diff --git a/bluez/gattlib_connect.c b/bluez/gattlib_connect.c
index f2b57f6..e433655 100644
--- a/bluez/gattlib_connect.c
+++ b/bluez/gattlib_connect.c
@@ -342,6 +342,9 @@ gatt_connection_t *gattlib_connect_async(const char *src, const char *dst,
 	get_connection_options(options, &bt_io_sec_level, &psm, &mtu);
 
 	io_connect_arg_t* io_connect_arg = malloc(sizeof(io_connect_arg_t));
+	if (io_connect_arg == NULL) {
+		return NULL;
+	}
 	io_connect_arg->user_data = data;
 
 	if (options & GATTLIB_CONNECTION_OPTIONS_LEGACY_BDADDR_LE_PUBLIC) {
diff --git a/bluez/gattlib_discover.c b/bluez/gattlib_discover.c
index 213ff7d..86cf8a8 100644
--- a/bluez/gattlib_discover.c
+++ b/bluez/gattlib_discover.c
@@ -55,6 +55,10 @@ static void primary_all_cb(uint8_t status, GSList *services, void *user_data) {
 	// Allocate array
 	data->services_count = g_slist_length(services);
 	data->services = malloc(data->services_count * sizeof(gattlib_primary_service_t));
+	if (data->services == NULL) {
+		fprintf(stderr, "Discover all primary services failed: OutOfMemory\n");
+		goto done;
+	}
 
 	for (i = 0, l = services; l; l = l->next, i++) {
 		struct gatt_primary *prim = l->data;
@@ -118,6 +122,10 @@ static void characteristic_cb(uint8_t status, GSList *characteristics, void *use
 	// Allocate array
 	data->characteristics_count = g_slist_length(characteristics);
 	data->characteristics = malloc(data->characteristics_count * sizeof(gattlib_characteristic_t));
+	if (data->characteristics == NULL) {
+		fprintf(stderr, "Discover all characteristics failed: OutOfMemory\n");
+		goto done;
+	}
 
 	for (i = 0, l = characteristics; l; l = l->next, i++) {
 		struct gatt_char *chars = l->data;
@@ -188,6 +196,10 @@ static void char_desc_cb(guint8 status, const guint8 *pdu, guint16 plen, gpointe
 	// Allocate array
 	data->descriptors_count = list->num;
 	data->descriptors = malloc(data->descriptors_count * sizeof(gattlib_descriptor_t));
+	if (data->descriptors == NULL) {
+		fprintf(stderr, "Discover all descriptors failed: OutOfMemory\n");
+		goto done;
+	}
 
 	for (i = 0; i < list->num; i++) {
 		uint8_t *value;
@@ -228,6 +240,10 @@ static void char_desc_cb(uint8_t status, GSList *descriptors, void *user_data)
 	// Allocate array
 	data->descriptors_count = g_slist_length(descriptors);
 	data->descriptors = malloc(data->descriptors_count * sizeof(gattlib_descriptor_t));
+	if (data->descriptors == NULL) {
+		fprintf(stderr, "Discover all descriptors failed: OutOfMemory\n");
+		goto done;
+	}
 
 	for (i = 0, l = descriptors; l; l = l->next, i++) {
 		struct gatt_desc *desc = l->data;
diff --git a/dbus/gattlib.c b/dbus/gattlib.c
index 867daef..b57acd0 100644
--- a/dbus/gattlib.c
+++ b/dbus/gattlib.c
@@ -529,7 +529,12 @@ int gattlib_discover_primary(gatt_connection_t* connection, gattlib_primary_serv
 
 	*services       = primary_services;
 	*services_count = count;
-	return 0;
+
+ON_DEVICE_MANAGER_ERROR:
+	if (ret != GATTLIB_SUCCESS) {
+		free(primary_services);
+	}
+	return ret;
 }
 #endif