Index: bpf.c
===================================================================
RCS file: /cvs/src/sys/net/bpf.c,v
retrieving revision 1.203
diff -u -p -r1.203 bpf.c
--- bpf.c	21 Jan 2021 12:33:14 -0000	1.203
+++ bpf.c	21 Apr 2021 00:54:30 -0000
@@ -401,6 +401,7 @@ bpfclose(dev_t dev, int flag, int mode, 
 	bpf_wakeup(d);
 	LIST_REMOVE(d, bd_list);
 	mtx_leave(&d->bd_mtx);
+	klist_invalidate(&d->bd_sel.si_note);
 	bpf_put(d);
 
 	return (0);