INFO: task kworker/u8:0:11 blocked for more than 143 seconds.
      Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0    state:D
 stack:20560 pid:11    tgid:11    ppid:2      flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5192 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414
 ops_pre_exit_list net/core/net_namespace.c:163 [inline]
 cleanup_net+0x615/0xcc0 net/core/net_namespace.c:620
 process_one_work kernel/workqueue.c:3248 [inline]
 process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3329
 worker_thread+0x86d/0xd50 kernel/workqueue.c:3409
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/11:
 #0: ffff888015ed5948
 (
(wq_completion)netns){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3223 [inline]
, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: 
ffffc90000107d00
 (
net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3224 [inline]
, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: 
ffffffff8f5e2c90
 (
pernet_ops_rwsem
){++++}-{3:3}
, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:594
 #3: ffffffff8f5ef4c8
 (rtnl_mutex
){+.+.}-{3:3}
, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:414
1 lock held by khungtaskd/30:
 #0: ffffffff8e3354a0
 (
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6689
3 locks held by kworker/u8:4/62:
 #0: ffff88802a223148 ((wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3223 [inline]
, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: 
ffffc900015dfd00
 (
(work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3224 [inline]
, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: 
ffffffff8f5ef4c8
 (rtnl_mutex
){+.+.}-{3:3}
, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4733
3 locks held by kworker/1:2/784:
 #0: ffff888015080948
 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3223 [inline]
 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3329
 #1: 
ffffc900035cfd00 (
deferred_process_work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3224 [inline]
, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3329
 #2: ffffffff8f5ef4c8
 (
rtnl_mutex){+.+.}-{3:3}
, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by getty/4847:
 #0: 
ffff88802ac0f0a0
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0
 (&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
1 lock held by syz-executor.2/7816:
 #0: ffffffff8f5ef4c8
 (
rtnl_mutex){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
8 locks held by syz-executor.3/7818:
1 lock held by syz-executor.4/7831:
 #0: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
2 locks held by syz-executor.0/7843:
 #0: 
ffffffff8ee49ba8
 (ppp_mutex
){+.+.}-{3:3}
, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:714
 #1: ffffffff8f5ef4c8
 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3331 [inline]
 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1045 [inline]
 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x78b/0x1cd0 drivers/net/ppp/ppp_generic.c:718
1 lock held by syz-executor.0/7844:
 #0: 
ffffffff8ee49ba8
 (
ppp_mutex
){+.+.}-{3:3}
, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:714
1 lock held by syz-executor.0/7847:
 #0: 
ffffffff8ee49ba8
 (
ppp_mutex
){+.+.}-{3:3}
, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:714
1 lock held by syz-executor.3/7917:
 #0: 
ffffffff8f5ef4c8
 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.2/7918:
 #0: 
ffffffff8f5ef4c8 (
rtnl_mutex
){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.0/7929:
 #0: ffffffff8f5ef4c8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.1/7934:
 #0: 
ffffffff8f5ef4c8
 (
rtnl_mutex){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.4/7936:
 #0: ffffffff8f5ef4c8
 (rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.1/7939:
 #0: 
ffffffff8f5ef4c8
 (
rtnl_mutex){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.2/7943:
 #0: 
ffffffff8f5ef4c8
 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.0/7946:
 #0: 
ffffffff8f5ef4c8 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.3/7948:
 #0: 
ffffffff8f5ef4c8
 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.4/7956:
 #0: 
ffffffff8f5ef4c8
 (rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724
