INFO: task kworker/u8:8:7218 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:8    state:D stack:22240 pid:7218  tgid:7218  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908
 __schedule_loop kernel/sched/core.c:6990 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7005
 afs_cell_purge+0x40d/0x580 fs/afs/cell.c:921
 afs_net_exit+0x50/0x100 fs/afs/main.c:147
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
 cleanup_net+0x56b/0x800 net/core/net_namespace.c:704
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 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 ksoftirqd/0/15:
 #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
1 lock held by khungtaskd/30:
 #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/58:
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc900015f7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc900015f7c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffffffff8fbccd88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by udevd/5191:
2 locks held by getty/5580:
 #0: ffff8880374380a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:8/7218:
 #0: ffff88801b6de948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88801b6de948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc9000213fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc9000213fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffffffff8fbbe5f0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675
4 locks held by kworker/0:3/17184:
 #0: ffff88802168ed48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88802168ed48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90004cb7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90004cb7c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffff88802aa0f198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff88802aa0f198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
 #3: ffff8880528d1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff8880528d1198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1008
2 locks held by syz.2.3894/19230:
 #0: ffffffff8fbccd88 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8fbccd88 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
 #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 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: 5191 Comm: udevd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:check_preemption_disabled+0x6/0xe0 lib/smp_processor_id.c:14
Code: c7 c6 e0 b3 27 8c eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 <65> 8b 05 57 d3 6d 07 65 8b 0d 4c d3 6d 07 f7 c1 ff ff ff 7f 74 0c
RSP: 0018:ffffc90004637950 EFLAGS: 00000283
RAX: 0000000000000001 RBX: 00007fc948915937 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c27b3e0 RDI: ffffffff8c27b3a0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90004637af8 R11: ffffffff81b0bfa0 R12: 0000000000000002
R13: ffffffff8e75e420 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fc948f69880(0000) GS:ffff888125563000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9a57eb4b8 CR3: 000000007ca60000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
 rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x57/0x2e0 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 is_bpf_text_address+0x47/0x2b0 kernel/bpf/core.c:748
 kernel_text_address+0xa5/0xe0 kernel/extable.c:125
 __kernel_text_address+0xd/0x30 kernel/extable.c:79
 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
 arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2692 [inline]
 slab_free mm/slub.c:6168 [inline]
 kmem_cache_free+0x187/0x630 mm/slub.c:6298
 free_filename fs/namei.c:147 [inline]
 putname fs/namei.c:306 [inline]
 class_filename_destructor include/linux/fs.h:2539 [inline]
 __do_sys_unlink fs/namei.c:5576 [inline]
 __se_sys_unlink+0xc2/0x140 fs/namei.c:5572
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc948915937
Code: 00 00 e9 a9 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 5f 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 91 b4 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffda676b058 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fc948915937
RDX: 0000000000000000 RSI: 00000000457fbf80 RDI: 0000558b1c46702e
RBP: 0000000000000000 R08: 00000000458978be R09: 3fffffffffffffff
R10: 4000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000558b1c482100 R14: 0000000000000001 R15: 0000000000000000
 </TASK>