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From:
Rafael Sadowski <rafael@sizeofvoid.org>
Subject:
relayd: check proc_compose return values
To:
tech@openbsd.org
Date:
Sat, 25 Jul 2026 21:05:33 +0200

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  • Rafael Sadowski:

    relayd: check proc_compose return values

OK?

commit d7c2b3a44c48d2759fa510be891cefd49dece2ea
Author: Rafael Sadowski <rafael@sizeofvoid.org>
Date:   Sat Jul 25 20:46:57 2026 +0200

    relayd: check proc_compose return values
    
    Fatal on config, setup, and startup imsg send failures. Inconsistent
    state means we can't recover.
    
    Warn on per-request responses and sync messages. A single dropped
    message shouldn't kill the whole process.

diff --git a/agentx_control.c b/agentx_control.c
index 7af1c0e..a6f5ef4 100644
--- a/agentx_control.c
+++ b/agentx_control.c
@@ -427,9 +427,11 @@ agentx_init(struct relayd *nenv)
 void
 agentx_nofd(struct agentx *usa, void *cookie, int close)
 {
-	if (!close)
-		proc_compose(env->sc_ps, PROC_PARENT, IMSG_AGENTXSOCK, NULL, 0);
-	else {
+	if (!close) {
+		if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_AGENTXSOCK,
+		    NULL, 0) == -1)
+			log_warn("%s: proc_compose", __func__);
+	} else {
 		sa = NULL;
 		agentx_init(env);
 		event_del(&(env->sc_agentxev));
@@ -456,7 +458,9 @@ agentx_setsock(struct relayd *lenv, enum privsep_procid id)
 		s = -1;
 	}
  done:
-	proc_compose_imsg(lenv->sc_ps, id, -1, IMSG_AGENTXSOCK, -1, s, NULL, 0);
+	if (proc_compose_imsg(lenv->sc_ps, id, -1, IMSG_AGENTXSOCK, -1, s,
+	    NULL, 0) == -1)
+		log_warn("%s: proc_compose_imsg", __func__);
 }
 
 void
@@ -485,7 +489,9 @@ void
 agentx_sock(int fd, short event, void *arg)
 {
 	if (event & EV_TIMEOUT) {
-		proc_compose(env->sc_ps, PROC_PARENT, IMSG_AGENTXSOCK, NULL, 0);
+		if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_AGENTXSOCK,
+		    NULL, 0) == -1)
+			log_warn("%s: proc_compose", __func__);
 		return;
 	}
 	if (event & EV_WRITE) {
diff --git a/config.c b/config.c
index b273fd7..b4ec0aa 100644
--- a/config.c
+++ b/config.c
@@ -230,7 +230,9 @@ config_setreset(struct relayd *env, u_int reset)
 		if ((reset & ps->ps_what[id]) == 0 ||
 		    id == privsep_process)
 			continue;
-		proc_compose(ps, id, IMSG_CTL_RESET, &reset, sizeof(reset));
+		if (proc_compose(ps, id, IMSG_CTL_RESET, &reset,
+		    sizeof(reset)) == -1)
+			fatal("%s: proc_compose", __func__);
 
 		/*
 		 * XXX Make sure that the reset message is sent
@@ -294,7 +296,9 @@ config_getcfg(struct relayd *env, struct imsg *imsg)
 	}
 
 	if (privsep_process != PROC_PARENT)
-		proc_compose(env->sc_ps, PROC_PARENT, IMSG_CFG_DONE, NULL, 0);
+		if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_CFG_DONE, NULL,
+		    0) == -1)
+			fatal("%s: proc_compose", __func__);
 
 	return (0);
 }
@@ -327,11 +331,13 @@ config_settable(struct relayd *env, struct table *tb)
 			iov[c++].iov_len = strlen(tb->sendbuf);
 		}
 
