kern/56164: System panicked: kernel diagnostic assertion "(target->prt_class == class)" failed: file "/src/src/sys/kern/subr_psref.c", line 296 mismatched psref target class: 0x0 (ref) != 0xffffd2ef411bc940 (expected)

[nia%pkgsrc.org@localhost]

>Number:         56164
>Category:       kern
>Synopsis:       System panicked: kernel diagnostic assertion "(target->prt_class == class)" failed: file "/src/src/sys/kern/subr_psref.c", line 296 mismatched psref target class: 0x0 (ref) != 0xffffd2ef411bc940 (expected)
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed May 12 21:50:00 +0000 2021
>Originator:     nia
>Release:        current
>Organization:
>Environment:
NetBSD amnesia 9.99.82 NetBSD 9.99.82 (GENERIC) #4: Tue May 11 18:10:14 CEST 2021  nia@amnesia:/src/obj/sys/arch/amd64/compile/GENERIC amd64
>Description:
I've seen this panic semi-frequently (~twice in the past ~48 hours).
I'll attempt to get a reasonable backtrace when it happens again.
Unfortunately none of the crash dumps I have are usable.

System panicked: kernel diagnostic assertion "(target->prt_class == class)" failed: file "/src/src/sys/kern/subr_psref.c", line 296 mismatched psref target class: 0x0 (ref) != 0xffffd2ef411bc940 (expected)
>How-To-Repeat:
unknown, seems random
>Fix: