INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 0 UID: 0 PID: 7179 Comm: khidpd_00075505 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 assign_lock_key+0x178/0x188 kernel/locking/lockdep.c:984
 register_lock_class+0xf0/0x348 kernel/locking/lockdep.c:1299
 __lock_acquire+0xbc/0x30a4 kernel/locking/lockdep.c:5112
 lock_acquire+0x140/0x2e0 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x5c/0x7c kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:557 [inline]
 set_task_blocked_on include/linux/sched.h:2165 [inline]
 __mutex_lock_common+0xd24/0x2678 kernel/locking/mutex.c:701
 __mutex_lock kernel/locking/mutex.c:776 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:828
 l2cap_unregister_user+0x74/0x190 net/bluetooth/l2cap_core.c:1729
 hidp_session_thread+0x3d0/0x490 net/bluetooth/hidp/core.c:1304
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
 non-slab/vmalloc memory
list_del corruption. prev->next should be ffff80009d437ba0, but was 0000000000000000. (prev=ffff0000c84100a8)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:64!
Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
Modules linked in:
CPU: 0 UID: 0 PID: 7179 Comm: khidpd_00075505 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025
pstate: 634000c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62
lr : __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62
sp : ffff80009d437a00
x29: ffff80009d437a00 x28: ffff80009d437ba0 x27: ffff80009d437b80
x26: ffff0000cce8dfd8 x25: 0000000000000000 x24: dfff800000000000
x23: 1fffe00019082015 x22: dfff800000000000 x21: ffff0000c84100a8
x20: ffff0000c84100a8 x19: ffff80009d437ba0 x18: 1fffe00033781890
x17: 20747562202c3061 x16: ffff800082e5e68c x15: 0000000000000001
x14: 1ffff0001229b888 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000001061 x10: 0000000000ff0100 x9 : 765ecfa446a10f00
x8 : 765ecfa446a10f00 x7 : 0000000000000001 x6 : ffff8000805761f8
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000807f1034
x2 : 0000000000000001 x1 : 0000000000000002 x0 : 000000000000006d
Call trace:
 __list_del_entry_valid_or_report+0x17c/0x1b4 lib/list_debug.c:62 (P)
 __list_del_entry_valid include/linux/list.h:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del include/linux/list.h:237 [inline]
 __mutex_remove_waiter kernel/locking/mutex.c:221 [inline]
 __mutex_lock_common+0x114c/0x2678 kernel/locking/mutex.c:742
 __mutex_lock kernel/locking/mutex.c:776 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:828
 l2cap_unregister_user+0x74/0x190 net/bluetooth/l2cap_core.c:1729
 hidp_session_thread+0x3d0/0x490 net/bluetooth/hidp/core.c:1304
 kthread+0x5fc/0x75c kernel/kthread.c:463
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:844
Code: 91058000 aa1303e1 aa1503e3 974a97c3 (d4210000) 
---[ end trace 0000000000000000 ]---