-		proc_composev(ps, id, IMSG_CFG_TABLE, iov, c);
+		if (proc_composev(ps, id, IMSG_CFG_TABLE, iov, c) == -1)
+			fatal("%s: proc_composev", __func__);
 
 		TAILQ_FOREACH(host, &tb->hosts, entry) {
-			proc_compose(ps, id, IMSG_CFG_HOST,
-			    &host->conf, sizeof(host->conf));
+			if (proc_compose(ps, id, IMSG_CFG_HOST, &host->conf,
+			    sizeof(host->conf)) == -1)
+				fatal("%s: proc_compose", __func__);
 		}
 	}
 
@@ -445,13 +451,15 @@ config_setrdr(struct relayd *env, struct rdr *rdr)
 		DPRINTF("%s: sending rdr %s to %s", __func__,
 		    rdr->conf.name, ps->ps_title[id]);
 
-		proc_compose(ps, id, IMSG_CFG_RDR,
-		    &rdr->conf, sizeof(rdr->conf));
+		if (proc_compose(ps, id, IMSG_CFG_RDR, &rdr->conf,
+		    sizeof(rdr->conf)) == -1)
+			fatal("%s: proc_compose", __func__);
 
 		TAILQ_FOREACH(virt, &rdr->virts, entry) {
 			virt->rdrid = rdr->conf.id;
-			proc_compose(ps, id, IMSG_CFG_VIRT,
-			    virt, sizeof(*virt));
+			if (proc_compose(ps, id, IMSG_CFG_VIRT, virt,
+			    sizeof(*virt)) == -1)
+				fatal("%s: proc_compose", __func__);
 		}
 	}
 
@@ -539,12 +547,14 @@ config_setrt(struct relayd *env, struct router *rt)
 		DPRINTF("%s: sending router %s to %s tbl %d", __func__,
 		    rt->rt_conf.name, ps->ps_title[id], rt->rt_conf.gwtable);
 
-		proc_compose(ps, id, IMSG_CFG_ROUTER,
-		    &rt->rt_conf, sizeof(rt->rt_conf));
+		if (proc_compose(ps, id, IMSG_CFG_ROUTER,
+		    &rt->rt_conf, sizeof(rt->rt_conf)) == -1)
+			fatal("%s: proc_compose", __func__);
 
 		TAILQ_FOREACH(nr, &rt->rt_netroutes, nr_entry) {
-			proc_compose(ps, id, IMSG_CFG_ROUTE,
-			    &nr->nr_conf, sizeof(nr->nr_conf));
+			if (proc_compose(ps, id, IMSG_CFG_ROUTE,
+			    &nr->nr_conf, sizeof(nr->nr_conf)) == -1)
+				fatal("%s: proc_compose", __func__);
 		}
 	}
 
@@ -650,7 +660,8 @@ config_setproto(struct relayd *env, struct protocol *proto)
 			iov[c++].iov_len = strlen(proto->style) + 1;
 		}
 
-		proc_composev(ps, id, IMSG_CFG_PROTO, iov, c);
+		if (proc_composev(ps, id, IMSG_CFG_PROTO, iov, c) == -1)
+			fatal("%s: proc_composev", __func__);
 	}
 
 	return (0);
@@ -701,7 +712,8 @@ config_setrule(struct relayd *env, struct protocol *proto)
 					rule->rule_ctl.kvlen[i].value = -1;
 			}
 
-			proc_composev(ps, id, IMSG_CFG_RULE, iov, c);
+			if (proc_composev(ps, id, IMSG_CFG_RULE, iov, c) == -1)
+				fatal("%s: proc_composev", __func__);
 		}
 	}
 
@@ -1012,7 +1024,9 @@ config_setrelay(struct relayd *env, struct relay *rlay)
 			iov[c].iov_base = &crt;
 			iov[c++].iov_len = sizeof(crt);
 
