fix roll view log null exception (#8914)

dolphinscheduler-log-server/src/main/java/org/apache/dolphinscheduler/server/log/LoggerRequestProcessor.java

@@ -32,6 +32,8 @@ import org.apache.dolphinscheduler.remote.command.log.ViewLogResponseCommand;
 import org.apache.dolphinscheduler.remote.processor.NettyRequestProcessor;
 import org.apache.dolphinscheduler.remote.utils.Constants;
 
+import org.apache.commons.lang3.StringUtils;
+
 import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
@@ -146,6 +148,9 @@ public class LoggerRequestProcessor implements NettyRequestProcessor {
      */
     private boolean checkPathSecurity(String path) {
         String dsHome = System.getProperty("DOLPHINSCHEDULER_WORKER_HOME");
+        if (StringUtils.isBlank(dsHome)) {
+            dsHome = System.getProperty("user.dir");
+        }
         if (path.startsWith(dsHome) && !path.contains("../") && path.endsWith(".log")) {
             return true;
         }