INFO: task syz.3.2385:15473 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2385      state:D stack:27480 pid:15473 tgid:15473 ppid:5809   task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
 __flush_work+0x7d7/0xcc0 kernel/workqueue.c:4277
 __cancel_work_sync kernel/workqueue.c:4397 [inline]
 cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4434
 hci_cmd_sync_clear+0x33/0x100 net/bluetooth/hci_sync.c:655
 hci_unregister_dev+0x1cc/0x680 net/bluetooth/hci_core.c:2711
 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x87f/0x2bd0 kernel/exit.c:971
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80e55c2005
RSP: 002b:00007f80e63a9f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f80e57e5fa0 RCX: 00007f80e55c2005
RDX: 00007f80e63a9fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f80e5613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f80e57e6038 R14: 00007f80e57e5fa0 R15: 00007ffec0407568
 </TASK>

Showing all locks held in the system:
1 lock held by ksoftirqd/0/15:
1 lock held by khungtaskd/31:
 #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:4/65:
 #0: ffff88801badc948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc9000215fc90 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffffffff90128250 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x830 net/core/net_namespace.c:670
 #3: ffff8880793654e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x151/0x3f0 drivers/net/wireguard/device.c:249
 #4: ffffffff8e3d4d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by getty/5572:
 #0: ffff88814e07f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:8/5825:
 #0: ffff888030eeb948 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc9000216fc90 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff888029c70ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x175/0x470 net/bluetooth/hci_sync.c:331
1 lock held by syz.6.1691/12732:
 #0: ffffffff9013ea28 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff9013ea28 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x230 drivers/net/tun.c:3436
4 locks held by syz-executor/17686:
 #0: ffff888057dbcec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xc0 net/bluetooth/hci_core.c:499
 #1: ffff888057dbc0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3af/0x1260 net/bluetooth/hci_sync.c:5314
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x290 net/bluetooth/hci_conn.c:2637
 #3: ffff8880342e3338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x80/0x760 net/bluetooth/l2cap_core.c:1763
1 lock held by syz.7.3024/17866:
 #0: ffff88804cc7fac8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff88804cc7fac8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:661
2 locks held by kworker/1:4/18974:
 #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc9000c4d7c90 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
1 lock held by syz.7.3427/19264:
 #0: ffff8880754fbb88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff8880754fbb88 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:661
3 locks held by syz-executor/19409:
 #0: ffff888073478ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xc0 net/bluetooth/hci_core.c:499
 #1: ffff8880734780c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3af/0x1260 net/bluetooth/hci_sync.c:5314
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x290 net/bluetooth/hci_conn.c:2637
3 locks held by syz.2.3512/19562:
 #0: ffff888056dfcec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0xc0 net/bluetooth/hci_core.c:499
 #1: ffff888056dfc0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3af/0x1260 net/bluetooth/hci_sync.c:5314
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline]
 #2: ffffffff903bb848 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xbb/0x290 net/bluetooth/hci_conn.c:2637

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18016 Comm: syz.7.3067 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__rcu_read_lock+0xa7/0xf0 kernel/rcu/tree_plugin.h:416
Code: 48 b8 00 00 00 00 00 fc ff df 89 9d 84 04 00 00 65 48 8b 1d 53 34 0f 12 48 8d bb 84 04 00 00 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 1f 8b 83 84 04 00
RSP: 0018:ffffc90003fff608 EFLAGS: 00000a07
RAX: dffffc0000000000 RBX: ffff88802b57a4c0 RCX: ffffc90003fff778
RDX: 0000000000000000 RSI: ffff88802b57a4c0 RDI: ffff88802b57a944
RBP: ffff88802b57a4c0 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90003fff6e0 R11: ffff88802b57aff0 R12: fffff520007ffede
R13: ffffc90003fff6e0 R14: ffffc90003fff6e0 R15: ffffc90003fff6e8
FS:  0000000000000000(0000) GS:ffff8881248fd000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da15ff8 CR3: 000000000e184000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_lock include/linux/rcupdate.h:865 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xae/0x20a0 arch/x86/kernel/unwind_orc.c:479
 __unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:165
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
 vfree+0x1fd/0xb50 mm/vmalloc.c:3466
 kcov_put kernel/kcov.c:439 [inline]
 kcov_put kernel/kcov.c:435 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:535
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x87f/0x2bd0 kernel/exit.c:971
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f765e3c2005
Code: Unable to access opcode bytes at 0x7f765e3c1fdb.
RSP: 002b:00007f765f25cf80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f765e5e5fa0 RCX: 00007f765e3c2005
RDX: 00007f765f25cfc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f765e413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f765e5e6038 R14: 00007f765e5e5fa0 R15: 00007ffc398be838
 </TASK>