syzbot

INFO: task kworker/0:0:8 blocked for more than 174 seconds.
      Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0     state:D stack:19320 pid:8     tgid:8     ppid:2      flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x184f/0x4c30 kernel/sched/core.c:6693
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6842
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 usb_lock_port drivers/usb/core/hub.c:3206 [inline]
 hub_event+0x7d5/0x5150 drivers/usb/core/hub.c:5902
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
7 locks held by kworker/0:0/8:
 #0: ffff888143ed1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff888143ed1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900000d7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff888028bed190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #2: ffff888028bed190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849
 #3: ffff8880613b1190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff8880613b1190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2295
 #4: ffff88807c638160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff88807c638160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff88807c638160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
 #5: ffff88805ccada20 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #5: ffff88805ccada20 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #5: ffff88805ccada20 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
 #6: ffffffff8fb158f0 (minors_rwsem){+.+.}-{3:3}, at: hidraw_disconnect+0x42/0x60 drivers/hid/hidraw.c:640
2 locks held by kworker/u8:0/11:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90000107d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90000107d00 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
3 locks held by kdevtmpfs/27:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
3 locks held by kworker/u8:2/35:
3 locks held by kworker/u8:4/62:
 #0: ffff888030cb8948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff888030cb8948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900015e7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900015e7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd3cc8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4736
3 locks held by kworker/u8:5/959:
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000430fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000430fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd3cc8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276
3 locks held by kworker/1:2/1199:
 #0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac81948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90004867d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90004867d00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcd3cc8 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x99/0xfd0 net/wireless/reg.c:2480
2 locks held by kworker/u8:8/2976:
2 locks held by syslogd/5198:
1 lock held by klogd/5205:
3 locks held by udevd/5216:
2 locks held by getty/5605:
 #0: ffff8880318a60a0 (&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+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
5 locks held by kworker/u9:7/5857:
 #0: ffff88805c3d7148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88805c3d7148 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc90003cafd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc90003cafd00 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff88807eb7cd80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331
 #3: ffff88807eb7c078 (&hdev->lock){+.+.}-{3:3}, at: hci_abort_conn_sync+0x1ea/0xe00 net/bluetooth/hci_sync.c:5577
 #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline]
 #4: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976
4 locks held by udevd/5864:
 #0: ffff8880536cf0a0 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182
 #1: ffff8880250b4c88 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff88806a2a22d8 (kn->active#5){++++}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff888024ec5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff888024ec5190 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17d/0x340 drivers/base/core.c:2736
2 locks held by syz-executor/5865:
5 locks held by kworker/0:4/5898:
 #0: ffff888143ed1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff888143ed1548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900041dfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900041dfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff8881447eb190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #2: ffff8881447eb190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849
 #3: ffff888024ec5190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #3: ffff888024ec5190 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2295
 #4: ffff888027d9d160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline]
 #4: ffff888027d9d160 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff888027d9d160 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
4 locks held by kworker/0:5/5905:
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88801ac80948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc9000433fd00 ((work_completion)(&dev->request_module_wk)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc9000433fd00 ((work_completion)(&dev->request_module_wk)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8f90db28 (em28xx_devlist_mutex){+.+.}-{3:3}, at: em28xx_init_extension+0x32/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1113
 #3: ffff88805ec45b78 (&dev->lock#2){+.+.}-{3:3}, at: em28xx_dvb_init+0x2d0/0x4680 drivers/media/usb/em28xx/em28xx-dvb.c:1533
4 locks held by syz-executor/6237:
 #0: ffff88805bd88d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline]
 #0: ffff88805bd88d80 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2698
 #1: ffff88805bd88078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5193
 #2: ffffffff8fe40568 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1972 [inline]
 #2: ffffffff8fe40568 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa6/0x240 net/bluetooth/hci_conn.c:2592
 #3: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #3: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976
9 locks held by syz-executor/7196:
2 locks held by syz.6.299/7372:
2 locks held by sed/7383:
3 locks held by modprobe/7386:
3 locks held by syz-executor/7393:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 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+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7394 Comm: udevd Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:lockdep_hardirqs_on_prepare+0x604/0x780 kernel/locking/lockdep.c:4387
Code: 90 80 e1 07 80 c1 03 38 c1 0f 8c 94 fa ff ff 48 c7 c7 0c 3f 1d 90 e8 1b a5 8e 00 48 ba 00 00 00 00 00 fc ff df e9 79 fa ff ff <48> c7 c1 40 79 3d 9a 80 e1 07 80 c1 03 38 c1 0f 8c b8 fa ff ff 48
RSP: 0000:ffffc900043a7e00 EFLAGS: 00000002
RAX: 0000000000000004 RBX: 0000000000000000 RCX: ffffffff819cafec
RDX: dffffc0000000000 RSI: ffffffff8c610cc0 RDI: ffffffff8c610c80
RBP: ffffc900043a7ec0 R08: ffffffff901d0caf R09: 1ffffffff203a195
R10: dffffc0000000000 R11: fffffbfff203a196 R12: ffff888035263c00
R13: 0000000000000255 R14: ffffc900043a7f58 R15: 1ffff92000874fc4
FS:  00007fe004165c80(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005646b02095d8 CR3: 0000000029a14000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 exit_to_user_mode include/linux/entry-common.h:360 [inline]
 irqentry_exit_to_user_mode+0x1a9/0x280 kernel/entry/common.c:233
 exc_page_fault+0x590/0x8c0 arch/x86/mm/fault.c:1542
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fe003cc71a6
Code: f2 e6 0e 00 eb 81 49 89 c5 49 ff c0 49 c1 ed 0c 4c 33 28 4c 89 e8 eb c0 44 0f b7 04 4e 4c 89 c0 4d 39 d8 73 2a 48 89 fa ff c0 <4c> 89 4d 18 48 c1 ea 0c 48 33 94 ce 80 00 00 00 48 89 55 10 48 89
RSP: 002b:00007fffa4942690 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 0000000000000020 RCX: 0000000000000000
RDX: 00005646b02095d0 RSI: 00005646b01ec010 RDI: 00005646b02095d0
RBP: 00005646b02095c0 R08: 0000000000000003 R09: 866a16c5d6956ce8
R10: 7e72b9308a59fe8e R11: 0000000000000007 R12: 0000000000000000
R13: 0000564685c87040 R14: 00007fe003df1aa0 R15: 00005646b01ec910
 </TASK>