m_free(9) handles NULL, no need to check for it beforehand. Seems that we missed these because of the (void) cast!
ok? Index: netinet/ip_output.c =================================================================== RCS file: /cvs/src/sys/netinet/ip_output.c,v retrieving revision 1.333 diff -u -p -r1.333 ip_output.c --- netinet/ip_output.c 19 Dec 2016 09:22:24 -0000 1.333 +++ netinet/ip_output.c 9 Jan 2017 17:51:52 -0000 @@ -1074,8 +1074,7 @@ ip_ctloutput(int op, struct socket *so, error = ENOPROTOOPT; break; } - if (m) - (void)m_free(m); + m_free(m); break; case PRCO_GETOPT: @@ -1242,15 +1241,13 @@ ip_pcbopts(struct mbuf **pcbopt, struct u_char opt; /* turn off any old options */ - if (*pcbopt) - (void)m_free(*pcbopt); + m_free(*pcbopt); *pcbopt = 0; if (m == NULL || m->m_len == 0) { /* * Only turning off any previous options. */ - if (m) - (void)m_free(m); + m_free(m); return (0); } Index: netinet/raw_ip.c =================================================================== RCS file: /cvs/src/sys/netinet/raw_ip.c,v retrieving revision 1.90 diff -u -p -r1.90 raw_ip.c --- netinet/raw_ip.c 19 Dec 2016 09:22:24 -0000 1.90 +++ netinet/raw_ip.c 9 Jan 2017 17:52:13 -0000 @@ -325,8 +325,7 @@ rip_ctloutput(int op, struct socket *so, inp->inp_flags |= INP_HDRINCL; else inp->inp_flags &= ~INP_HDRINCL; - if (*mp) - (void)m_free(*mp); + m_free(*mp); } else { *mp = m_get(M_WAIT, M_SOOPTS); (*mp)->m_len = sizeof(int); Index: netinet/tcp_input.c =================================================================== RCS file: /cvs/src/sys/netinet/tcp_input.c,v retrieving revision 1.334 diff -u -p -r1.334 tcp_input.c --- netinet/tcp_input.c 19 Dec 2016 08:36:49 -0000 1.334 +++ netinet/tcp_input.c 9 Jan 2017 17:53:03 -0000 @@ -3340,8 +3340,7 @@ syn_cache_rm(struct syn_cache *sc) void syn_cache_put(struct syn_cache *sc) { - if (sc->sc_ipopts) - (void) m_free(sc->sc_ipopts); + m_free(sc->sc_ipopts); if (sc->sc_route4.ro_rt != NULL) { rtfree(sc->sc_route4.ro_rt); sc->sc_route4.ro_rt = NULL; @@ -4035,8 +4034,7 @@ syn_cache_add(struct sockaddr *src, stru * If we were remembering a previous source route, * forget it and use the new one we've been given. */ - if (sc->sc_ipopts) - (void) m_free(sc->sc_ipopts); + m_free(sc->sc_ipopts); sc->sc_ipopts = ipopts; } sc->sc_timestamp = tb.ts_recent; @@ -4049,8 +4047,7 @@ syn_cache_add(struct sockaddr *src, stru sc = pool_get(&syn_cache_pool, PR_NOWAIT|PR_ZERO); if (sc == NULL) { - if (ipopts) - (void) m_free(ipopts); + m_free(ipopts); return (-1); } Index: netinet/tcp_subr.c =================================================================== RCS file: /cvs/src/sys/netinet/tcp_subr.c,v retrieving revision 1.157 diff -u -p -r1.157 tcp_subr.c --- netinet/tcp_subr.c 20 Dec 2016 09:57:10 -0000 1.157 +++ netinet/tcp_subr.c 9 Jan 2017 17:52:39 -0000 @@ -534,8 +534,7 @@ tcp_close(struct tcpcb *tp) p = q; } #endif - if (tp->t_template) - (void) m_free(tp->t_template); + m_free(tp->t_template); tp->t_flags |= TF_DEAD; timeout_add(&tp->t_reap_to, 0); Index: netinet/tcp_usrreq.c =================================================================== RCS file: /cvs/src/sys/netinet/tcp_usrreq.c,v retrieving revision 1.141 diff -u -p -r1.141 tcp_usrreq.c --- netinet/tcp_usrreq.c 3 Jan 2017 10:52:21 -0000 1.141 +++ netinet/tcp_usrreq.c 9 Jan 2017 17:52:28 -0000 @@ -569,8 +569,7 @@ tcp_ctloutput(int op, struct socket *so, error = ENOPROTOOPT; break; } - if (m) - (void) m_free(m); + m_free(m); break; case PRCO_GETOPT: Index: netinet6/ip6_output.c =================================================================== RCS file: /cvs/src/sys/netinet6/ip6_output.c,v retrieving revision 1.218 diff -u -p -r1.218 ip6_output.c --- netinet6/ip6_output.c 18 Nov 2016 02:53:47 -0000 1.218 +++ netinet6/ip6_output.c 9 Jan 2017 17:53:14 -0000 @@ -1414,8 +1414,7 @@ do { \ error = ENOPROTOOPT; break; } - if (m) - (void)m_free(m); + m_free(m); break; case PRCO_GETOPT: Index: netinet6/raw_ip6.c =================================================================== RCS file: /cvs/src/sys/netinet6/raw_ip6.c,v retrieving revision 1.101 diff -u -p -r1.101 raw_ip6.c --- netinet6/raw_ip6.c 22 Dec 2016 11:04:44 -0000 1.101 +++ netinet6/raw_ip6.c 9 Jan 2017 17:53:24 -0000 @@ -530,8 +530,7 @@ rip6_ctloutput(int op, struct socket *so case MRT6_DEL_MFC: if (op == PRCO_SETOPT) { error = ip6_mrouter_set(optname, so, *mp); - if (*mp) - (void)m_free(*mp); + m_free(*mp); } else if (op == PRCO_GETOPT) error = ip6_mrouter_get(optname, so, mp); else