-			proc_composev(ps, id, IMSG_CFG_RELAY_TABLE, iov, c);
+			if (proc_composev(ps, id, IMSG_CFG_RELAY_TABLE, iov,
+			    c) == -1)
+				fatal("%s: proc_composev", __func__);
 		}
 	}
 
diff --git a/control.c b/control.c
index 1d4a3e6..3757bd0 100644
--- a/control.c
+++ b/control.c
@@ -362,8 +362,9 @@ control_dispatch_imsg(int fd, short event, void *arg)
 			proc_forward_imsg(env->sc_ps, &imsg, PROC_PARENT);
 			break;
 		case IMSG_CTL_POLL:
-			proc_compose(env->sc_ps, PROC_HCE,
-			    IMSG_CTL_POLL, NULL, 0);
+			if (proc_compose(env->sc_ps, PROC_HCE, IMSG_CTL_POLL,
+			    NULL, 0) == -1)
+				log_warn("%s: proc_compose", __func__);
 			imsg_compose_event(&c->iev, IMSG_CTL_OK,
 			    0, ps->ps_instance + 1, -1, NULL, 0);
 			break;
diff --git a/hce.c b/hce.c
index 05c1555..af4e7b0 100644
--- a/hce.c
+++ b/hce.c
@@ -136,7 +136,8 @@ hce_launch_checks(int fd, short event, void *arg)
 	/*
 	 * notify pfe checks are done and schedule next check
 	 */
-	proc_compose(env->sc_ps, PROC_PFE, IMSG_SYNC, NULL, 0);
+	if (proc_compose(env->sc_ps, PROC_PFE, IMSG_SYNC, NULL, 0) == -1)
+		log_warn("%s: proc_compose", __func__);
 	TAILQ_FOREACH(table, env->sc_tables, entry) {
 		TAILQ_FOREACH(host, &table->hosts, entry) {
 			if ((host->flags & F_CHECK_DONE) == 0)
@@ -246,7 +247,9 @@ hce_notify_done(struct host *host, enum host_error he)
 	if (msg)
 		log_debug("%s: %s (%s)", __func__, host->conf.name, msg);
 
-	proc_compose(env->sc_ps, PROC_PFE, IMSG_HOST_STATUS, &st, sizeof(st));
+	if (proc_compose(env->sc_ps, PROC_PFE, IMSG_HOST_STATUS, &st,
+	    sizeof(st)) == -1)
+		log_warn("%s: proc_compose", __func__);
 	if (host->up != host->last_up)
 		logopt = RELAYD_OPT_LOGUPDATE;
 
diff --git a/pfe.c b/pfe.c
index c66ad06..d527e3c 100644
--- a/pfe.c
+++ b/pfe.c
@@ -151,8 +151,9 @@ pfe_dispatch_hce(int fd, struct privsep_proc *p, struct imsg *imsg)
 			break;
 
 		/* Forward to relay engine(s) */
-		proc_compose(env->sc_ps, PROC_RELAY,
-		    IMSG_HOST_STATUS, &st, sizeof(st));
+		if (proc_compose(env->sc_ps, PROC_RELAY, IMSG_HOST_STATUS, &st,
+		    sizeof(st)) == -1)
+			log_warn("%s: proc_compose", __func__);
 
