INFO: task kworker/1:21:7337 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:21    state:D stack:22800 pid: 7337 ppid:     2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
 __device_release_driver drivers/base/dd.c:1249 [inline]
 device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3615
 snd_seq_device_dev_disconnect+0x39/0x40 sound/core/seq_device.c:182
 __snd_device_disconnect sound/core/device.c:63 [inline]
 snd_device_disconnect_all+0xcf/0x200 sound/core/device.c:215
 snd_card_disconnect+0x385/0x7d0 sound/core/init.c:528
 usb_audio_disconnect+0x283/0x6f0 sound/usb/card.c:971
 usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
 __device_release_driver drivers/base/dd.c:1249 [inline]
 device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
 bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
 device_del+0x63f/0xa80 drivers/base/core.c:3615
 usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
 usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2287
 hub_port_connect drivers/usb/core/hub.c:5341 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
 port_event drivers/usb/core/hub.c:5799 [inline]
 hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5881
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:2/154:
 #0: ffff888016c79138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90001f37d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:251
1 lock held by dhcpcd/3850:
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
2 locks held by getty/3947:
 #0: ffff88802cdcb098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by kworker/u4:23/4774:
3 locks held by kworker/1:19/7335:
 #0: ffff88802b6d9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90003427d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4120
8 locks held by kworker/1:21/7337:
 #0: ffff888141b91d38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900034bfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffff888023fac220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #2: ffff888023fac220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5827
 #3: ffff888020f05220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #3: ffff888020f05220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2278
 #4: ffff88802385a1a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #4: ffff88802385a1a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #4: ffff88802385a1a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #5: ffffffff8d3f5608 (register_mutex#7){+.+.}-{3:3}, at: usb_audio_disconnect+0xd0/0x6f0 sound/usb/card.c:960
 #6: ffff8880232c6200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #6: ffff8880232c6200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #6: ffff8880232c6200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #7: ffffffff8d3bc7a8 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
3 locks held by kworker/0:7/10144:
 #0: ffff88802b6d9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000361fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x1530 net/ipv6/addrconf.c:4120
3 locks held by kworker/1:1/11024:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc9000355fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
8 locks held by syz.8.1736/12423:
 #0: ffff888054a3aaf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88814675e460 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffff88801bb84e88 (&buffer->mutex){+.+.}-{3:3}, at: configfs_write_iter+0x7d/0x400 fs/configfs/file.c:226
 #3: ffff888023cc7178 (&p->frag_sem){++++}-{3:3}, at: flush_write_buffer fs/configfs/file.c:205 [inline]
 #3: ffff888023cc7178 (&p->frag_sem){++++}-{3:3}, at: configfs_write_iter+0x20e/0x400 fs/configfs/file.c:229
 #4: ffff8880608e1310 (&gi->lock){+.+.}-{3:3}, at: gadget_dev_desc_UDC_store+0xed/0x2e0 drivers/usb/gadget/configfs.c:276
 #5: ffffffff8ced1088 (udc_lock){+.+.}-{3:3}, at: usb_gadget_unregister_driver+0x56/0x4c0 drivers/usb/gadget/udc/core.c:1651
 #6: ffff88801f5c3200 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
 #6: ffff88801f5c3200 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
 #6: ffff88801f5c3200 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
 #7: ffffffff8d3bc7a8 (register_mutex#6){+.+.}-{3:3}, at: snd_seq_midisynth_remove+0x68/0x4e0 sound/core/seq/seq_midi.c:432
1 lock held by syz.9.2267/14101:
 #0: ffffffff8ced1088 (udc_lock){+.+.}-{3:3}, at: usb_gadget_probe_driver+0x7b/0x380 drivers/usb/gadget/udc/core.c:1604
1 lock held by syz-executor/14361:
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
2 locks held by kworker/1:2/14554:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90003e5fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
2 locks held by syz.4.2406/14578:
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.6.2407/14587:
 #0: ffffffff8d44cc08 (rtnl_mutex){+.+.}-{3:3}, at: raw_setsockopt+0x751/0x1200 net/can/raw.c:568

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4172 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline]
RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline]
RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline]
RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 9f 03 d5 02 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000dd07f8 EFLAGS: 00000046
RAX: 0000000000000613 RBX: 0000000000000613 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 0000000000000613 RDI: 0000000000000838
RBP: 0000000000000000 R08: ffffffff8d8b0d6f R09: 1ffffffff1b161ad
R10: dffffc0000000000 R11: fffffbfff1b161ae R12: dffffc0000000000
R13: 00000000100058eb R14: ffffffff8be3d9d8 R15: dffffc0000000000
FS:  0000555591206500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c312311 CR3: 0000000072627000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 apic_write arch/x86/include/asm/apic.h:395 [inline]
 lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:468
 clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334
 hrtimer_interrupt+0x4cb/0x8b0 kernel/time/hrtimer.c:1824
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xbc/0x120 kernel/locking/spinlock.c:194
Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> ef 90 88 f7 65 8b 05 60 b8 38 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90000dd0a40 EFLAGS: 00000206
RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: a6a6a447c22d1800
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: ffffc90000dd0ad8 R08: ffffffff901ef18f R09: 1ffffffff203de31
R10: dffffc0000000000 R11: fffffbfff203de32 R12: dffffc0000000000
R13: ffff8880b91280c0 R14: ffff8880b91280c0 R15: 1ffff920001ba148
 __mod_timer+0x925/0xd20 kernel/time/timer.c:1081
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:blkcg_maybe_throttle_current+0x1/0x6e0 block/blk-cgroup.c:1743
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 0b ff ff ff 4c 89 ff e8 c6 7e e7 fd e9 fe fe ff ff 90 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 18 48 bb 00 00 00 00 00 fc ff
RSP: 0018:ffffc90002d3fec0 EFLAGS: 00000246
RAX: a6a6a447c22d1800 RBX: ffffc90002d3ff58 RCX: a6a6a447c22d1800
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000000
RBP: ffffc90002d3ff48 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff2c675b8 R12: 0000000000000000
R13: 0000000000000000 R14: ffff888079fe8000 R15: ffff888079fe8000
 tracehook_notify_resume include/linux/tracehook.h:199 [inline]
 exit_to_user_mode_loop+0xd1/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc882a8d257
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe6a0d6e80 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000555591206500 RCX: 00007fc882a8d257
RDX: 00007ffe6a0d6ec0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffe6a0d73a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffe6a0d6efc R14: 00007ffe6a0d6f90 R15: 0000000000000000
 </TASK>