Hello,

The 3.99.19 kernel panics by vnconfig(8).  This seems to be caused by
last kernel bump.

# vnconfig -l
vnd0: not in use
vnd1: not in use
vnd2: not in use
vnd3: not in use
uvm_fault(0xcbc89c40, 0, 1) -> 0xe
kernel: supervisor trap page fault, code=0
Stopped in pid 1427.1 (vnconfig) at     netbsd:prop_object_release+0x9: movl   0(%ecx),%edx
db> bt
prop_object_release(0,c0478b38,c0104603,0,1) at netbsd:prop_object_release+0x9
config_detach(c2b5a800,0,cd052204,1,3) at netbsd:config_detach+0x108
vnd_destroy(c2b5a800,0,cd873dfc,cd873e2c,c043a200) at netbsd:vnd_destroy+0x1d
vndclose(2903,1,2000,cbc8c528,c0439cc0) at netbsd:vndclose+0xb1
spec_close(cd873e74,10002,cd052204,c0306667,6) at netbsd:spec_close+0xb2
ufsspec_close(cd873e74,0,cd873f3c,c02dfa4b,c0439b80) at netbsd:ufsspec_close+0x23
VOP_CLOSE(cd052204,1,cd9a5d78,cbc8c528,cd052204) at netbsd:VOP_CLOSE+0x34
vn_close(cd052204,1,cd9a5d78,cbc8c528,0) at netbsd:vn_close+0x2e
vn_closefile(cc9e0f78,cbc8c528,cd873f3c,c02b448d,cd8308e4) at netbsd:vn_closefile+0x1a
closef(cc9e0f78,cbc8c528,cd873f5c,0,202) at netbsd:closef+0xd3
syscall_plain() at netbsd:syscall_plain+0x7e
--- syscall (number 6) ---
0xbbb29767:
db>

best regards.
-- 
 Kouichirou Hiratsuka
   hira@po6.nsk.ne.jp