Index: sys/netinet/tcp_input.c
===================================================================
--- sys/netinet/tcp_input.c
+++ sys/netinet/tcp_input.c
@@ -1408,7 +1408,10 @@
 			tcp_trace(TA_INPUT, ostate, tp,
 			    (void *)tcp_saveipgen, &tcp_savetcp, 0);
 #endif
-		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+		if (m != NULL)
+			TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+		else
+			TCP_PROBE3(debug__input, tp, th, 0);
 		tcp_dooptions(&to, optp, optlen, TO_SYN);
 #ifdef TCP_RFC7413
 		if (syncache_add(&inc, &to, th, inp, &so, m, NULL, NULL))
@@ -1456,7 +1459,11 @@
 	}
 #endif
 
-	TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);
+	if (m != NULL)
+		TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);
+	else
+		TCP_PROBE5(receive, NULL, tp, 0, tp, th);
+
 
 	/*
 	 * Segment belongs to a connection in SYN_SENT, ESTABLISHED or later
@@ -1468,7 +1475,10 @@
 	return (IPPROTO_DONE);
 
 dropwithreset:
-	TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);
+	if (m != NULL)
+		TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);
+	else
+		TCP_PROBE5(receive, NULL, tp, 0, tp, th);
 
 	if (ti_locked == TI_RLOCKED) {
 		INP_INFO_RUNLOCK(&V_tcbinfo);
@@ -1493,6 +1503,8 @@
 dropunlock:
 	if (m != NULL)
 		TCP_PROBE5(receive, NULL, tp, mtod(m, const char *), tp, th);
+	else
+		TCP_PROBE5(receive, NULL, tp, 0, tp, th);
 
 	if (ti_locked == TI_RLOCKED) {
 		INP_INFO_RUNLOCK(&V_tcbinfo);
@@ -1826,8 +1838,12 @@
 					    (void *)tcp_saveipgen,
 					    &tcp_savetcp, 0);
 #endif
-				TCP_PROBE3(debug__input, tp, th,
-					mtod(m, const char *));
+				if (m != NULL)
+					TCP_PROBE3(debug__input, tp, th,
+					    mtod(m, const char *));
+				else
+					TCP_PROBE3(debug__input, tp, th,
+					    0);
 				if (tp->snd_una == tp->snd_max)
 					tcp_timer_activate(tp, TT_REXMT, 0);
 				else if (!tcp_timer_active(tp, TT_PERSIST))
@@ -1873,7 +1889,10 @@
 				tcp_trace(TA_INPUT, ostate, tp,
 				    (void *)tcp_saveipgen, &tcp_savetcp, 0);
 #endif
-			TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+			if (m != NULL)
+				TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+			else 
+				TCP_PROBE3(debug__input, tp, th, 0);
 
 		/*
 		 * Automatic sizing of receive socket buffer.  Often the send
@@ -2034,8 +2053,12 @@
 			goto dropwithreset;
 		}
 		if ((thflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) {
-			TCP_PROBE5(connect__refused, NULL, tp,
-			    mtod(m, const char *), tp, th);
+			if (m != NULL)
+				TCP_PROBE5(connect__refused, NULL, tp,
+				    mtod(m, const char *), tp, th);
+			else
+				TCP_PROBE5(connect__refused, NULL, tp,
+				    0, tp, th);
 			tp = tcp_drop(tp, ECONNREFUSED);
 		}
 		if (thflags & TH_RST)
@@ -2087,8 +2110,12 @@
 				thflags &= ~TH_SYN;
 			} else {
 				tcp_state_change(tp, TCPS_ESTABLISHED);
-				TCP_PROBE5(connect__established, NULL, tp,
-				    mtod(m, const char *), tp, th);
+				if (m != NULL)
+					TCP_PROBE5(connect__established, NULL, tp,
+					    mtod(m, const char *), tp, th);
+				else
+					TCP_PROBE5(connect__established, NULL, tp,
+					    0, tp, th);
 				cc_conn_init(tp);
 				tcp_timer_activate(tp, TT_KEEP,
 				    TP_KEEPIDLE(tp));
@@ -2467,8 +2494,12 @@
 			tp->t_flags &= ~TF_NEEDFIN;
 		} else {
 			tcp_state_change(tp, TCPS_ESTABLISHED);
-			TCP_PROBE5(accept__established, NULL, tp,
-			    mtod(m, const char *), tp, th);
+			if (m != NULL)
+				TCP_PROBE5(accept__established, NULL, tp,
+				    mtod(m, const char *), tp, th);
+			else
+				TCP_PROBE5(accept__established, NULL, tp,
+				    0, tp, th);
 #ifdef TCP_RFC7413
 			if (tp->t_tfo_pending) {
 				tcp_fastopen_decrement_counter(tp->t_tfo_pending);
@@ -3202,7 +3233,10 @@
 		tcp_trace(TA_INPUT, ostate, tp, (void *)tcp_saveipgen,
 			  &tcp_savetcp, 0);
 #endif
-	TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	if (m != NULL)
+		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	else
+		TCP_PROBE3(debug__input, tp, th, 0);
 
 	/*
 	 * Return any desired output.
@@ -3250,7 +3284,10 @@
 		tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen,
 			  &tcp_savetcp, 0);
 #endif
-	TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	if (m != NULL)
+		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	else
+		TCP_PROBE3(debug__input, tp, th, 0);
 	if (ti_locked == TI_RLOCKED)
 		INP_INFO_RUNLOCK(&V_tcbinfo);
 	ti_locked = TI_UNLOCKED;
@@ -3291,7 +3328,10 @@
 		tcp_trace(TA_DROP, ostate, tp, (void *)tcp_saveipgen,
 			  &tcp_savetcp, 0);
 #endif
-	TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	if (m != NULL)
+		TCP_PROBE3(debug__input, tp, th, mtod(m, const char *));
+	else
+		TCP_PROBE3(debug__input, tp, th, 0);
 	if (tp != NULL)
 		INP_WUNLOCK(tp->t_inpcb);
 	m_freem(m);
Index: sys/netinet/tcp_output.c
===================================================================
--- sys/netinet/tcp_output.c
+++ sys/netinet/tcp_output.c
@@ -1339,7 +1339,10 @@
 		ipov->ih_len = save;
 	}
 #endif /* TCPDEBUG */
-	TCP_PROBE3(debug__output, tp, th, mtod(m, const char *));
+	if (m != NULL)
+		TCP_PROBE3(debug__output, tp, th, mtod(m, const char *));
+	else
+		TCP_PROBE3(debug__output, tp, th, 0);
 
 	/*
 	 * Fill in IP length and desired time to live and