--- corosync-2.3.5/exec/totemcrypto.c.orig	2015-07-01 18:15:45.000000000 +0300
+++ corosync-2.3.5/exec/totemcrypto.c	2018-04-14 11:19:20.598726242 +0300
@@ -627,6 +627,11 @@
 		unsigned char	tmp_hash[hash_len[instance->crypto_hash_type]];
 		int             datalen = *buf_len - hash_len[instance->crypto_hash_type];
 
+		if (*buf_len <= hash_len[instance->crypto_hash_type]) {
+			log_printf(instance->log_level_security, "Received message is too short...  ignoring");
+			return -1;
+		}
+
 		if (calculate_nss_hash(instance, buf, datalen, tmp_hash) < 0) {
 			return -1;
 		}
@@ -736,6 +741,12 @@
 {
 	struct crypto_config_header *cch = (struct crypto_config_header *)buf;
 
+	if (*buf_len <= sizeof(struct crypto_config_header)) {
+		log_printf(instance->log_level_security, "Received message is too short...  ignoring");
+
+		return (-1);
+	}
+
 	if (cch->crypto_cipher_type != CRYPTO_CIPHER_TYPE_2_3) {
 		log_printf(instance->log_level_security,
 			   "Incoming packet has different crypto type. Rejecting");