Improve the error handling in generating ASCONF chunks.

In case of errors, the cleanup was not consistent.
Thanks to Felix Weinrank for fuzzing the userland stack and making
me aware of the issue.

MFC after:		1 week

2 files changed, 74 insertions, 98 deletions

diff --git a/sys/netinet/sctp_asconf.c b/sys/netinet/sctp_asconf.c
index 812837ac565c..7258a0822956 100644
--- a/sys/netinet/sctp_asconf.c
+++ b/sys/netinet/sctp_asconf.c
@@ -2587,14 +2587,14 @@ sctp_compose_asconf(struct sctp_tcb *stcb, int *retlen, int addr_locked)
 	if (m_asconf_chk == NULL) {
 		/* no mbuf's */
 		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "compose_asconf: couldn't get chunk mbuf!\n");
+		    "sctp_compose_asconf: couldn't get chunk mbuf!\n");
 		return (NULL);
 	}
 	m_asconf = sctp_get_mbuf_for_msg(MCLBYTES, 0, M_NOWAIT, 1, MT_DATA);
 	if (m_asconf == NULL) {
 		/* no mbuf's */
 		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "compose_asconf: couldn't get mbuf!\n");
+		    "sctp_compose_asconf: couldn't get mbuf!\n");
 		sctp_m_freem(m_asconf_chk);
 		return (NULL);
 	}
@@ -2719,10 +2719,12 @@ sctp_compose_asconf(struct sctp_tcb *stcb, int *retlen, int addr_locked)
 				break;
 #endif
 			default:
-				p_size = 0;
-				addr_size = 0;
-				addr_ptr = NULL;
-				break;
+				SCTPDBG(SCTP_DEBUG_ASCONF1,
+				    "sctp_compose_asconf: no usable lookup addr (family = %d)!\n",
+				    found_addr->sa_family);
+				sctp_m_freem(m_asconf_chk);
+				sctp_m_freem(m_asconf);
+				return (NULL);
 			}
 			lookup->ph.param_length = htons(SCTP_SIZE32(p_size));
 			memcpy(lookup->addr, addr_ptr, addr_size);
@@ -2730,12 +2732,10 @@ sctp_compose_asconf(struct sctp_tcb *stcb, int *retlen, int addr_locked)
 		} else {
 			/* uh oh... don't have any address?? */
 			SCTPDBG(SCTP_DEBUG_ASCONF1,
-			    "compose_asconf: no lookup addr!\n");
-			/* XXX for now, we send a IPv4 address of 0.0.0.0 */
-			lookup->ph.param_type = htons(SCTP_IPV4_ADDRESS);
-			lookup->ph.param_length = htons(SCTP_SIZE32(sizeof(struct sctp_ipv4addr_param)));
-			memset(lookup->addr, 0, sizeof(struct in_addr));
-			SCTP_BUF_LEN(m_asconf_chk) += SCTP_SIZE32(sizeof(struct sctp_ipv4addr_param));
+			    "sctp_compose_asconf: no lookup addr!\n");
+			sctp_m_freem(m_asconf_chk);
+			sctp_m_freem(m_asconf);
+			return (NULL);
 		}
 	}
 	/* chain it all together */
@@ -3261,10 +3261,9 @@ sctp_addr_mgmt_ep_sa(struct sctp_inpcb *inp, struct sockaddr *sa,
 }
 
