Index: if.c
===================================================================
RCS file: /cvs/src/sys/net/if.c,v
retrieving revision 1.602
diff -u -p -r1.602 if.c
--- if.c	11 Apr 2020 10:49:27 -0000	1.602
+++ if.c	12 Apr 2020 01:58:07 -0000
@@ -951,6 +951,9 @@ if_vinput(struct ifnet *ifp, struct mbuf
 	caddr_t if_bpf;
 #endif
 
+	/* require the same locking that if_input_process provides */
+	NET_ASSERT_LOCKED();
+
 	m->m_pkthdr.ph_ifidx = ifp->if_index;
 	m->m_pkthdr.ph_rtableid = ifp->if_rdomain;
 
Index: if_tun.c
===================================================================
RCS file: /cvs/src/sys/net/if_tun.c,v
retrieving revision 1.220
diff -u -p -r1.220 if_tun.c
--- if_tun.c	7 Apr 2020 13:27:52 -0000	1.220
+++ if_tun.c	12 Apr 2020 01:58:07 -0000
@@ -866,9 +866,9 @@ tun_dev_write(dev_t dev, struct uio *uio
 	if (error != 0)
 		goto drop;
 
-	NET_RLOCK();
+	NET_LOCK();
 	if_vinput(ifp, m0);
-	NET_RUNLOCK();
+	NET_UNLOCK();
 
 	tun_put(sc);
 	return (0);