Bluetooth: hci4 hardware error 0x43
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BUG: KASAN: use-after-free in hci_chan_del+0x131/0x180 net/bluetooth/hci_conn.c:1547
Read of size 8 at addr ffff8880a81f7198 by task kworker/u5:6/7915

CPU: 1 PID: 7915 Comm: kworker/u5:6 Not tainted 4.14.192-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci4 hci_error_reset
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 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_chan_del+0x131/0x180 net/bluetooth/hci_conn.c:1547
 l2cap_conn_del+0x417/0x670 net/bluetooth/l2cap_core.c:1736
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline]
 l2cap_disconn_cfm+0x6b/0x80 net/bluetooth/l2cap_core.c:7428
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1226 [inline]
 hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1376
 hci_dev_do_close+0x542/0xc50 net/bluetooth/hci_core.c:1620
 hci_error_reset+0x90/0xe0 net/bluetooth/hci_core.c:2156
 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 6393:
 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+0x7c/0x300 net/bluetooth/hci_conn.c:1532
 l2cap_conn_add.part.0+0x18/0xc20 net/bluetooth/l2cap_core.c:7056
 l2cap_conn_add net/bluetooth/l2cap_core.c:7415 [inline]
 l2cap_connect_cfm+0x1d2/0xce0 net/bluetooth/l2cap_core.c:7373
 hci_connect_cfm include/net/bluetooth/hci_core.h:1211 [inline]
 hci_le_conn_complete_evt net/bluetooth/hci_event.c:4602 [inline]
 hci_le_meta_evt+0x3288/0x3fc0 net/bluetooth/hci_event.c:5161
 hci_event_packet+0x25a7/0x7c7a net/bluetooth/hci_event.c:5416
 hci_rx_work+0x3e6/0x970 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 6393:
 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 net/bluetooth/hci_event.c:4433 [inline]
 hci_event_packet+0xeae/0x7c7a net/bluetooth/hci_event.c:5437
 hci_rx_work+0x3e6/0x970 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 ffff8880a81f7180
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 128-byte region [ffff8880a81f7180, ffff8880a81f7200)
The buggy address belongs to the page:
page:ffffea0002a07dc0 count:1 mapcount:0 mapping:ffff8880a81f7000 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff8880a81f7000 0000000000000000 0000000100000015
raw: ffffea0002a0ace0 ffffea0002a65ea0 ffff88812fe52640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a81f7080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8880a81f7100: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
>ffff8880a81f7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880a81f7200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8880a81f7280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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