> Trying to use mgre(4), I found what looks like a reliable way to crash
> the kernel which might be of interest.
>
> This machine is a one-month-old-current fairly light router, with inet
> default within rdomain 1. I will upgrade to a more recent snap
> shortly.
I just upgraded to OpenBSD 6.8-current (GENERIC) #181: Mon Nov 23
20:55:15 MST 2020 and the same thing happens with vlan(4):
$ doas ifconfig vlan12 inet 192.0.2.1/24 parent vio0 vnetid 12
$ ifconfig vlan
vlan12: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
lladdr 02:00:00:ef:3d:d7
index 8 priority 0 llprio 3
encap: vnetid 12 parent vio0 txprio packet rxprio outer
groups: vlan
media: Ethernet autoselect
status: active
inet 192.0.2.1 netmask 0xffffff00 broadcast 192.0.2.255
$ doas route -T1 add 192.0.2.2/32 -link -iface vlan12
add host 192.0.2.2/32: gateway vlan12
$ route -T1 -n show -inet
Destination Gateway Flags Refs Use Mtu Prio Iface
192.0.2.2 link#8 UHLS 0 0 - 8 vlan12
$ route -n show -inet
Internet:
Destination Gateway Flags Refs Use Mtu Prio Iface
192.0.2/24 192.0.2.1 UCn 0 0 - 4 vlan12
192.0.2.1 02:00:00:ef:3d:d7 UHLl 0 0 - 1 vlan12
192.0.2.255 192.0.2.1 UHb 0 0 - 1 vlan12
$ doas ifconfig vlan12 down
$ doas ifconfig vlan12 destroy
$ route -T1 -n show -inet
Destination Gateway Flags Refs Use Mtu Prio Iface
192.0.2.2 link#8 UHLS 0 0 - 8 (null)
$ doas route -T1 del 192.0.2.2/32
login: panic: kernel diagnostic assertion "ifp != NULL" failed: file
"/usr/src/sys/net/rtsock.c", line 975
Stopped at db_enter+0x10: popq %rbp
TID PID UID PRFLAGS PFLAGS CPU COMMAND
*189431 84402 0 0x100003 0 0 route
db_enter() at db_enter+0x10
panic(ffffffff81dcc1d7) at panic+0x12a
__assert(ffffffff81e32678,ffffffff81e40e69,3cf,ffffffff81d9f5fd) at __assert+0x
2b
rtm_output(ffff800000071480,ffff80000e77ce80,ffff80000e77cdd8,40,1) at rtm_outp
ut+0x7ee
route_output(fffffd801ef36c00,fffffd801af0d698,0,0) at route_output+0x3c3
route_usrreq(fffffd801af0d698,9,fffffd801ef36c00,0,0,ffff80000e720540) at route
_usrreq+0x21a
sosend(fffffd801af0d698,0,ffff80000e77d0d8,0,0,0) at sosend+0x35b
dofilewritev(ffff80000e720540,3,ffff80000e77d0d8,0,ffff80000e77d1b0) at dofilew
ritev+0x14d
sys_write(ffff80000e720540,ffff80000e77d150,ffff80000e77d1b0) at sys_write+0x51
syscall(ffff80000e77d220) at syscall+0x315
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7ffffd35b0, count: 4
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports. Insufficient info makes it difficult to find and fix bugs.
ddb>
