diff -up rsyslog-8.2102.0/plugins/omelasticsearch/omelasticsearch.c.orig rsyslog-8.2102.0/plugins/omelasticsearch/omelasticsearch.c
--- rsyslog-8.2102.0/plugins/omelasticsearch/omelasticsearch.c.orig	2023-05-11 14:14:39.778187570 +0200
+++ rsyslog-8.2102.0/plugins/omelasticsearch/omelasticsearch.c	2023-05-11 14:15:36.254234445 +0200
@@ -232,7 +232,11 @@ static rsRetVal curlSetup(wrkrInstanceDa
 BEGINcreateInstance
 CODESTARTcreateInstance
 	pData->fdErrFile = -1;
-	pthread_mutex_init(&pData->mutErrFile, NULL);
+	if(pthread_mutex_init(&pData->mutErrFile, NULL) != 0) {
+		LogError(errno, RS_RET_ERR, "omelasticsearch: cannot create "
+			"error file mutex, failing this action");
+		ABORT_FINALIZE(RS_RET_ERR);
+	}
 	pData->caCertFile = NULL;
 	pData->myCertFile = NULL;
 	pData->myPrivKeyFile = NULL;
@@ -240,6 +244,7 @@ CODESTARTcreateInstance
 	pData->retryRulesetName = NULL;
 	pData->retryRuleset = NULL;
 	pData->rebindInterval = DEFAULT_REBIND_INTERVAL;
+finalize_it:
 ENDcreateInstance
 
 BEGINcreateWrkrInstance
@@ -2165,10 +2170,12 @@ ENDfreeCnf
 
 BEGINdoHUP
 CODESTARTdoHUP
+	pthread_mutex_lock(&pData->mutErrFile);
 	if(pData->fdErrFile != -1) {
 		close(pData->fdErrFile);
 		pData->fdErrFile = -1;
 	}
+	pthread_mutex_unlock(&pData->mutErrFile);
 ENDdoHUP