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: 7325 Comm: khidpd_10cf5508 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 assign_lock_key kernel/locking/lockdep.c:984 [inline]
 register_lock_class+0x549/0x560 kernel/locking/lockdep.c:1299
 __lock_acquire+0x3cb/0x2630 kernel/locking/lockdep.c:5112
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:570 [inline]
 set_task_blocked_on include/linux/sched.h:2211 [inline]
 __mutex_lock_common kernel/locking/mutex.c:701 [inline]
 __mutex_lock+0xcc7/0x1b90 kernel/locking/mutex.c:776
 l2cap_unregister_user+0x71/0x240 net/bluetooth/l2cap_core.c:1721
 hidp_session_thread+0x459/0x680 net/bluetooth/hidp/core.c:1304
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
 non-slab/vmalloc memory
list_del corruption. prev->next should be ffffc90005a8fc50, but was 0000000000000000. (prev=ffff8880794480a8)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:62!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 7325 Comm: khidpd_10cf5508 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026
RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62
Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 0a 1b 8c e8 27 de 23 fc 90 <0f> 0b 4c 89 e7 e8 6c b9 51 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90005a8fb20 EFLAGS: 00010082
RAX: 000000000000006d RBX: ffffc90005a8fc50 RCX: 0000000000000000
RDX: 000000000000006d RSI: ffffffff81e7a3a9 RDI: fffff52000b51f55
RBP: ffff8880794480a8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000001 R12: ffff8880794480a8
R13: 0000000000000246 R14: ffffc90005a8fc50 R15: ffff888036c14980
FS:  0000000000000000(0000) GS:ffff888124345000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf1cf456b8 CR3: 000000007c40e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __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+0x1a/0x1a0 kernel/locking/mutex.c:221
 __mutex_lock_common kernel/locking/mutex.c:742 [inline]
 __mutex_lock+0x828/0x1b90 kernel/locking/mutex.c:776
 l2cap_unregister_user+0x71/0x240 net/bluetooth/l2cap_core.c:1721
 hidp_session_thread+0x459/0x680 net/bluetooth/hidp/core.c:1304
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62
Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 0a 1b 8c e8 27 de 23 fc 90 <0f> 0b 4c 89 e7 e8 6c b9 51 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc90005a8fb20 EFLAGS: 00010082
RAX: 000000000000006d RBX: ffffc90005a8fc50 RCX: 0000000000000000
RDX: 000000000000006d RSI: ffffffff81e7a3a9 RDI: fffff52000b51f55
RBP: ffff8880794480a8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000001 R12: ffff8880794480a8
R13: 0000000000000246 R14: ffffc90005a8fc50 R15: ffff888036c14980
FS:  0000000000000000(0000) GS:ffff888124345000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdf1cf456b8 CR3: 000000007c40e000 CR4: 00000000003526f0