[HDFS-7101] Potential null dereference in DFSck#doWork()

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.5.1
• Fix Version/s: 2.10.0, 3.2.0, 3.1.1, 2.9.2
• Labels: BB2015-05-TBR
• Hadoop Flags: Reviewed
• Assignee: skrho
• Reporter: Ted Yu
• Created: 19/Sep/14 20:01
• Updated: 12/Apr/18 09:07
• Resolved: 12/Apr/18 08:49

Description

    String lastLine = null;
    int errCode = -1;
    try {
      while ((line = input.readLine()) != null) {
...
    if (lastLine.endsWith(NamenodeFsck.HEALTHY_STATUS)) {
      errCode = 0;

If the input stream is empty, lastLine is kept null, leading to NPE.