Fixes for NULL test for function returns such as malloc() - as reported by Coverity

server/core/config.c

@@ -410,6 +410,7 @@ SERVER			*server;
 				{
 					char *user = config_get_value(obj->parameters, "user");
 					char *auth = config_get_value(obj->parameters, "auth");
+					if (user && auth)
 						service_update(service, router, user, auth);
 					obj->element = service;
 				}

server/core/gwbitmask.c

@@ -48,8 +48,14 @@ void
 bitmask_init(GWBITMASK *bitmask)
 {
 	bitmask->length = BIT_LENGTH_INITIAL;
-	bitmask->bits = malloc(bitmask->length / 8);
+	if ((bitmask->bits = malloc(bitmask->length / 8)) == NULL)
+	{
+		bitmask->length = 0;
+	}
+	else
+	{
 		memset(bitmask->bits, 0, bitmask->length / 8);
+	}
 	spinlock_init(&bitmask->lock);
 }
 
@@ -196,9 +202,15 @@ bitmask_copy(GWBITMASK *dest, GWBITMASK *src)
 	spinlock_acquire(&dest->lock);
 	if (dest->length)
 		free(dest->bits);
-	dest->bits = malloc(src->length / 8);
+	if ((dest->bits = malloc(src->length / 8)) == NULL)
+	{
+		dest->length = 0;
+	}
+	else
+	{
 		dest->length = src->length;
 		memcpy(dest->bits, src->bits, src->length / 8);
+	}
 	spinlock_release(&dest->lock);
 	spinlock_release(&src->lock);
 }

server/modules/protocol/mysql_backend.c

@@ -564,7 +564,8 @@ static int gw_change_user(DCB *backend, SERVER *server, SESSION *in_session, GWB
 
         // allocate memory for token only if auth_token_len > 0
         if (auth_token_len) {
-                auth_token = (uint8_t *)malloc(auth_token_len);
+                if ((auth_token = (uint8_t *)malloc(auth_token_len)) == NULL)
+			return rv;
                 memcpy(auth_token, client_auth_packet, auth_token_len);
 		client_auth_packet += auth_token_len;
         }

server/modules/protocol/telnetd.c

@@ -257,6 +257,7 @@ telnetd_hangup(DCB *dcb)
  * socket for the protocol.
  *
  * @param dcb	The descriptor control block
+ * @return The number of new connections created
  */
 static int
 telnetd_accept(DCB *dcb)
@@ -275,17 +276,25 @@ int	n_connect = 0;
 		else
 		{
 			atomic_add(&dcb->stats.n_accepts, 1);
-			client = dcb_alloc();
+			if ((client = dcb_alloc()) == NULL)
+			{
+				return n_connect;
+			}
 			client->fd = so;
 			client->remote = strdup(inet_ntoa(addr.sin_addr));
 			memcpy(&client->func, &MyObject, sizeof(GWPROTOCOL));
 			client->session = session_alloc(dcb->session->service, client);
 
 			client->state = DCB_STATE_IDLE;
-			client->protocol = malloc(sizeof(TELNETD));
+			if ((client->protocol = malloc(sizeof(TELNETD))) == NULL)
+			{
+				dcb_free(client);
+				return n_connect;
+			}
 
 			if (poll_add_dcb(client) == -1)
 			{
+				dcb_free(client);
 				return n_connect;
 			}
 			n_connect++;