kern/56036: kernel panic in urtwn driver

[bsiegert%gmail.com@localhost]

>Number:         56036
>Category:       kern
>Synopsis:       kernel panic in urtwn driver
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 04 20:20:00 +0000 2021
>Originator:     bsiegert%gmail.com@localhost
>Release:        NetBSD 9.99.80
>Organization:
	The NetBSD Foundation
>Environment:
System: NetBSD meguro.bentsukun.ch NetBSD 9.99.80 (SPLEEN64) #4: Sat Feb 27 21:58:36 CET 2021
Architecture: aarch64
Machine: evbarm
>Description:
In a recent -current kernel on a Pinebook Pro, I have been seeing regular
kernel panics when using an urtwn USB Wi-Fi stick.

[     3.559238] urtwn0 at uhub6 port 1
[     3.559238] urtwn0: Realtek (0x0bda) 802.11n WLAN Adapter (0x8176), rev 2.00/2.00, addr 1
[     3.569239] urtwn0: MAC/BB RTL8188CUS, RF 6052 1T1R, address a0:f3:c1:0f:44:d0
[     3.569239] urtwn0: 1 rx pipe, 2 tx pipes

The panic is:

kernel diagnostic assertion "(from->m_flags & M_PKTHDR) != 0" failed: file "/usr/src/sys/kern/uipc_mbuf.c", line 1799

Full stack trace at https://photos.app.goo.gl/a4Hgn2NdpzjAVJ8k8

>How-To-Repeat:
Use NetBSD 9.99.80 on Pinebook Pro with a TP-LINK USB Wireless adapter.
FWIW, this does not occur with a 9.99.76 snapshot.
>Fix:
n/a