 		if ((table = table_find(env, host->conf.tableid)) ==
 		    NULL)
@@ -279,8 +280,9 @@ pfe_dispatch_relay(int fd, struct privsep_proc *p, struct imsg *imsg)
 			fatalx("%s: invalid relay proc", __func__);
 		if (natlook(env, &cnl) != 0)
 			cnl.in = -1;
-		proc_compose_imsg(env->sc_ps, PROC_RELAY, cnl.proc,
-		    IMSG_NATLOOK, -1, -1, &cnl, sizeof(cnl));
+		if (proc_compose_imsg(env->sc_ps, PROC_RELAY, cnl.proc,
+		    IMSG_NATLOOK, -1, -1, &cnl, sizeof(cnl)) == -1)
+			log_warn("%s: proc_compose_imsg", __func__);
 		break;
 	case IMSG_STATISTICS:
 		if (imsg_get_data(imsg, &crs, sizeof(crs)) == -1)
@@ -455,8 +457,9 @@ show_sessions(struct ctl_conn *c)
 		/*
 		 * Request all the running sessions from the process
 		 */
-		proc_compose_imsg(env->sc_ps, PROC_RELAY, proc,
-		    IMSG_CTL_SESSION, -1, -1, &cid, sizeof(cid));
+		if (proc_compose_imsg(env->sc_ps, PROC_RELAY, proc,
+		    IMSG_CTL_SESSION, -1, -1, &cid, sizeof(cid)) == -1)
+			log_warn("%s: proc_compose_imsg", __func__);
 		c->waiting++;
 	}
 }
@@ -544,12 +547,14 @@ disable_table(struct ctl_conn *c, struct ctl_id *id)
 	table->up = 0;
 	TAILQ_FOREACH(host, &table->hosts, entry)
 		host->up = HOST_UNKNOWN;
-	proc_compose(env->sc_ps, PROC_HCE, IMSG_TABLE_DISABLE,
-	    &table->conf.id, sizeof(table->conf.id));
+	if (proc_compose(env->sc_ps, PROC_HCE, IMSG_TABLE_DISABLE,
+	    &table->conf.id, sizeof(table->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	/* Forward to relay engine(s) */
-	proc_compose(env->sc_ps, PROC_RELAY, IMSG_TABLE_DISABLE,
-	    &table->conf.id, sizeof(table->conf.id));
+	if (proc_compose(env->sc_ps, PROC_RELAY, IMSG_TABLE_DISABLE,
+	    &table->conf.id, sizeof(table->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	log_debug("%s: table %d", __func__, table->conf.id);
 	pfe_sync();
@@ -580,12 +585,14 @@ enable_table(struct ctl_conn *c, struct ctl_id *id)
 	table->up = 0;
 	TAILQ_FOREACH(host, &table->hosts, entry)
 		host->up = HOST_UNKNOWN;
-	proc_compose(env->sc_ps, PROC_HCE, IMSG_TABLE_ENABLE,
-	    &table->conf.id, sizeof(table->conf.id));
+	if (proc_compose(env->sc_ps, PROC_HCE, IMSG_TABLE_ENABLE,
+	    &table->conf.id, sizeof(table->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	/* Forward to relay engine(s) */
-	proc_compose(env->sc_ps, PROC_RELAY, IMSG_TABLE_ENABLE,
-	    &table->conf.id, sizeof(table->conf.id));
+	if (proc_compose(env->sc_ps, PROC_RELAY, IMSG_TABLE_ENABLE,
+	    &table->conf.id, sizeof(table->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	log_debug("%s: table %d", __func__, table->conf.id);
 	pfe_sync();
@@ -627,12 +634,15 @@ disable_host(struct ctl_conn *c, struct ctl_id *id, struct host *host)
 	host->check_cnt = 0;
 	host->up_cnt = 0;
 
-	proc_compose(env->sc_ps, PROC_HCE, IMSG_HOST_DISABLE,
-	    &host->conf.id, sizeof(host->conf.id));
+	if (proc_compose(env->sc_ps, PROC_HCE, IMSG_HOST_DISABLE,
+	    &host->conf.id, sizeof(host->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	/* Forward to relay engine(s) */
-	proc_compose(env->sc_ps, PROC_RELAY, IMSG_HOST_DISABLE,
-	    &host->conf.id, sizeof(host->conf.id));
+	if (proc_compose(env->sc_ps, PROC_RELAY, IMSG_HOST_DISABLE,
+	    &host->conf.id, sizeof(host->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
+
 	log_debug("%s: host %d", __func__, host->conf.id);
 
 	if (!host->conf.parentid) {
@@ -680,12 +690,14 @@ enable_host(struct ctl_conn *c, struct ctl_id *id, struct host *host)
 	host->flags &= ~(F_DEL);
 	host->flags &= ~(F_ADD);
 
