INFO: task kworker/u8:24:18630 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:24   state:D stack:23512 pid:18630 tgid:18630 ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6879
 afs_cell_purge+0x41f/0x4f0 fs/afs/cell.c:893
 afs_net_exit+0x83/0x140 fs/afs/main.c:147
 ops_exit_list net/core/net_namespace.c:200 [inline]
 ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:253
 cleanup_net+0x408/0x890 net/core/net_namespace.c:686
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by getty/5585:
 #0: ffff88814c8bd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900036c62f0
 (
&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
6 locks held by kworker/0:4/5940:
 #0: ffff888143ed7548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90004a07d10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff888029e0e198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #2: ffff888029e0e198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5894
 #3: ffff8880789d3198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #3: ffff8880789d3198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #4: ffff88805d385160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
 #4: ffff88805d385160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
 #5: ffffffff8e478bb0 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214
3 locks held by kworker/u8:23/18629:
 #0: ffff88801b881148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc90004897d10 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff9035e5a8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303
3 locks held by kworker/u8:24/18630:
 #0: ffff88801c6f3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc900048a7d10 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffffffff90348550 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x890 net/core/net_namespace.c:662
3 locks held by kworker/u9:2/22223:
 #0: ffff888058472148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000efd7d10 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff888037208dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x430 net/bluetooth/hci_sync.c:331
2 locks held by syz.4.4879/25474:
 #0: ffffffff9035e5a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline]
 #0: ffffffff9035e5a8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3396
 #1: ffffffff8e5d03f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:304
1 lock held by syz.3.4885/25498:
 #0: ffffffff9035e5a8 (rtnl_mutex){+.+.}-{4:4}, at: bpf_map_offload_map_alloc+0x128/0x7d0 kernel/bpf/offload.c:532
2 locks held by syz.7.4887/25509:
 #0: ffffffff90402dd0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff9035e5a8 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0xb4/0xb10 net/wireless/nl80211.c:16736

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf70/0x12c0 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 9b 6d 02 e9 83 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 b9 23 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6
RAX: 000000000742bbe1 RBX: 0000000000000001 RCX: ffffffff8b865c99
RDX: 0000000000000000 RSI: ffffffff8de2f481 RDI: ffffffff8c157260
RBP: ffffed1003c5c488 R08: 0000000000000001 R09: ffffed10170a6645
R10: ffff8880b853322b R11: 0000000000000001 R12: 0000000000000001
R13: ffff88801e2e2440 R14: ffffffff90a93850 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888124822000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004c00 CR3: 0000000049b80000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>