INFO: task syz.2.47:5569 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc2-next-20241008-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.47        state:D stack:26832 pid:5569  tgid:5561  ppid:5232   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1895/0x4b30 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 chaoskey_release+0x169/0x2f0 drivers/usb/misc/chaoskey.c:322
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2f/0x28e0 kernel/exit.c:939
 do_group_exit+0x207/0x2c0 kernel/exit.c:1088
 get_signal+0x16a3/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fefec97dff9
RSP: 002b:00007fefec3de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: fffffffffffffe00 RBX: 00007fefecb36208 RCX: 00007fefec97dff9
RDX: 000000000000009a RSI: 0000000020000440 RDI: 0000000000000007
RBP: 00007fefec9f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fefecb36208 R15: 00007ffd16dad458
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-next-20241008-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6800 Comm: syz-executor Not tainted 6.12.0-rc2-next-20241008-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kernfs_drain+0x65/0x6d0 fs/kernfs/dir.c:481
Code: c7 44 24 40 b3 8a b5 41 48 c7 44 24 48 f2 97 09 8e 48 c7 44 24 50 c0 cb 3c 82 48 8d 44 24 40 48 c1 e8 03 c7 04 18 f1 f1 f1 f1 <c7> 44 18 09 f3 f3 f3 f3 66 c7 44 18 0d f3 f3 48 89 44 24 38 c6 44
RSP: 0018:ffffc9000cf7f800 EFLAGS: 00000a02
RAX: 1ffff920019eff08 RBX: dffffc0000000000 RCX: ffffffff823cd67e
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88804c01fc30
RBP: ffffc9000cf7f920 R08: ffff88804c01fc33 R09: 1ffff11009803f86
R10: dffffc0000000000 R11: ffffed1009803f87 R12: dffffc0000000000
R13: 1ffff11009803f92 R14: ffff88804c01fc30 R15: ffff88804c01fc30
FS:  00005555558a3500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c46ee5b CR3: 0000000027b5c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __kernfs_remove+0x400/0x870 fs/kernfs/dir.c:1486
 kernfs_remove_by_name_ns+0xdc/0x160 fs/kernfs/dir.c:1694
 kernfs_remove_by_name include/linux/kernfs.h:625 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xfe/0x2c0 fs/sysfs/group.c:319
 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:343
 device_remove_groups drivers/base/core.c:2829 [inline]
 device_remove_attrs+0x23a/0x290 drivers/base/core.c:2965
 device_del+0x572/0x9b0 drivers/base/core.c:3863
 device_unregister+0x20/0xc0 drivers/base/core.c:3905
 bdi_unregister+0x4d2/0x5d0 mm/backing-dev.c:1170
 generic_shutdown_super+0x23b/0x2d0 fs/super.c:682
 kill_anon_super+0x3b/0x70 fs/super.c:1237
 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2121
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f38c077f327
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffea3899788 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f38c077f327
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffea3899840
RBP: 00007ffea3899840 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffea389a8c0
R13: 00007f38c07f0134 R14: 0000000000039f62 R15: 00007ffea389a900
 </TASK>