-	proc_compose(env->sc_ps, PROC_HCE, IMSG_HOST_ENABLE,
-	    &host->conf.id, sizeof(host->conf.id));
+	if (proc_compose(env->sc_ps, PROC_HCE, IMSG_HOST_ENABLE,
+	    &host->conf.id, sizeof(host->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	/* Forward to relay engine(s) */
-	proc_compose(env->sc_ps, PROC_RELAY, IMSG_HOST_ENABLE,
-	    &host->conf.id, sizeof(host->conf.id));
+	if (proc_compose(env->sc_ps, PROC_RELAY, IMSG_HOST_ENABLE,
+	    &host->conf.id, sizeof(host->conf.id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	log_debug("%s: host %d", __func__, host->conf.id);
 
@@ -808,8 +820,9 @@ pfe_sync(void)
 		    demote.level, table->conf.name, table->conf.demote_group);
 		(void)strlcpy(demote.group, table->conf.demote_group,
 		    sizeof(demote.group));
-		proc_compose(env->sc_ps, PROC_PARENT, IMSG_DEMOTE,
-		    &demote, sizeof(demote));
+		if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_DEMOTE,
+		    &demote, sizeof(demote)) == -1)
+			log_warn("%s: proc_compose", __func__);
 	}
 }
 
diff --git a/pfe_route.c b/pfe_route.c
index 5e0044c..aad82e4 100644
--- a/pfe_route.c
+++ b/pfe_route.c
@@ -82,8 +82,10 @@ sync_routes(struct relayd *env, struct router *rt)
 			memcpy(&crt.host, &host->conf, sizeof(host->conf));
 			memcpy(&crt.rt, &rt->rt_conf, sizeof(rt->rt_conf));
 
-			proc_compose(env->sc_ps, PROC_PARENT,
-			    IMSG_RTMSG, &crt, sizeof(crt));
+			if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_RTMSG,
+			    &crt, sizeof(crt)) == -1) {
+				log_warn("%s: proc_compose", __func__);
+			}
 		}
 	}
 }
diff --git a/relay.c b/relay.c
index 58e57b7..8469f8d 100644
--- a/relay.c
+++ b/relay.c
@@ -359,14 +359,17 @@ relay_init(struct privsep *ps, struct privsep_proc *p, void *arg)
 void
 relay_session_publish(struct rsession *s)
 {
-	proc_compose(env->sc_ps, PROC_PFE, IMSG_SESS_PUBLISH, s, sizeof(*s));
+	if (proc_compose(env->sc_ps, PROC_PFE, IMSG_SESS_PUBLISH, s,
+	    sizeof(*s)) == -1)
+		log_warn("%s: proc_compose", __func__);
 }
 
 void
 relay_session_unpublish(struct rsession *s)
 {
-	proc_compose(env->sc_ps, PROC_PFE, IMSG_SESS_UNPUBLISH,
-	    &s->se_id, sizeof(s->se_id));
+	if (proc_compose(env->sc_ps, PROC_PFE, IMSG_SESS_UNPUBLISH,
+	    &s->se_id, sizeof(s->se_id)) == -1)
+		log_warn("%s: proc_compose", __func__);
 }
 
 void
@@ -417,8 +420,9 @@ relay_statistics(int fd, short events, void *arg)
 
 		crs.id = rlay->rl_conf.id;
 		crs.proc = ps->ps_instance;
-		proc_compose(env->sc_ps, PROC_PFE, IMSG_STATISTICS,
-		    &crs, sizeof(crs));
+		if (proc_compose(env->sc_ps, PROC_PFE, IMSG_STATISTICS, &crs,
+		    sizeof(crs)) == -1)
+			log_warn("%s: proc_compose", __func__);
 
 		for (con = SPLAY_ROOT(&rlay->rl_sessions);
 		    con != NULL; con = next_con) {
@@ -1233,8 +1237,9 @@ relay_accept(int fd, short event, void *arg)
 		memcpy(&cnl->src, &con->se_in.ss, sizeof(cnl->src));
 		memcpy(&cnl->dst, &con->se_sockname, sizeof(cnl->dst));
 
