INFO: task kworker/u4:3:50 blocked for more than 143 seconds.
      Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3    state:D stack:22672 pid:50    tgid:50    ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5400 [inline]
 __schedule+0x17df/0x4a40 kernel/sched/core.c:6727
 __schedule_loop kernel/sched/core.c:6804 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6819
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2159
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 __flush_workqueue+0x730/0x1630 kernel/workqueue.c:3617
 drain_workqueue+0xc9/0x390 kernel/workqueue.c:3730
 destroy_workqueue+0xba/0xc40 kernel/workqueue.c:5319
 bond_destructor+0x4d/0x80 drivers/net/bonding/bond_main.c:5846
 netdev_run_todo+0xd4f/0xf40 net/core/dev.c:10581
 default_device_exit_batch+0x975/0x9f0 net/core/dev.c:11625
 ops_exit_list net/core/net_namespace.c:175 [inline]
 cleanup_net+0x775/0xb90 net/core/net_namespace.c:618
 process_one_work kernel/workqueue.c:3049 [inline]
 process_scheduled_works+0x913/0x14f0 kernel/workqueue.c:3125
 worker_thread+0xa60/0x1000 kernel/workqueue.c:3206
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8e130d60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
3 locks held by kworker/u4:3/50:
 #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888015acd948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc90000ba7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc90000ba7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #2: ffffffff8f36da50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf5/0xb90 net/core/net_namespace.c:580
2 locks held by getty/4828:
 #0: ffff88802a25c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by kworker/1:4/5165:
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc900039cfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc900039cfd20 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #2: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:281
3 locks held by kworker/0:8/5167:
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #0: ffff888014c7cd48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #1: ffffc900039ffd20 (key_gc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3024 [inline]
 #1: ffffc900039ffd20 (key_gc_work){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x14f0 kernel/workqueue.c:3125
 #2: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #2: ffffffff8e1360f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x463/0x820 kernel/rcu/tree_exp.h:939
1 lock held by syz-executor.4/21420:
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:696 [inline]
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3e/0x1b0 drivers/net/tun.c:3504
1 lock held by syz-executor.2/21425:
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:696 [inline]
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3e/0x1b0 drivers/net/tun.c:3504
1 lock held by syz-executor.0/21569:
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x48f/0x2400 drivers/net/tun.c:3114
1 lock held by syz-executor.0/21590:
 #0: ffffffff8f379fc8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x2ce/0x1bc0 net/ipv4/devinet.c:1091

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xfb0/0xff0 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted 6.8.0-rc2-next-20240202-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue:  0x0 (events_unbound)
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:206
Code: 8b 3d 64 d1 1a 0c 48 89 de 5b e9 63 84 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 00 bd 03 00 65 8b 15 70 ec 6f 7e f7 c2 00 01 ff 00
RSP: 0018:ffffc90000107b58 EFLAGS: 00000046
RAX: ffffffff81601268 RBX: 00000000ffffffff RCX: ffff8880172a3c00
RDX: ffff8880172a3c00 RSI: 00000000ffffffff RDI: 00000000ffffffff
RBP: ffff888014c89000 R08: ffffffff81601257 R09: 0000000000000000
R10: ffff888016adb210 R11: ffffed1002d5b645 R12: dffffc0000000000
R13: ffff888014c91000 R14: 0000000000000000 R15: ffff888014c9dc00
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe0d7200000 CR3: 000000007b2b6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 wq_node_nr_active kernel/workqueue.c:1492 [inline]
 pwq_dec_nr_active kernel/workqueue.c:1841 [inline]
 pwq_dec_nr_in_flight+0xf8/0xd60 kernel/workqueue.c:1902
 process_one_work kernel/workqueue.c:3099 [inline]
 process_scheduled_works+0xd43/0x14f0 kernel/workqueue.c:3125
 worker_thread+0xa60/0x1000 kernel/workqueue.c:3206
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:242
 </TASK>