INFO: task syz.1.765:8890 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.765       state:D stack:26288 pid:8890  ppid:5771   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 device_lock include/linux/device.h:1094 [inline]
 usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
 chrdev_open+0x58c/0x600 fs/char_dev.c:414
 do_dentry_open+0x880/0x14b0 fs/open.c:929
 do_open fs/namei.c:3683 [inline]
 path_openat+0x284f/0x3270 fs/namei.c:3844
 do_filp_open+0x1f2/0x430 fs/namei.c:3871
 do_sys_openat2+0x134/0x1d0 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f38ea15e98e
RSP: 002b:00007f38eb098b28 EFLAGS: 00000246
 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f38eb0996c0 RCX: 00007f38ea15e98e
RDX: 0000000000000000 RSI: 00007f38eb098c00 RDI: ffffffffffffff9c
RBP: 00007f38eb098c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f38ea426218 R14: 00007f38ea426180 R15: 00007ffe4e6f3798
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:1/9:
 #0: ffff888017c70d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c70d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900000e7d00 ((work_completion)(&wfc.work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900000e7d00 ((work_completion)(&wfc.work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: cpus_write_lock kernel/cpu.c:507 [inline]
 #2: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: _cpu_down+0xfe/0x1100 kernel/cpu.c:1444
2 locks held by cpuhp/1/20:
 #0: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: lockdep_acquire_cpus_lock kernel/cpu.c:538 [inline]
 #0: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x128/0x850 kernel/cpu.c:1069
 #1: ffffffff8cfcd5c0 (cpuhp_state-down){+.+.}-{0:0}, at: lockdep_acquire_cpus_lock kernel/cpu.c:538 [inline]
 #1: ffffffff8cfcd5c0 (cpuhp_state-down){+.+.}-{0:0}, at: cpuhp_thread_fun+0x128/0x850 kernel/cpu.c:1069
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6669
3 locks held by kworker/u4:5/171:
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c71938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90002f07d00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90002f07d00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:219
6 locks held by kworker/0:2/173:
2 locks held by getty/5529:
 #0: ffff8880318fa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
6 locks held by kworker/0:3/5761:
3 locks held by kworker/0:4/5815:
 #0: ffff888017c70d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888017c70d38 ((wq_completion)events#2){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90004887d00 ((shepherd).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90004887d00 ((shepherd).work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8cfcd450 (cpu_hotplug_lock){++++}-{0:0}, at: vmstat_shepherd+0x1d/0x1a0 mm/vmstat.c:2025
1 lock held by syz.1.765/8890:
 #0: ffff8880255f11d8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #0: ffff8880255f11d8 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x152/0x770 drivers/usb/core/devio.c:1051
7 locks held by syz.4.1113/10139:
 #0: ffff88802fc30348 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2a3/0x330 fs/file.c:1040
 #1: ffff88805ef30418 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
 #2: ffff88802692cc88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1dc/0x520 fs/kernfs/file.c:343
 #3: ffff888145a63ca0 (kn->active#66){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #3: ffff888145a63ca0 (kn->active#66){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344
 #4: ffffffff8da11d28 (device_hotplug_lock){+.+.}-{3:3}, at: lock_device_hotplug_sysfs drivers/base/core.c:2374 [inline]
 #4: ffffffff8da11d28 (device_hotplug_lock){+.+.}-{3:3}, at: online_store+0xb1/0x320 drivers/base/core.c:2822
 #5: ffff8880b8f27b58 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1094 [inline]
 #5: ffff8880b8f27b58 (&dev->mutex){....}-{3:3}, at: device_offline+0x17c/0x3b0 drivers/base/core.c:4314
 #6: ffffffff8cfcd328 (cpu_add_remove_lock){+.+.}-{3:3}, at: cpu_maps_update_begin kernel/cpu.c:469 [inline]
 #6: ffffffff8cfcd328 (cpu_add_remove_lock){+.+.}-{3:3}, at: cpu_down+0x7f/0x1f0 kernel/cpu.c:1540
2 locks held by dhcpcd/10149:
 #0: ffff88804cbd6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
 #0: ffff88804cbd6130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3288
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by dhcpcd/10150:
 #0: ffff88807b84c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
 #0: ffff88807b84c130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3288
2 locks held by dhcpcd/10151:
 #0: ffff888021834130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
 #0: ffff888021834130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3288
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #1: ffffffff8d137ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by dhcpcd/10152:
 #0: ffff88802eac2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
 #0: ffff88802eac2130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xd40 net/packet/af_packet.c:3288

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>