-		proc_compose(env->sc_ps, PROC_PFE, IMSG_NATLOOK,
-		    cnl, sizeof(*cnl));
+		if (proc_compose(env->sc_ps, PROC_PFE, IMSG_NATLOOK,
+		    cnl, sizeof(*cnl)) == -1)
+			log_warn("%s: proc_compose", __func__);
 
 		/* Schedule timeout */
 		evtimer_set(&con->se_ev, relay_natlook, con);
@@ -1492,8 +1497,9 @@ relay_bindanyreq(struct rsession *con, in_port_t port, int proto)
 	bnd.bnd_port = port;
 	bnd.bnd_proto = proto;
 	bcopy(&con->se_in.ss, &bnd.bnd_ss, sizeof(bnd.bnd_ss));
-	proc_compose(env->sc_ps, PROC_PARENT, IMSG_BINDANY,
-	    &bnd, sizeof(bnd));
+	if (proc_compose(env->sc_ps, PROC_PARENT, IMSG_BINDANY,
+	    &bnd, sizeof(bnd)) == -1)
+		log_warn("%s: proc_compose", __func__);
 
 	/* Schedule timeout */
 	evtimer_set(&con->se_ev, relay_bindany, con);
@@ -1815,8 +1821,9 @@ relay_close(struct rsession *con, const char *msg, int err)
 
 	if (con->se_cnl != NULL) {
 #if 0
-		proc_compose_imsg(env->sc_ps, PROC_PFE, -1, IMSG_KILLSTATES, -1,
-		    cnl, sizeof(*cnl));
+		if (proc_compose_imsg(env->sc_ps, PROC_PFE, -1,
+		    IMSG_KILLSTATES, -1, cnl, sizeof(*cnl)) == -1)
+			log_warn("%s: proc_compose_imsg", __func__);
 #endif
 		free(con->se_cnl);
 	}
@@ -1965,12 +1972,14 @@ relay_dispatch_pfe(int fd, struct privsep_proc *p, struct imsg *imsg)
 			    &rlay->rl_sessions) {
 				memcpy(&se, con, sizeof(se));
 				se.se_cid = cid;
-				proc_compose(env->sc_ps, p->p_id,
-				    IMSG_CTL_SESSION, &se, sizeof(se));
+				if (proc_compose(env->sc_ps, p->p_id,
+				    IMSG_CTL_SESSION, &se, sizeof(se)) == -1)
+					log_warn("%s: proc_compose", __func__);
 			}
 		}
-		proc_compose(env->sc_ps, p->p_id, IMSG_CTL_END,
-		    &cid, sizeof(cid));
+		if (proc_compose(env->sc_ps, p->p_id, IMSG_CTL_END,
+		    &cid, sizeof(cid)) == -1)
+			log_warn("%s: proc_compose", __func__);
 		break;
 	default:
 		return (-1);
diff --git a/relay_udp.c b/relay_udp.c
index 7226861..7403fac 100644
--- a/relay_udp.c
+++ b/relay_udp.c
@@ -316,8 +316,9 @@ relay_udp_server(int fd, short sig, void *arg)
 		cnl->proto = IPPROTO_UDP;
 		bcopy(&con->se_in.ss, &cnl->src, sizeof(cnl->src));
 		bcopy(&rlay->rl_conf.ss, &cnl->dst, sizeof(cnl->dst));
-		proc_compose(env->sc_ps, PROC_PFE,
-		    IMSG_NATLOOK, cnl, sizeof(*cnl));
+		if (proc_compose(env->sc_ps, PROC_PFE, IMSG_NATLOOK, cnl,
+		    sizeof(*cnl)) == -1)
+			log_warn("%s: proc_compose", __func__);
 