 void
-sctp_asconf_send_nat_state_update(struct sctp_tcb *stcb,
-    struct sctp_nets *net)
+sctp_asconf_send_nat_state_update(struct sctp_tcb *stcb, struct sctp_nets *net)
 {
-	struct sctp_asconf_addr *aa;
+	struct sctp_asconf_addr *aa_vtag, *aa_add, *aa_del;
 	struct sctp_ifa *sctp_ifap;
 	struct sctp_asconf_tag_param *vtag;
 #ifdef INET
@@ -3273,6 +3272,7 @@ sctp_asconf_send_nat_state_update(struct sctp_tcb *stcb,
 #ifdef INET6
 	struct sockaddr_in6 *to6;
 #endif
+
 	if (net == NULL) {
 		SCTPDBG(SCTP_DEBUG_ASCONF1, "sctp_asconf_send_nat_state_update: Missing net\n");
 		return;
@@ -3282,105 +3282,81 @@ sctp_asconf_send_nat_state_update(struct sctp_tcb *stcb,
 		return;
 	}
 	/*
-	 * Need to have in the asconf: - vtagparam(my_vtag/peer_vtag) -
-	 * add(0.0.0.0) - del(0.0.0.0) - Any global addresses add(addr)
+	 * Need to have in the ASCONF: - VTAG(my_vtag/peer_vtag) -
+	 * ADD(wildcard) - DEL(wildcard) - ADD(Any global addresses)
 	 */
-	SCTP_MALLOC(aa, struct sctp_asconf_addr *, sizeof(*aa),
-	    SCTP_M_ASC_ADDR);
-	if (aa == NULL) {
-		/* didn't get memory */
-		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "sctp_asconf_send_nat_state_update: failed to get memory!\n");
+	SCTP_MALLOC(aa_vtag, struct sctp_asconf_addr *, sizeof(struct sctp_asconf_addr), SCTP_M_ASC_ADDR);
+	SCTP_MALLOC(aa_add, struct sctp_asconf_addr *, sizeof(struct sctp_asconf_addr), SCTP_M_ASC_ADDR);
+	SCTP_MALLOC(aa_del, struct sctp_asconf_addr *, sizeof(struct sctp_asconf_addr), SCTP_M_ASC_ADDR);
+
+	if ((aa_vtag == NULL) || (aa_add == NULL) || (aa_del == NULL)) {
+		/* Didn't get memory */
+		SCTPDBG(SCTP_DEBUG_ASCONF1, "sctp_asconf_send_nat_state_update: failed to get memory!\n");
+out:
+		if (aa_vtag != NULL) {
+			SCTP_FREE(aa_vtag, SCTP_M_ASC_ADDR);
+		}
+		if (aa_add != NULL) {
+			SCTP_FREE(aa_add, SCTP_M_ASC_ADDR);
+		}
+		if (aa_del != NULL) {
+			SCTP_FREE(aa_del, SCTP_M_ASC_ADDR);
+		}
 		return;
 	}
-	aa->special_del = 0;
-	/* fill in asconf address parameter fields */
-	/* top level elements are "networked" during send */
-	aa->ifa = NULL;
-	aa->sent = 0;		/* clear sent flag */
-	vtag = (struct sctp_asconf_tag_param *)&aa->ap.aph;
+	memset(aa_vtag, 0, sizeof(struct sctp_asconf_addr));
+	aa_vtag->special_del = 0;
+	/* Fill in ASCONF address parameter fields. */
+	/* Top level elements are "networked" during send. */
+	aa_vtag->ifa = NULL;
+	aa_vtag->sent = 0;	/* clear sent flag */
+	vtag = (struct sctp_asconf_tag_param *)&aa_vtag->ap.aph;
 	vtag->aph.ph.param_type = SCTP_NAT_VTAGS;
 	vtag->aph.ph.param_length = sizeof(struct sctp_asconf_tag_param);
 	vtag->local_vtag = htonl(stcb->asoc.my_vtag);
 	vtag->remote_vtag = htonl(stcb->asoc.peer_vtag);
-	TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
 
