Bluetooth: Unexpected start frame (len 16)
Bluetooth: Unknown LE signaling command 0x17
Bluetooth: Wrong link type (-22)
==================================================================
BUG: KASAN: use-after-free in hci_send_acl+0xcf4/0xe90 net/bluetooth/hci_core.c:3540
Read of size 8 at addr ffff8880abb60d98 by task kworker/u5:0/1676

CPU: 0 PID: 1676 Comm: kworker/u5:0 Not tainted 4.14.217-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 hci_send_acl+0xcf4/0xe90 net/bluetooth/hci_core.c:3540
 l2cap_send_cmd+0x69c/0x8d0 net/bluetooth/l2cap_core.c:877
 l2cap_le_sig_channel net/bluetooth/l2cap_core.c:5760 [inline]
 l2cap_recv_frame+0x2a3b/0x9360 net/bluetooth/l2cap_core.c:7033
 l2cap_recv_acldata+0x8f9/0xa30 net/bluetooth/l2cap_core.c:7594
 hci_acldata_packet net/bluetooth/hci_core.c:4066 [inline]
 hci_rx_work+0x403/0xb40 net/bluetooth/hci_core.c:4249
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 8054:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 hci_chan_create+0x8b/0x3a0 net/bluetooth/hci_conn.c:1549
 l2cap_conn_add.part.0+0x18/0xc30 net/bluetooth/l2cap_core.c:7062
 l2cap_conn_add include/net/bluetooth/l2cap.h:811 [inline]
 l2cap_connect_cfm+0x526/0xdb0 net/bluetooth/l2cap_core.c:7379
 hci_connect_cfm include/net/bluetooth/hci_core.h:1211 [inline]
 hci_le_conn_complete_evt net/bluetooth/hci_event.c:4606 [inline]
 hci_le_meta_evt+0x369e/0x4410 net/bluetooth/hci_event.c:5172
 hci_event_packet+0x2217/0x7510 net/bluetooth/hci_event.c:5432
 hci_rx_work+0x427/0xb40 net/bluetooth/hci_core.c:4244
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Freed by task 1676:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 hci_disconn_loglink_complete_evt.isra.0+0x1c1/0x230 net/bluetooth/hci_event.c:4437
 hci_event_packet+0x3444/0x7510 net/bluetooth/hci_event.c:5453
 hci_rx_work+0x427/0xb40 net/bluetooth/hci_core.c:4244
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

The buggy address belongs to the object at ffff8880abb60d80
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 128-byte region [ffff8880abb60d80, ffff8880abb60e00)
The buggy address belongs to the page:
page:ffffea0002aed800 count:1 mapcount:0 mapping:ffff8880abb60000 index:0xffff8880abb60c00
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880abb60000 ffff8880abb60c00 0000000100000014
raw: ffffea0002754260 ffffea00028d61e0 ffff88813fe80640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880abb60c80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880abb60d00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8880abb60d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880abb60e00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880abb60e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================