Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 sysfs_warn_dup fs/sysfs/dir.c:30 [inline]
 sysfs_create_dir_ns+0x271/0x2a0 fs/sysfs/dir.c:63
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x62b/0xd00 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x163/0x240 lib/kobject.c:426
 device_add+0x408/0xb70 drivers/base/core.c:3629
 hci_conn_add_sysfs+0xd5/0x210 net/bluetooth/hci_sysfs.c:48
 le_conn_complete_evt+0xf1d/0x1430 net/bluetooth/hci_event.c:5842
 hci_le_enh_conn_complete_evt+0x189/0x490 net/bluetooth/hci_event.c:5887
 hci_event_func net/bluetooth/hci_event.c:7781 [inline]
 hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838
 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
kobject: kobject_add_internal failed for hci0:0 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
sysfs: cannot create duplicate filename '/devices/virtual/bluetooth/hci0/hci0:0'
CPU: 0 UID: 0 PID: 5298 Comm: kworker/u5:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 sysfs_warn_dup fs/sysfs/dir.c:30 [inline]
 sysfs_create_dir_ns+0x271/0x2a0 fs/sysfs/dir.c:63
 create_dir lib/kobject.c:73 [inline]
 kobject_add_internal+0x62b/0xd00 lib/kobject.c:240
 kobject_add_varg lib/kobject.c:374 [inline]
 kobject_add+0x163/0x240 lib/kobject.c:426
 device_add+0x408/0xb70 drivers/base/core.c:3629
 hci_conn_add_sysfs+0xd5/0x210 net/bluetooth/hci_sysfs.c:48
 le_conn_complete_evt+0xf1d/0x1430 net/bluetooth/hci_event.c:5842
 hci_le_enh_conn_complete_evt+0x189/0x490 net/bluetooth/hci_event.c:5887
 hci_event_func net/bluetooth/hci_event.c:7781 [inline]
 hci_event_packet+0x7af/0x12c0 net/bluetooth/hci_event.c:7838
 hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
kobject: kobject_add_internal failed for hci0:0 with -EEXIST, don't try to register things with the same name in the same directory.
Bluetooth: hci0: failed to register connection device
Bluetooth: hci0: unexpected event 0x06 length: 4 > 3
Bluetooth: hci0: command tx timeout
------------[ cut here ]------------
refcnt < 0
WARNING: net/bluetooth/hci_conn.c:567 at hci_conn_timeout+0xff/0x2c0 net/bluetooth/hci_conn.c:567, CPU#0: kworker/u5:2/5298
Modules linked in:
CPU: 0 UID: 0 PID: 5298 Comm: kworker/u5:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: hci0 hci_conn_timeout
RIP: 0010:hci_conn_timeout+0xff/0x2c0 net/bluetooth/hci_conn.c:567
Code: 48 89 df e8 63 a0 09 00 eb 07 e8 0c 95 21 f7 b0 13 0f b6 f0 48 89 df 5b 41 5c 41 5e 41 5f 5d e9 97 a8 fe ff e8 f2 94 21 f7 90 <0f> 0b 90 eb 8c 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 31 ff ff ff
RSP: 0018:ffffc9000e1efab0 EFLAGS: 00010293
RAX: ffffffff8aa4297e RBX: ffff8880124c8000 RCX: ffff888000f624c0
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000000
RBP: 00000000ffffffff R08: ffff8880124c8013 R09: 1ffff11002499002
R10: dffffc0000000000 R11: ffffed1002499003 R12: dffffc0000000000
R13: ffff88801abc8018 R14: ffff8880124c8a40 R15: ffff8880124c8010
FS:  0000000000000000(0000) GS:ffff88808ca4c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62b6cffe30 CR3: 0000000034c68000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>