INFO: task syz-executor:21530 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:22264 pid:21530 tgid:21530 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227
 sync_inodes_sb+0x225/0xbf0 fs/fs-writeback.c:2944
 sync_filesystem+0x17a/0x230 fs/sync.c:64
 generic_shutdown_super+0x77/0x2d0 fs/super.c:625
 kill_block_super+0x44/0x90 fs/super.c:1725
 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2284
 deactivate_locked_super+0xbc/0x130 fs/super.c:476
 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:67 [inline]
 exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f01e219e017
RSP: 002b:00007ffcc77e1fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f01e2232120 RCX: 00007f01e219e017
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcc77e2060
RBP: 00007ffcc77e2060 R08: 00007ffcc77e3060 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcc77e30f0
R13: 00007f01e2232120 R14: 00000000001580ef R15: 00007ffcc77e3130
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
 #0: ffff888031cf8940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff888031cf8940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc90000127c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
 #1: ffffc90000127c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746
1 lock held by khungtaskd/32:
 #0: 
ffffffff8e95cd60
 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
9 locks held by kworker/u8:5/135:
1 lock held by dhcpcd/5280:
 #0: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x23d/0x370 net/ipv6/addrconf.c:4811
2 locks held by getty/5370:
 #0: ffff88803696e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:9/5640:
 #0: 
ffff888052285940
 (
(wq_completion)hci10
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3277 [inline]
, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: 
ffffc90003157c40
 (
(work_completion)(&hdev->cmd_sync_work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3278 [inline]
, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffff88806677cea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u8:23/19136:
 #0: ffff88813fe7c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff88813fe7c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: ffffc90003947c40
 (
(linkwatch_work).work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3278 [inline]
, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
2 locks held by syz-executor/21530:
 #0: ffff88805363a0d8 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88805363a0d8 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
 #0: ffff88805363a0d8 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
 #1: ffff888026524810 (&bdi->wb_switch_rwsem
){+.+.}-{4:4}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline]
, at: sync_inodes_sb+0x209/0xbf0 fs/fs-writeback.c:2942
3 locks held by kworker/u9:1/22311:
 #0: ffff888052771940 ((wq_completion)hci7){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
 #0: ffff888052771940 ((wq_completion)hci7){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: 
ffffc90003b57c40
 ((work_completion)(&hdev->cmd_sync_work)
){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffff88804e474ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u9:2/22626:
 #0: 
ffff88802a670940
 (
(wq_completion)hci9
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3277 [inline]
, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: 
ffffc90003897c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
ffffc90003897c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: ffff888032790ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
6 locks held by kworker/u8:3/23398:
 #0: ffff88801be86140 ((wq_completion)netns){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3277 [inline]
, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
 #1: 
ffffc900035bfc40
 (net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3278 [inline]
, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
 #2: 
ffffffff8fdc02e8
 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffff888037f3b128
 (
&dev->mutex
){....}-{4:4}
, at: device_lock include/linux/device.h:1040 [inline]
, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555
 #4: 
ffff888095309258 (&devlink->lock_key#26){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
ffff888095309258 (&devlink->lock_key#26){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
ffff888095309258 (&devlink->lock_key#26){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555
 #5: ffffffff8e962f38 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
2 locks held by syz-executor/23469:
 #0: ffffffff9030e1e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff9030e1e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff9030e1e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: 
ffffffff8fdcefc0
 (
rtnl_mutex
){+.+.}-{4:4}
, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108
9 locks held by syz-executor/23498:
 #0: ffff888035662410 (sb_writers#7
){.+.+}-{0:0}
, at: file_start_write include/linux/fs.h:2724 [inline]
, at: vfs_write+0x227/0xb90 fs/read_write.c:684
 #1: ffff888060176480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: 
ffff8880292f9d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
ffff8880292f9d28 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8f64ea20 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
 #4: 
ffff888078d05128
 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372
 #5: ffff888078d04258 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1799
 #6: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x13a/0x830 drivers/net/netdevsim/netdev.c:1187
 #7: ffff88804178cdc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2818 [inline]
 #7: ffff88804178cdc8 (&dev_instance_lock_key#23){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x588/0x22c0 net/core/dev.c:12378
 #8: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #8: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.9.3607/23985:
 #0: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdcefc0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7001

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 18071 Comm: kworker/u9:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: hci9 hci_cmd_timeout
RIP: 0010:stack_trace_consume_entry+0xa2/0x280 kernel/stacktrace.c:93
Code: cc 41 0f b6 04 17 84 c0 0f 85 78 01 00 00 44 89 23 b0 01 e9 99 00 00 00 31 c0 e9 92 00 00 00 48 89 f8 48 c1 e8 03 80 3c 10 00 <74> 29 49 89 ff 48 89 74 24 08 49 89 d4 4c 89 04 24 4c 89 cb e8 f5
RSP: 0018:ffffc90000a08958 EFLAGS: 00000246
RAX: 1ffff9200014114c RBX: ffffc90000a08a6c RCX: 0000000000000100
RDX: dffffc0000000000 RSI: ffffffff8230b37c RDI: ffffc90000a08a60
RBP: 1ffff9200014114e R08: ffffc90000a08a70 R09: 0000000000000002
R10: dffffc0000000000 R11: ffffffff81b0d880 R12: 0000000000000000
R13: 1ffff9200014114d R14: ffffc90000a08a68 R15: 1ffff9200014114d
FS:  0000000000000000(0000) GS:ffff888125390000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557342676138 CR3: 000000004b342000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 arch_stack_walk+0x10f/0x150 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6246 [inline]
 kmem_cache_free+0x182/0x650 mm/slub.c:6373
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline]
RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478
Code: 0f 84 44 ff ff ff e8 f2 26 21 00 fb eb 44 e8 ea 26 21 00 e8 d5 8f 03 0a 4d 85 f6 74 94 e8 db 26 21 00 fb 48 c7 c7 a0 f1 94 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 cb 18
RSP: 0018:ffffc900080cf7e0 EFLAGS: 00000293
RAX: ffffffff81a48555 RBX: ffffffff81a483cf RCX: ffff888031365c40
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e94f1a0
RBP: ffffc900080cf890 R08: ffffffff9030a1f7 R09: 1ffffffff206143e
R10: dffffc0000000000 R11: fffffbfff206143f R12: 0000000000000000
R13: 000000000000002a R14: 0000000000000200 R15: 1ffff92001019f00
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 bt_err+0x121/0x180 net/bluetooth/lib.c:296
 hci_cmd_timeout+0xd8/0x1e0 net/bluetooth/hci_core.c:1470
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>