------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 24126 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 24126 Comm: syz-executor Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Code: ff 89 de e8 38 e8 e2 fc 84 db 0f 85 66 ff ff ff e8 4b ed e2 fc c6 05 79 f0 b7 0b 01 90 48 c7 c7 60 0e 15 8c e8 97 04 a2 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 28 ed e2 fc 0f b6 1d 54 f0 b7 0b 31
RSP: 0018:ffffc90004357948 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817aa1a8
RDX: ffff888025052440 RSI: ffffffff817aa1b5 RDI: 0000000000000001
RBP: ffff88804aa4b878 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88805f28cc00
R13: ffff88804aa4b878 R14: ffffffff86077550 R15: ffffffff908b2d60
FS:  0000000000000000(0000) GS:ffff888097561000(0000) knlGS:0000000000000000
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000ffe5cff8 CR3: 000000004fcd5000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 klist_dec_and_del lib/klist.c:206 [inline]
 klist_put+0x11b/0x1b0 lib/klist.c:217
 klist_del lib/klist.c:230 [inline]
 klist_remove+0x13f/0x2e0 lib/klist.c:249
 device_move+0x12d/0x10d0 drivers/base/core.c:4618
 hci_conn_del_sysfs+0x81/0x180 net/bluetooth/hci_sysfs.c:75
 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline]
 hci_conn_del+0x566/0xdc0 net/bluetooth/hci_conn.c:1173
 hci_conn_hash_flush+0x186/0x260 net/bluetooth/hci_conn.c:2561
 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5250
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2691
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665
 __fput+0x402/0xb70 fs/file_table.c:465
 task_work_run+0x14d/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x864/0x2bd0 kernel/exit.c:955
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1104
 __do_sys_exit_group kernel/exit.c:1115 [inline]
 __se_sys_exit_group kernel/exit.c:1113 [inline]
 __ia32_sys_exit_group+0x3e/0x50 kernel/exit.c:1113
 ia32_sys_call+0xd56/0x1c40 arch/x86/include/generated/asm/syscalls_32.h:253
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x3a0 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f03579
Code: Unable to access opcode bytes at 0xf7f0354f.
RSP: 002b:00000000ffe5f61c EFLAGS: 00000286 ORIG_RAX: 00000000000000fc
RAX: ffffffffffffffda RBX: 0000000000000043 RCX: 00000000ffe5f668
RDX: 0000000000000000 RSI: 00000000f7216b3f RDI: 00000000f71614c6
RBP: 00000000f7392ff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>