INFO: task syz-executor:15374 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:20488 pid:15374 tgid:15374 ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 __bch2_fs_stop+0x3cd/0x5b0 fs/bcachefs/super.c:651
 generic_shutdown_super+0x13b/0x2d0 fs/super.c:642
 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2303
 deactivate_locked_super+0xc6/0x130 fs/super.c:473
 cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435
 task_work_run+0x253/0x310 kernel/task_work.c:227
 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:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x210 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f26e658fc97
RSP: 002b:00007ffc49be7758 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f26e661089d RCX: 00007f26e658fc97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc49be7810
RBP: 00007ffc49be7810 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc49be88a0
R13: 00007f26e661089d R14: 00000000001570c5 R15: 00007ffc49be88e0
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
 #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764
2 locks held by kworker/u8:3/53:
1 lock held by udevd/5205:
2 locks held by getty/5597:
 #0: ffff8880330700a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900033462f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222
3 locks held by kworker/u8:25/13158:
 #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319
 #1: ffffc90005117c60 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90005117c60 ((work_completion)(&map->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998
1 lock held by syz-executor/15374:
 #0: ffff8880288300e0 (&type->s_umount_key#129){+.+.}-{4:4}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880288300e0 (&type->s_umount_key#129){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880288300e0 (&type->s_umount_key#129){+.+.}-{4:4}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
3 locks held by syz.9.2654/18474:
 #0: ffffffff900f0d10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x328/0x570 net/core/net_namespace.c:514
 #1: ffffffff900fd848 (rtnl_mutex){+.+.}-{4:4}, at: setup_net+0x652/0x9f0 net/core/net_namespace.c:386
 #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #2: ffffffff8ed43438 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x384/0x830 kernel/rcu/tree_exp.h:998

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:437
 kthread+0x7b9/0x940 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18474 Comm: syz.9.2654 Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__bfs kernel/locking/lockdep.c:1816 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1861 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2832 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3170 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3285 [inline]
RIP: 0010:validate_chain+0xe44/0x24e0 kernel/locking/lockdep.c:3909
Code: 8b 5c 24 30 49 83 c4 30 4c 39 e3 0f 84 b1 fe ff ff b0 01 4c 89 6c 24 40 eb 19 31 c0 4d 89 f7 4d 89 ee 4c 8b 6c 24 40 48 8b 1b <4c> 39 e3 0f 84 8f fe ff ff 48 89 6b 30 a8 01 74 ec 4d 89 f5 4d 89
RSP: 0018:ffffc90003b570a0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff97141d48 RCX: 00000000000001ab
RDX: 0000000000000008 RSI: ffff88803101e5d8 RDI: 00000000000003fd
RBP: ffffffff97071168 R08: ffffc90003b57060 R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff819ee7e0 R12: ffffffff94186098
R13: 0000000000000000 R14: ffff88803101e4c8 R15: ffff88803101e590
FS:  00007fea15a4e6c0(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d0a3067950 CR3: 000000004f166000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 class_raw_spinlock_constructor include/linux/spinlock.h:535 [inline]
 pcpu_alloc+0xb6/0x300 lib/debugobjects.c:281
 alloc_object+0xbf/0x310 lib/debugobjects.c:458
 lookup_object_or_alloc lib/debugobjects.c:685 [inline]
 debug_object_activate+0x266/0x5c0 lib/debugobjects.c:820
 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline]
 __call_rcu_common kernel/rcu/tree.c:3067 [inline]
 call_rcu+0x99/0xad0 kernel/rcu/tree.c:3202
 radix_tree_node_free lib/radix-tree.c:310 [inline]
 delete_node+0x1b2/0x780 lib/radix-tree.c:573
 radix_tree_delete_item+0x2e6/0x3f0 lib/radix-tree.c:1430
 kernfs_put+0x172/0x460 fs/kernfs/dir.c:588
 kernfs_remove_by_name_ns+0xb5/0x130 fs/kernfs/dir.c:1715
 kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0xfe/0x2c0 fs/sysfs/group.c:322
 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:346
 device_remove_groups drivers/base/core.c:2820 [inline]
 device_remove_attrs+0x25a/0x2b0 drivers/base/core.c:2956
 device_del+0x574/0x9b0 drivers/base/core.c:3854
 unregister_netdevice_many_notify+0x2069/0x2640 net/core/dev.c:12018
 setup_net+0x711/0x9f0 net/core/net_namespace.c:391
 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:518
 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
 ksys_unshare+0x5e2/0xad0 kernel/fork.c:3375
 __do_sys_unshare kernel/fork.c:3446 [inline]
 __se_sys_unshare kernel/fork.c:3444 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3444
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fea14b8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fea15a4e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fea14db5fa0 RCX: 00007fea14b8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000044040200
RBP: 00007fea14c10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fea14db5fa0 R15: 00007ffc021f5548
 </TASK>