diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c
index f8e3779b6986..670b8fcae969 100644
--- a/sys/kern/uipc_sockbuf.c
+++ b/sys/kern/uipc_sockbuf.c
@@ -794,8 +794,20 @@ sbappendaddr_locked_internal(struct sockbuf *sb, const struct sockaddr *asa,
 		return (0);
 	m->m_len = asa->sa_len;
 	bcopy(asa, mtod(m, caddr_t), asa->sa_len);
-	if (m0)
+	if (m0) {
 		m_clrprotoflags(m0);
+		m_tag_delete_chain(m0);
+		/*
+		 * Clear some persistent info from pkthdr.
+		 * We don't use m_demote(), because some netgraph consumers
+		 * expect M_PKTHDR presence.
+		 */
+		m0->m_pkthdr.rcvif = NULL;
+		m0->m_pkthdr.flowid = 0;
+		m0->m_pkthdr.csum_flags = 0;
+		m0->m_pkthdr.fibnum = 0;
+		m0->m_pkthdr.rsstype = 0;
+	}
 	if (ctrl_last)
 		ctrl_last->m_next = m0;	/* concatenate data to control */
 	else
diff --git a/sys/netinet/udp_usrreq.c b/sys/netinet/udp_usrreq.c
index abad94d98c71..f7507dc13811 100644
--- a/sys/netinet/udp_usrreq.c
+++ b/sys/netinet/udp_usrreq.c
@@ -372,9 +372,6 @@ udp_append(struct inpcb *inp, struct ip *ip, struct mbuf *n, int off,
 		append_sa = (struct sockaddr *)&udp_in[0];
 	m_adj(n, off);
 
-	/* Clear any h/w csum flags as they are no longer valid. */
-	n->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_IP_VALID);
-
 	so = inp->inp_socket;
 	SOCKBUF_LOCK(&so->so_rcv);
 	if (sbappendaddr_locked(&so->so_rcv, append_sa, n, opts) == 0) {
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 2572ede205c8..15d0f010254e 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -187,9 +187,6 @@ udp6_append(struct inpcb *inp, struct mbuf *n, int off,
 	}
 	m_adj(n, off + sizeof(struct udphdr));
 
-	/* Clear any h/w csum flags as they are no longer valid. */
-	n->m_pkthdr.csum_flags &= ~CSUM_DATA_VALID;
-
 	so = inp->inp_socket;
 	SOCKBUF_LOCK(&so->so_rcv);
 	if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&fromsa[0], n,