WARNING: CPU: 0 PID: 1278 at drivers/tty/tty_ioctl.c:319 tty_set_termios+0x7a5/0x8d0 /drivers/tty/tty_ioctl.c:319
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 1278 Comm: kworker/u5:0 Not tainted 4.19.59 #32
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_power_on
Call Trace:
 __dump_stack /lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 /lib/dump_stack.c:113
 panic+0x263/0x507 /kernel/panic.c:185
kobject: 'loop4' (00000000e7b4b34f): kobject_uevent_env
 __warn.cold+0x20/0x4a /kernel/panic.c:540
 report_bug+0x263/0x2b0 /lib/bug.c:186
 fixup_bug /arch/x86/kernel/traps.c:178 [inline]
 fixup_bug /arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 /arch/x86/kernel/traps.c:296
kobject: 'loop4' (00000000e7b4b34f): fill_kobj_path: path = '/devices/virtual/block/loop4'
 do_invalid_op+0x1b/0x20 /arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 /arch/x86/entry/entry_64.S:1013
RIP: 0010:tty_set_termios+0x7a5/0x8d0 /drivers/tty/tty_ioctl.c:319
Code: 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 a3 00 00 00 45 89 a7 d0 03 00 00 e9 49 fe ff ff e8 bb 5d 05 fe <0f> 0b e9 3e f9 ff ff e8 af ce 3b fe e9 d6 fa ff ff e8 a5 ce 3b fe
RSP: 0018:ffff8880a64d7990 EFLAGS: 00010293
RAX: ffff8880a64c40c0 RBX: ffff8880a64d7a50 RCX: ffffffff8365b19d
RDX: 0000000000000000 RSI: ffffffff8365b865 RDI: 0000000000000005
RBP: ffff8880a64d7a78 R08: ffff8880a64c40c0 R09: fffffbfff15dd849
R10: fffffbfff15dd848 R11: 0000000000000003 R12: ffff8880a64d7ab8
R13: 0000000000010004 R14: 1ffff11014c9af51 R15: ffff88809994e640
 hci_uart_set_baudrate+0x157/0x1c0 /drivers/bluetooth/hci_ldisc.c:378
 hci_uart_setup+0xa2/0x490 /drivers/bluetooth/hci_ldisc.c:401
 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
Kernel Offset: disabled
Rebooting in 86400 seconds..