INFO: task kworker/u8:10:3540 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:10 state:D stack:23544 pid:3540 tgid:3540 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 afs_cell_purge+0x41f/0x4f0 fs/afs/cell.c:894 afs_net_exit+0x83/0x140 fs/afs/main.c:147 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252 cleanup_net+0x41b/0x8b0 net/core/net_namespace.c:695 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:10/3540: #0: ffff88801ba94948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000cf47d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900d0430 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x8b0 net/core/net_namespace.c:669 3 locks held by acpid/5172: #0: ffff888087e30160 (&joydev->mutex){+.+.}-{4:4}, at: joydev_open_device drivers/input/joydev.c:200 [inline] #0: ffff888087e30160 (&joydev->mutex){+.+.}-{4:4}, at: joydev_open+0x222/0x850 drivers/input/joydev.c:272 #1: ffff888046ddf2c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:230 [inline] #1: ffff888046ddf2c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_open_device+0x4b/0x3d0 drivers/input/input.c:583 #2: ffffffff8e3cf9f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 2 locks held by getty/5577: #0: ffff88814e4170a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 2 locks held by kworker/1:7/5934: #0: ffff88813ff11948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90002f17d00 ((work_completion)(&fw_work->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 6 locks held by kworker/1:9/31224: #0: ffff8880236b8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90004637d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff8881453ae198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 #3: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline] #3: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631 #4: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:220 [inline] #4: ffff8880b8524088 (psi_seq){-.-.}-{0:0}, at: __schedule+0x1861/0x5de0 kernel/sched/core.c:6923 #5: ffffffff8e2d1680 (console_owner){-.-.}-{0:0}, at: console_lock_spinning_enable+0x61/0x80 kernel/printk/printk.c:1897 3 locks held by kworker/1:10/31225: #0: ffff8880236b8948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90004327d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffff8880293c4198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff8880293c4198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898 2 locks held by syz.2.8796/5647: #0: ffff88805f6f2118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_open_device drivers/input/evdev.c:384 [inline] #0: ffff88805f6f2118 (&evdev->mutex){+.+.}-{4:4}, at: evdev_open+0x2ec/0x690 drivers/input/evdev.c:478 #1: ffff888046ddf2c0 (&dev->mutex#2){+.+.}-{4:4}, at: class_mutex_intr_constructor include/linux/mutex.h:230 [inline] #1: ffff888046ddf2c0 (&dev->mutex#2){+.+.}-{4:4}, at: input_open_device+0x4b/0x3d0 drivers/input/input.c:583 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5874 Comm: kworker/0:4 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: usb_hub_wq hub_event RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3801 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3876 [inline] RIP: 0010:__lock_acquire+0xbd1/0x1c90 kernel/locking/lockdep.c:5237 Code: aa e5 96 48 8d 48 f8 48 85 c0 48 0f 45 c1 eb 04 48 83 e8 08 48 85 c0 74 16 48 8b 50 18 49 39 d0 0f 84 e3 fa ff ff 48 8b 40 08 <48> 85 c0 75 e1 4c 89 44 24 08 e8 b0 a8 ff ff 8b 05 4e 55 e9 0e 4c RSP: 0018:ffffc900000078c8 EFLAGS: 00000097 RAX: ffffffff93b24368 RBX: 0000000000047fd7 RCX: ffffffff93dc0f60 RDX: 0cff6fae7449078e RSI: 0000000055a1e19a RDI: ffff8880267e0bf8 RBP: ffff8880267e0000 R08: 0754d36cfbe89bc1 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880267e0b30 R13: ffff8880267e0bf8 R14: 000000003b867b4a R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff888124a0a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 0000000074073000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162 debug_object_assert_init+0x146/0x2f0 lib/debugobjects.c:1007 debug_timer_assert_init kernel/time/timer.c:803 [inline] debug_assert_init kernel/time/timer.c:848 [inline] __mod_timer+0xad/0xd30 kernel/time/timer.c:1025 mrp_join_timer+0xfc/0x120 net/802/mrp.c:612 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2034 [inline] RIP: 0010:vprintk_emit+0x526/0x680 kernel/printk/printk.c:2422 Code: 00 4d 85 ed 0f 85 19 01 00 00 e8 a5 1b 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 03 17 21 00 48 85 ed 0f 85 25 01 00 00 85 1b 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc900046c7668 EFLAGS: 00000287 RAX: 00000000000486a3 RBX: 0000000000000029 RCX: ffffc90019340000 RDX: 0000000000100000 RSI: ffffffff819bf125 RDI: 0000000000000007 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 1ffff920008d8ecf R13: 0000000000000200 R14: ffff88801eaf8000 R15: ffffc900046c7730 dev_vprintk_emit drivers/base/core.c:4914 [inline] dev_printk_emit+0xfa/0x140 drivers/base/core.c:4925 __dev_printk+0xf5/0x270 drivers/base/core.c:4937 _dev_info+0xe4/0x120 drivers/base/core.c:4983 usb_disconnect+0xec/0x9c0 drivers/usb/core/hub.c:2326 hub_port_connect drivers/usb/core/hub.c:5406 [inline] hub_port_connect_change drivers/usb/core/hub.c:5706 [inline] port_event drivers/usb/core/hub.c:5870 [inline] hub_event+0x1c81/0x4fe0 drivers/usb/core/hub.c:5952 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 xpad 3-1:179.65: xpad_irq_out - usb_submit_urb failed with result -19