kern/54762: kernel assert "mi != NULL" when urndis is plugged

[alnsn%netbsd.org@localhost]

>Number:         54762
>Category:       kern
>Synopsis:       kernel assert "mi != NULL" when urndis is plugged
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Dec 14 00:25:00 +0000 2019
>Originator:     Alexander Nasonov
>Release:        NetBSD 9.99.24 amd64
>Organization:
	XMM SWAP LTD
>Environment:
	NetBSD neva 9.99.24 NetBSD 9.99.24 (GENERIC) #0: Fri Dec 13 23:34:36 GMT 2019 alnsn@lonet:/scratch/alnsn/netbsd-current/obj/sys/arch/amd64/compile/GENERIC amd64
System: NetBSD neva 9.99.24 NetBSD 9.99.24 (GENERIC) #0: Fri Dec 13 23:34:36 GMT 2019 alnsn@lonet:/scratch/alnsn/netbsd-current/obj/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	When I boot a recent current kernel with usb tethering, it reliably crashes:

	panic: kernel diagnostic assertion "mi != NULL" failed: /scratch/alnsn/netbsd-current/src/sys/dev/usb/usbnet.c", line 1191
	cpu1: Begin traceback...
	vpanic() at netbsd:vpanic+0x178
	kern_assert() at netbsd:kern_assert+0x48
	usbnet_tick_task() at netbsd:usbnet_tick_task+0x20e
	usb_task_thread() at netbsd:usb_task_thread+0x47
	cpu1: End traceback...

	Last working version was around 9.99.19-9.99.20.
>How-To-Repeat:
	Plug google pixel 3a, start booting, enable tethering, boom.
>Fix:
	Not known.