assert "refs != ~NUM" failed in multico

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f3d8a5574675 vmd(8): guard firmware config system state wi..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=134e86b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=c791dce2ab1a2127f65b

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9e92bd8f250c/disk-f3d8a557.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/976915bc46da/bsd-f3d8a557.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/42456a3ba360/kernel-f3d8a557.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c791dc...@syzkaller.appspotmail.com

panic: kernel diagnostic assertion "refs != ~0" failed: file "/syzkaller/managers/multico


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