Index: ip_output.c
===================================================================
RCS file: /cvs/src/sys/netinet/ip_output.c,v
retrieving revision 1.368
diff -u -p -r1.368 ip_output.c
--- ip_output.c	1 Mar 2021 11:05:42 -0000	1.368
+++ ip_output.c	7 Mar 2021 22:58:13 -0000
@@ -688,13 +688,11 @@ ip_fragment(struct mbuf *m, struct mbuf_
 			goto bad;
 		}
 		ml_enqueue(fml, m);
+		if ((error = m_dup_pkthdr(m, m0, M_DONTWAIT)) != 0)
+			goto bad;
 		m->m_data += max_linkhdr;
 		mhip = mtod(m, struct ip *);
 		*mhip = *ip;
-		/* we must inherit MCAST/BCAST flags, routing table and prio */
-		m->m_flags |= m0->m_flags & (M_MCAST|M_BCAST);
-		m->m_pkthdr.ph_rtableid = m0->m_pkthdr.ph_rtableid;
-		m->m_pkthdr.pf.prio = m0->m_pkthdr.pf.prio;
 		if (hlen > sizeof (struct ip)) {
 			mhlen = ip_optcopy(ip, mhip) + sizeof (struct ip);
 			mhip->ip_hl = mhlen >> 2;