4069 schedule+0x131/0x1e0 kernel/sched/core.c:4136 rxrpc_destroy_all_calls+0x16a/0x530 net/rxrpc/call_object.c:631 rxrpc_exit_net+0x61/0xb0 net/rxrpc/net_ns.c:121 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x69a/0xaa0 net/core/net_namespace.c:594 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 1 lock held by khungtaskd/1064: #0: ffffffff888d3ec0 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by rsyslogd/7886: #0: ffff88809b8dd3e0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x243/0x2e0 fs/file.c:801 2 locks held by getty/7976: #0: ffff88809a2b5090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7977: #0: ffff8880a7b4c090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f1d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7978: #0: ffff8880a7558090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7979: #0: ffff8880a79f9090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7980: #0: ffff88809fbb6090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7981: #0: ffff8880915e9090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f432e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 2 locks held by getty/7982: #0: ffff8880a208f090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:272 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x221/0x1b00 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:0/30712: #0: ffff88821b6bb928 ((wq_completion)netns){+.+.}, at: spin_unlock_irq include/linux/spinlock.h:388 [inline] #0: ffff88821b6bb928 ((wq_completion)netns){+.+.}, at: process_one_work+0x75d/0x10e0 kernel/workqueue.c:2242 #1: ffff88802c747d78 (net_cleanup_work){+.+.}, at: process_one_work+0x79f/0x10e0 kernel/workqueue.c:2244 #2: ffffffff88b00a68 (pernet_ops_rwsem){++++}, at: cleanup_net+0xa5/0xaa0 net/core/net_namespace.c:556 3 locks held by kworker/u4:4/25577: #0: ffff8880aea34998 (&rq->lock){-.-.}, at: newidle_balance+0x629/0xb60 kernel/sched/fair.c:9817 #1: ffffffff888d3ec0 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 #2: ffff8880aea24a98 (&base->lock){-.-.}, at: lock_timer_base kernel/time/timer.c:936 [inline] #2: ffff8880aea24a98 (&base->lock){-.-.}, at: __mod_timer+0x1a1/0x1590 kernel/time/timer.c:1008 1 lock held by syz-executor.4/8543: #0: ffffffff88b00a68 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x32/0x5f0 net/core/dev.c:1644 1 lock held by syz-executor.4/8547: #0: ffffffff88b00a68 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x32/0x5f0 net/core/dev.c:1644 1 lock held by syz-executor.4/8551: #0: ffffffff88b00a68 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x32/0x5f0 net/core/dev.c:1644 1 lock held by syz-executor.4/8580: #0: ffffffff88b00a68 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x32/0x5f0 net/core/dev.c:1644 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1064 Comm: khungtaskd Not tainted 5.4.0-rc2+ #0 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+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xbb9/0xbd0 kernel/hung_task.c:289 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 25577 Comm: kworker/u4:4 Not tainted 5.4.0-rc2+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__sanitizer_cov_trace_pc+0x48/0x50 kernel/kcov.c:112 Code: f8 12 00 00 83 fa 02 75 21 48 8b 91 00 13 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 12 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a 0f 1f 80 00 00 00 00 4c 8b 04 24 65 48 8b 04 25 c0 fd 01 00 65 RSP: 0018:ffff8880610b7c60 EFLAGS: 00000293 RAX: ffffffff87546d8e RBX: ffff8880a7bcdec0 RCX: ffff8880630c8340 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff888d3ec0 RBP: ffff8880610b7c68 R08: dffffc0000000000 R09: ffffed1015d46b05 R10: ffffed1015d46b05 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff888067e80000 R14: ffff888067e78b40 R15: 0000000000000010 FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000a5792000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:653 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x281/0x600 net/batman-adv/network-coding.c:718 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352