-	SCTP_MALLOC(aa, struct sctp_asconf_addr *, sizeof(*aa),
-	    SCTP_M_ASC_ADDR);
-	if (aa == NULL) {
-		/* didn't get memory */
-		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "sctp_asconf_send_nat_state_update: failed to get memory!\n");
-		return;
-	}
-	memset(aa, 0, sizeof(struct sctp_asconf_addr));
-	/* fill in asconf address parameter fields */
-	/* ADD(0.0.0.0) */
+	memset(aa_add, 0, sizeof(struct sctp_asconf_addr));
+	memset(aa_del, 0, sizeof(struct sctp_asconf_addr));
 	switch (net->ro._l_addr.sa.sa_family) {
 #ifdef INET
 	case AF_INET:
-		aa->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
-		aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addrv4_param);
-		aa->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
-		aa->ap.addrp.ph.param_length = sizeof(struct sctp_ipv4addr_param);
-		/* No need to add an address, we are using 0.0.0.0 */
-		TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
+		aa_add->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
+		aa_add->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addrv4_param);
+		aa_add->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
+		aa_add->ap.addrp.ph.param_length = sizeof(struct sctp_ipv4addr_param);
+		/* No need to fill the address, we are using 0.0.0.0 */
+		aa_del->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
+		aa_del->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addrv4_param);
+		aa_del->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
+		aa_del->ap.addrp.ph.param_length = sizeof(struct sctp_ipv4addr_param);
+		/* No need to fill the address, we are using 0.0.0.0 */
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
-		aa->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
-		aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addr_param);
-		aa->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
-		aa->ap.addrp.ph.param_length = sizeof(struct sctp_ipv6addr_param);
-		/* No need to add an address, we are using 0.0.0.0 */
-		TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
+		aa_add->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
+		aa_add->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addr_param);
+		aa_add->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
+		aa_add->ap.addrp.ph.param_length = sizeof(struct sctp_ipv6addr_param);
+		/* No need to fill the address, we are using ::0 */
+		aa_del->ap.aph.ph.param_type = SCTP_DEL_IP_ADDRESS;
+		aa_del->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addr_param);
+		aa_del->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
+		aa_del->ap.addrp.ph.param_length = sizeof(struct sctp_ipv6addr_param);
+		/* No need to fill the address, we are using ::0 */
 		break;
 #endif
 	default:
 		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "sctp_asconf_send_nat_state_update: unknown address family\n");
-		SCTP_FREE(aa, SCTP_M_ASC_ADDR);
-		return;
-	}
-	SCTP_MALLOC(aa, struct sctp_asconf_addr *, sizeof(*aa),
-	    SCTP_M_ASC_ADDR);
-	if (aa == NULL) {
-		/* didn't get memory */
-		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "sctp_asconf_send_nat_state_update: failed to get memory!\n");
-		return;
-	}
-	memset(aa, 0, sizeof(struct sctp_asconf_addr));
-	/* fill in asconf address parameter fields */
-	/* ADD(0.0.0.0) */
-	switch (net->ro._l_addr.sa.sa_family) {
-#ifdef INET
-	case AF_INET:
-		aa->ap.aph.ph.param_type = SCTP_ADD_IP_ADDRESS;
-		aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addrv4_param);
-		aa->ap.addrp.ph.param_type = SCTP_IPV4_ADDRESS;
-		aa->ap.addrp.ph.param_length = sizeof(struct sctp_ipv4addr_param);
-		/* No need to add an address, we are using 0.0.0.0 */
-		TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
-		break;
-#endif
-#ifdef INET6
-	case AF_INET6:
-		aa->ap.aph.ph.param_type = SCTP_DEL_IP_ADDRESS;
-		aa->ap.aph.ph.param_length = sizeof(struct sctp_asconf_addr_param);
-		aa->ap.addrp.ph.param_type = SCTP_IPV6_ADDRESS;
-		aa->ap.addrp.ph.param_length = sizeof(struct sctp_ipv6addr_param);
-		/* No need to add an address, we are using 0.0.0.0 */
-		TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa, next);
-		break;
-#endif
-	default:
-		SCTPDBG(SCTP_DEBUG_ASCONF1,
-		    "sctp_asconf_send_nat_state_update: unknown address family\n");
-		SCTP_FREE(aa, SCTP_M_ASC_ADDR);
-		return;
+		    "sctp_asconf_send_nat_state_update: unknown address family %d\n",
+		    net->ro._l_addr.sa.sa_family);
+		goto out;
 	}
+	TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa_vtag, next);
+	TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa_add, next);
+	TAILQ_INSERT_TAIL(&stcb->asoc.asconf_queue, aa_del, next);
+
 	/* Now we must hunt the addresses and add all global addresses */
 	if (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_BOUNDALL) {
 		struct sctp_vrf *vrf = NULL;
diff --git a/sys/netinet/sctp_input.c b/sys/netinet/sctp_input.c
index 290a01a4ed2c..9cb1edba154e 100644
--- a/sys/netinet/sctp_input.c
+++ b/sys/netinet/sctp_input.c
@@ -800,13 +800,13 @@ sctp_handle_abort(struct sctp_abort_chunk *abort,
 		cause = (struct sctp_error_cause *)(abort + 1);
 		error = ntohs(cause->code);
 		if (error == SCTP_CAUSE_NAT_COLLIDING_STATE) {
-			SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state abort flags:%x\n",
+			SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state, ABORT flags:%x\n",
 			    abort->ch.chunk_flags);
 			if (sctp_handle_nat_colliding_state(stcb)) {
 				return (0);
 			}
 		} else if (error == SCTP_CAUSE_NAT_MISSING_STATE) {
-			SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state abort flags:%x\n",
+			SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state, ABORT flags:%x\n",
 			    abort->ch.chunk_flags);
 			if (sctp_handle_nat_missing_state(stcb, net)) {
 				return (0);
@@ -1146,14 +1146,14 @@ sctp_handle_error(struct sctp_chunkhdr *ch,
 			    cause_code);
 			break;
 		case SCTP_CAUSE_NAT_COLLIDING_STATE:
-			SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state abort flags: %x\n",
+			SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state, ERROR flags: %x\n",
 			    ch->chunk_flags);
 			if (sctp_handle_nat_colliding_state(stcb)) {
 				return (0);
 			}
 			break;
 		case SCTP_CAUSE_NAT_MISSING_STATE:
-			SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state abort flags: %x\n",
+			SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state, ERROR flags: %x\n",
 			    ch->chunk_flags);
 			if (sctp_handle_nat_missing_state(stcb, net)) {
 				return (0);