[HADOOP-12567] NPE in SaslRpcServer

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7.0, 2.7.1
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: Sergey Shelukhin
• Reporter: Sergey Shelukhin
• Created: 12/Nov/15 22:30
• Updated: 30/Aug/16 01:21
• Resolved: 18/Nov/15 00:04

Description

if (LOG.isDebugEnabled()) {
            String username =
              getIdentifier(authzid, secretManager).getUser().getUserName();
            LOG.debug("SASL server DIGEST-MD5 callback: setting "
                + "canonicalized client ID: " + username);
          }

Looking at identifier implementations, e.g. AbstractDelegationTokenIdentifier (and others), I can see that getUser method can return null. If debug logging is enabled, this NPEs.
If getUser is not expected to return NULL, it should either be checked and erred upon better here, or the error should be allowed to happen where it would otherwise happen, not in some debug log path.