------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 9004 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 9004 Comm: syz.1.876 Not tainted 6.14.0-rc6-syzkaller-01313-g23c9ff659140 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Code: 40 b5 80 8c e8 57 07 8c fc 90 0f 0b 90 90 eb 99 e8 0b 4b cc fc c6 05 85 8f 31 0b 01 90 48 c7 c7 a0 b5 80 8c e8 37 07 8c fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 e8 4a cc fc c6 05 5f 8f 31 0b 01 90
RSP: 0018:ffffc90004da7558 EFLAGS: 00010246
RAX: 07e8853ea6997400 RBX: ffff888028a69078 RCX: ffff88805fc55a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff8181ae52 R09: fffffbfff1d3a69c
R10: dffffc0000000000 R11: fffffbfff1d3a69c R12: ffff888028a69060
R13: ffffffff8638ea10 R14: 1ffff1100514d20c R15: ffff888028a69060
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8251572c20 CR3: 0000000062222000 CR4: 00000000003526f0
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+0x3ec/0x3f0 lib/klist.c:206
 klist_put lib/klist.c:217 [inline]
 klist_del lib/klist.c:230 [inline]
 klist_remove+0x25e/0x480 lib/klist.c:249
 device_move+0x1b4/0x710 drivers/base/core.c:4592
 hci_conn_del_sysfs+0xb5/0x170 net/bluetooth/hci_sysfs.c:75
 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline]
 hci_conn_del+0x8c4/0xc40 net/bluetooth/hci_conn.c:1164
 hci_conn_hash_flush+0x18e/0x240 net/bluetooth/hci_conn.c:2699
 hci_dev_close_sync+0xa8b/0x1260 net/bluetooth/hci_sync.c:5197
 hci_dev_do_close net/bluetooth/hci_core.c:483 [inline]
 hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2678
 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2a/0x28e0 kernel/exit.c:938
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 get_signal+0x168c/0x1720 kernel/signal.c:3036
 arch_do_signal_or_restart+0x96/0x860 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+0xce/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f107d98d169
Code: Unable to access opcode bytes at 0x7f107d98d13f.
RSP: 002b:00007f107e7560e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f107dba5fa8 RCX: 00007f107d98d169
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f107dba5fac
RBP: 00007f107dba5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 00007f107dba5fac
R13: 0000000000000000 R14: 00007ffdee5b1bc0 R15: 00007ffdee5b1ca8
 </TASK>