kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 15730 Comm: kworker/1:3 Not tainted 5.0.0-rc8+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
kobject: 'loop3' (000000004c346ea1): kobject_uevent_env
Workqueue: events hci_uart_write_work
RIP: 0010:hci_uart_write_work+0x1b6/0x710 drivers/bluetooth/hci_ldisc.c:180
kobject: 'loop3' (000000004c346ea1): fill_kobj_path: path = '/devices/virtual/block/loop3'
Code: 0f 85 6a 04 00 00 49 8b b4 24 c8 00 00 00 4c 89 ef e8 9e 5c 53 02 89 c6 48 8b 45 d0 48 8d b8 5c 10 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 18 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1d
RSP: 0018:ffff8880a4b3fcb0 EFLAGS: 00010203
RAX: 000000000000020b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000105c
RBP: ffff8880a4b3fd30 R08: ffff88809ff84000 R09: ffff88809ff848c8
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a9425680
R13: ffff88805cb7a600 R14: ffff88809a2f4d28 R15: ffff8880a94256f0
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
kobject: 'loop4' (0000000060610673): kobject_uevent_env
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000738000 CR3: 0000000090f0d000 CR4: 00000000001406e0
Call Trace:
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2173
 worker_thread+0x98/0xe40 kernel/workqueue.c:2319
 kthread+0x357/0x430 kernel/kthread.c:246
kobject: 'loop4' (0000000060610673): fill_kobj_path: path = '/devices/virtual/block/loop4'
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 3ca2684e874bf6b9 ]---
RIP: 0010:hci_uart_write_work+0x1b6/0x710 drivers/bluetooth/hci_ldisc.c:180
Code: 0f 85 6a 04 00 00 49 8b b4 24 c8 00 00 00 4c 89 ef e8 9e 5c 53 02 89 c6 48 8b 45 d0 48 8d b8 5c 10 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 18 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1d
kobject: '(null)' (00000000c4e0373e): kobject_cleanup, parent           (null)
RSP: 0018:ffff8880a4b3fcb0 EFLAGS: 00010203
RAX: 000000000000020b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000105c
RBP: ffff8880a4b3fd30 R08: ffff88809ff84000 R09: ffff88809ff848c8
kobject: '(null)' (00000000c4e0373e): calling ktype release
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a9425680
R13: ffff88805cb7a600 R14: ffff88809a2f4d28 R15: ffff8880a94256f0
kobject: 'loop2' (00000000e0ea137e): kobject_uevent_env
FS:  0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
kobject: 'loop2' (00000000e0ea137e): fill_kobj_path: path = '/devices/virtual/block/loop2'
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f80a2f70000 CR3: 0000000090f0d000 CR4: 00000000001406e0