kern/52895: kernel assertion failure in iwm driver (NetBSD-8 amd64)

[bsiegert%NetBSD.org@localhost]

>Number:         52895
>Category:       kern
>Synopsis:       kernel assertion failure in iwm driver (NetBSD-8 amd64)
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jan 03 19:20:00 +0000 2018
>Originator:     Benny Siegert
>Release:        NetBSD 8.0_BETA with DIAGNOSTIC option, compiled on Jan 3, 2018
>Organization:
The NetBSD Foundation
>Environment:
>Description:
See screenshot at https://twitter.com/bentsukun/status/948621036773367808.

Booting a NetBSD 8.0_BETA (amd64) kernel on an Intel NUC which has an iwm card triggers a panic due to a violated kernel assertion.

/usr/src/net/if.c, line 1819
panic: kernel diagnostic assertion "if_is_deactivated(ifp) || IFNET_LOCKED(ifp)" failed

This used to work with a kernel from a few months ago (October 2017 or so).
>How-To-Repeat:
Boot amd64 kernel (netbsd-8) on Intel hardware.
>Fix:
I strongly suspect pullup-8#456 to be the culprit, since that introduced the kassert.