Bluetooth: hci5: command 0xfc11 tx timeout
Bluetooth: hci5: Entering manufacturer mode failed (-110)
Bluetooth: hci5: Frame reassembly failed (-84)
Bluetooth: hci0: Entering manufacturer mode failed (-110)
==================================================================
BUG: KASAN: use-after-free in hci_cmd_timeout+0x1ba/0x1d0 net/bluetooth/hci_core.c:2574
Read of size 2 at addr ffff8880970b27c8 by task kworker/1:2/13226

CPU: 1 PID: 13226 Comm: kworker/1:2 Not tainted 4.19.88-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events hci_cmd_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:443
 hci_cmd_timeout+0x1ba/0x1d0 net/bluetooth/hci_core.c:2574
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 8014:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node_track_caller+0x51/0x80 mm/slab.c:3703
 __kmalloc_reserve.isra.0+0x40/0xf0 net/core/skbuff.c:137
 __alloc_skb+0x10b/0x5f0 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:995 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline]
 hci_prepare_cmd+0x30/0x230 net/bluetooth/hci_request.c:292
 hci_req_add_ev+0xb0/0x210 net/bluetooth/hci_request.c:326
 __hci_cmd_sync_ev+0xfc/0x1c0 net/bluetooth/hci_request.c:138
 __hci_cmd_sync+0x37/0x50 net/bluetooth/hci_request.c:187
 btintel_enter_mfg+0x2e/0x90 drivers/bluetooth/btintel.c:82
 ag6xx_setup+0x106/0x820 drivers/bluetooth/hci_ag6xx.c:180
 hci_uart_setup+0x1c1/0x490 drivers/bluetooth/hci_ldisc.c:431
 hci_dev_do_open+0x674/0x14a0 net/bluetooth/hci_core.c:1423
 hci_power_on+0x10d/0x580 net/bluetooth/hci_core.c:2130
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Freed by task 8014:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcf/0x220 mm/slab.c:3822
 skb_free_head+0x99/0xc0 net/core/skbuff.c:554
 skb_release_data+0x619/0x8d0 net/core/skbuff.c:574
 skb_release_all+0x4d/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 kfree_skb net/core/skbuff.c:663 [inline]
 kfree_skb+0xe8/0x390 net/core/skbuff.c:657
 hci_dev_do_open+0xd8c/0x14a0 net/bluetooth/hci_core.c:1509
 hci_power_on+0x10d/0x580 net/bluetooth/hci_core.c:2130
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

The buggy address belongs to the object at ffff8880970b27c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 8 bytes inside of
 512-byte region [ffff8880970b27c0, ffff8880970b29c0)
The buggy address belongs to the page:
page:ffffea00025c2c80 count:1 mapcount:0 mapping:ffff88812c31c940 index:0xffff8880970b2a40
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea00025868c8 ffffea00029e0308 ffff88812c31c940
raw: ffff8880970b2a40 ffff8880970b2040 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880970b2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880970b2700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8880970b2780: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                              ^
 ffff8880970b2800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880970b2880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================