------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 3 PID: 10621 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 3 UID: 0 PID: 10621 Comm: syz.4.1566 Not tainted 6.14.0-rc3-syzkaller-00012-g2408a807bfc3 #0
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 e8 56 f5 fc 84 db 0f 85 66 ff ff ff e8 3b 5c f5 fc c6 05 b7 5b 86 0b 01 90 48 c7 c7 80 01 d3 8b e8 d7 8d b5 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 18 5c f5 fc 0f b6 1d 92 5b 86 0b 31
RSP: 0018:ffffc9000d7c76b8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a1229
RDX: ffff88802a8e4880 RSI: ffffffff817a1236 RDI: 0000000000000001
RBP: ffff88802748c078 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000004 R12: ffff88802a4dbc00
R13: ffff88802748c078 R14: ffffffff85ebe6b0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88806a900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94cd771f98 CR3: 000000004aa1c000 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:275 [inline]
 __refcount_dec_and_test include/linux/refcount.h:307 [inline]
 refcount_dec_and_test include/linux/refcount.h:325 [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+0x140/0x2b0 lib/klist.c:249
 device_move+0x12d/0x10b0 drivers/base/core.c:4591
 hci_conn_del_sysfs+0x81/0x180 net/bluetooth/hci_sysfs.c:75
 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline]
 hci_conn_del+0x54e/0xdb0 net/bluetooth/hci_conn.c:1164
 hci_conn_hash_flush+0x4bf/0x790 net/bluetooth/hci_conn.c:2699
 hci_dev_close_sync+0x603/0x11a0 net/bluetooth/hci_sync.c:5197
 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:482
 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2677
 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:664
 __fput+0x3ff/0xb70 fs/file_table.c:464
 task_work_run+0x14e/0x250 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xad8/0x2d70 kernel/exit.c:938
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1087
 get_signal+0x24ed/0x26c0 kernel/signal.c:3036
 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f65a71bf6a5
Code: Unable to access opcode bytes at 0x7f65a71bf67b.
RSP: 002b:00007f65a7f89f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f65a73a5fa0 RCX: 00007f65a71bf6a5
RDX: 00007f65a7f89fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f65a720e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f65a73a5fa0 R15: 00007fff08189c28
 </TASK>