------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 5240 at lib/refcount.c:28 refcount_warn_saturate+0x11a/0x1d0
Modules linked in:
CPU: 1 UID: 0 PID: 5240 Comm: kworker/u11:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: hci2 hci_cmd_sync_work
RIP: 0010:refcount_warn_saturate+0x11a/0x1d0
Code: 00 b3 e2 8b e8 f7 38 bb fc 90 0f 0b 90 90 eb d7 e8 4b 9a f7 fc c6 05 b7 6f c5 0a 01 90 48 c7 c7 60 b3 e2 8b e8 d7 38 bb fc 90 <0f> 0b 90 90 eb b7 e8 2b 9a f7 fc c6 05 94 6f c5 0a 01 90 48 c7 c7
RSP: 0018:ffffc9000aad7658 EFLAGS: 00010246
RAX: d37b801b381ec100 RBX: 0000000000000003 RCX: ffff888108779cc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffff888136624253 R09: 1ffff11026cc484a
R10: dffffc0000000000 R11: ffffed1026cc484b R12: ffff888109cc7c00
R13: ffff88802ecfa860 R14: ffff88802ecfa878 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c240c9f CR3: 0000000110e4a000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 klist_dec_and_del+0x3c7/0x3d0
 klist_remove+0x1bd/0x340
 device_move+0x193/0x700
 hci_conn_del_sysfs+0xb8/0x170
 hci_conn_del+0xc33/0x11b0
 hci_abort_conn_sync+0x658/0xe30
 hci_cmd_sync_work+0x213/0x3a0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