 		/* Schedule timeout */
 		evtimer_set(&con->se_ev, relay_natlook, con);
diff --git a/relayd.c b/relayd.c
index b174fc8..5de0cc1 100644
--- a/relayd.c
+++ b/relayd.c
@@ -314,8 +314,9 @@ parent_configure(struct relayd *env)
 	for (id = 0; id < PROC_MAX; id++) {
 		if (id == privsep_process)
 			continue;
-		proc_compose_imsg(env->sc_ps, id, -1, IMSG_CFG_DONE, -1,
-		    -1, &env->sc_conf, sizeof(env->sc_conf));
+		if (proc_compose_imsg(env->sc_ps, id, -1, IMSG_CFG_DONE, -1,
+		    -1, &env->sc_conf, sizeof(env->sc_conf)) == -1)
+			fatal("%s: proc_compose_imsg", __func__);
 	}
 
 	ret = 0;
@@ -373,7 +374,9 @@ parent_configure_done(struct relayd *env)
 			if (id == privsep_process)
 				continue;
 
-			proc_compose(env->sc_ps, id, IMSG_CTL_START, NULL, 0);
+			if (proc_compose(env->sc_ps, id, IMSG_CTL_START, NULL,
+			    0) == -1)
+				fatal("%s: proc_compose", __func__);
 		}
 	}
 }
@@ -478,7 +481,9 @@ parent_dispatch_hce(int fd, struct privsep_proc *p, struct imsg *imsg)
 		scr.name[sizeof(scr.name) - 1] = '\0';
 		scr.path[sizeof(scr.path) - 1] = '\0';
 		scr.retval = script_exec(env, &scr);
-		proc_compose(ps, PROC_HCE, IMSG_SCRIPT, &scr, sizeof(scr));
+		if (proc_compose(ps, PROC_HCE, IMSG_SCRIPT, &scr,
+		    sizeof(scr)) == -1)
+			log_warn("%s: proc_compose", __func__);
 		break;
 	case IMSG_CFG_DONE:
 		parent_configure_done(env);
@@ -518,8 +523,9 @@ parent_dispatch_relay(int fd, struct privsep_proc *p, struct imsg *imsg)
 			/* NOTREACHED */
 		}
 		s = bindany(&bnd);
-		proc_compose_imsg(ps, PROC_RELAY, bnd.bnd_proc,
-		    IMSG_BINDANY, -1, s, &bnd.bnd_id, sizeof(bnd.bnd_id));
+		if (proc_compose_imsg(ps, PROC_RELAY, bnd.bnd_proc,
+		    IMSG_BINDANY, -1, s, &bnd.bnd_id, sizeof(bnd.bnd_id)) == -1)
+			log_warn("%s: proc_compose_imsg", __func__);
 		break;
 	case IMSG_CFG_DONE:
 		parent_configure_done(env);
@@ -1931,8 +1937,9 @@ parent_tls_ticket_rekey(int fd, short events, void *arg)
 	key.tt_keyrev = arc4random();
 	arc4random_buf(key.tt_key, sizeof(key.tt_key));
 
-	proc_compose_imsg(env->sc_ps, PROC_RELAY, -1, IMSG_TLSTICKET_REKEY,
-	    -1, -1, &key, sizeof(key));
+	if (proc_compose_imsg(env->sc_ps, PROC_RELAY, -1, IMSG_TLSTICKET_REKEY,
+	    -1, -1, &key, sizeof(key)) == -1)
+		log_warn("%s: proc_compose_imsg", __func__);
 
 	evtimer_set(&rekeyev, parent_tls_ticket_rekey, env);
 	timerclear(&tv);