batman_adv: batadv0: Interface activated: batadv_slave_1
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
Bluetooth: hci0: hardware error 0x43
==================================================================
BUG: KASAN: use-after-free in hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666
Read of size 8 at addr ffff8880a4b0e918 by task kworker/u5:1/6690

CPU: 0 PID: 6690 Comm: kworker/u5:1 Not tainted 4.19.136-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_error_reset
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 hci_chan_del+0x13e/0x180 net/bluetooth/hci_conn.c:1666
 l2cap_conn_del+0x44f/0x6b0 net/bluetooth/l2cap_core.c:1736
 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7435 [inline]
 l2cap_disconn_cfm+0x85/0xa0 net/bluetooth/l2cap_core.c:7428
 hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline]
 hci_conn_hash_flush+0x114/0x220 net/bluetooth/hci_conn.c:1495
 hci_dev_do_close+0x624/0xe70 net/bluetooth/hci_core.c:1666
 hci_error_reset+0x90/0xf0 net/bluetooth/hci_core.c:2205
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 6690:
 kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
 kmalloc include/linux/slab.h:515 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 hci_chan_create+0x8e/0x310 net/bluetooth/hci_conn.c:1651
 l2cap_conn_add.part.0+0x18/0xc40 net/bluetooth/l2cap_core.c:7056
 l2cap_conn_add net/bluetooth/l2cap_core.c:7415 [inline]
 l2cap_connect_cfm+0x236/0xe70 net/bluetooth/l2cap_core.c:7373
 hci_connect_cfm include/net/bluetooth/hci_core.h:1246 [inline]
 le_conn_complete_evt+0x111b/0x1730 net/bluetooth/hci_event.c:4928
 hci_le_enh_conn_complete_evt net/bluetooth/hci_event.c:4970 [inline]
 hci_le_meta_evt+0x738/0x39c0 net/bluetooth/hci_event.c:5649
 hci_event_packet+0x1a29/0x858f net/bluetooth/hci_event.c:5885
 hci_rx_work+0x46b/0xa90 net/bluetooth/hci_core.c:4359
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Freed by task 6690:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4755 [inline]
 hci_event_packet+0xf52/0x858f net/bluetooth/hci_event.c:5906
 hci_rx_work+0x46b/0xa90 net/bluetooth/hci_core.c:4359
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff8880a4b0e900
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
 128-byte region [ffff8880a4b0e900, ffff8880a4b0e980)
The buggy address belongs to the page:
page:ffffea000292c380 count:1 mapcount:0 mapping:ffff88812c39c640 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea0002316288 ffffea0002690288 ffff88812c39c640
raw: 0000000000000000 ffff8880a4b0e000 0000000100000015 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a4b0e800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a4b0e880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a4b0e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880a4b0e980: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8880a4b0ea00: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
==================================================================