1 lock held by syz-executor.1/7959:
 #0: 
ffffffff8f5ef4c8 (
rtnl_mutex
){+.+.}-{3:3}
, at: rtnetlink_rcv_msg+0x839/0x1170 net/core/rtnetlink.c:6724

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

NMI backtrace for cpu 1
CPU: 1 PID: 30 Comm: khungtaskd Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:91 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:117
 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:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:144
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7818 Comm: syz-executor.3 Not tainted 6.10.0-rc3-next-20240611-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:io_serial_in+0x76/0xb0 drivers/tty/serial/8250/8250_port.c:406
Code: 60 c8 54 fc 89 e9 41 d3 e6 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 11 d7 ba fc 44 03 33 44 89 f2 ec <0f> b6 c0 5b 41 5e 41 5f 5d c3 cc cc cc cc 89 e9 80 e1 07 38 c1 7c
RSP: 0018:ffffc90000007298 EFLAGS: 00000002
RAX: 1ffffffff295e400 RBX: ffffffff94af23a0 RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000000 R08: ffffffff853e7f86 R09: 1ffff11003ec0046
R10: dffffc0000000000 R11: ffffffff853e7f40 R12: dffffc0000000000
R13: ffffffff94803bb0 R14: 00000000000003fd R15: dffffc0000000000
FS:  00007f4ce3a906c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f138eee5000 CR3: 00000000788ca000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 serial_in drivers/tty/serial/8250/8250.h:137 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
 wait_for_lsr drivers/tty/serial/8250/8250_port.c:2068 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3315 [inline]
 serial8250_console_write+0x1373/0x1ed0 drivers/tty/serial/8250/8250_port.c:3393
 console_emit_next_record kernel/printk/printk.c:2975 [inline]
 console_flush_all+0x880/0xf50 kernel/printk/printk.c:3047
 console_unlock+0x13b/0x4d0 kernel/printk/printk.c:3118
 vprintk_emit+0x7a1/0x900 kernel/printk/printk.c:2420
 _printk+0xd5/0x120 kernel/printk/printk.c:2447
 printk_stack_address arch/x86/kernel/dumpstack.c:72 [inline]
 show_trace_log_lvl+0x43a/0x520 arch/x86/kernel/dumpstack.c:285
 sched_show_task+0x578/0x740 kernel/sched/core.c:7432
 report_rtnl_holders+0x1ba/0x2d0 net/core/rtnetlink.c:104
 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1792
 expire_timers kernel/time/timer.c:1843 [inline]
 __run_timers kernel/time/timer.c:2417 [inline]
 __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428
 run_timer_base kernel/time/timer.c:2437 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:get_current arch/x86/include/asm/current.h:49 [inline]
RIP: 0010:debug_lockdep_rcu_enabled+0x18/0x40 kernel/rcu/update.c:321
Code: 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 67 55 23 04 00 74 1e 83 3d d6 86 23 04 00 74 15 <65> 48 8b 0c 25 00 d6 03 00 31 c0 83 b9 dc 0a 00 00 00 0f 94 c0 c3
RSP: 0018:ffffc90004bf66f8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000001 RCX: f576c19a971dad00
RDX: dffffc0000000000 RSI: ffffffff8bcad320 RDI: ffffffff8c200760
RBP: ffffc90004bf67d0 R08: ffffffff92fcb747 R09: 1ffffffff25f96e8
R10: dffffc0000000000 R11: fffffbfff25f96e9 R12: dffffc0000000000
R13: ffffffff897eab60 R14: ffff88807cbf7e90 R15: dffffc0000000000
 rcu_read_lock include/linux/rcupdate.h:839 [inline]
 tcf_idr_check_alloc+0x136/0x900 net/sched/act_api.c:834
 tcf_police_init+0x29b/0x17c0 net/sched/act_police.c:75
 tcf_action_init_1+0x5d7/0x890 net/sched/act_api.c:1426
 tcf_action_init+0x2e4/0x940 net/sched/act_api.c:1489
 tcf_action_add net/sched/act_api.c:2062 [inline]
 tc_ctl_action+0x47d/0xcf0 net/sched/act_api.c:2119
 rtnetlink_rcv_msg+0x892/0x1170 net/core/rtnetlink.c:6727
 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585
 ___sys_sendmsg net/socket.c:2639 [inline]
 __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2668
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4ce2c7cea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4ce3a900c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4ce2db3f80 RCX: 00007f4ce2c7cea9
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000006
RBP: 00007f4ce2cebff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f4ce2db3f80 R15: 00007fffa40358e8
 </TASK>