[HADOOP-11337] KeyAuthorizationKeyProvider access checks need to be done atomically

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.7.0
• Target Version/s: 2.7.0
• Assignee: Dian Fu
• Reporter: Dian Fu
• Created: 26/Nov/14 02:18
• Updated: 10/Apr/15 20:04
• Resolved: 02/Dec/14 05:23

Description

In KeyAuthorizationKeyProvider#getMetadata, if firstly call KeyAuthorizationKeyProvider#doAccessCheck to check if client has the permission to do this operation. However, if the metadata is null when KeyAuthorizationKeyProvider#doAccessCheck is called and becomes not null after KeyAuthorizationKeyProvider#doAccessCheck called, key based ACL check will be skipped. The getMetadata operation should be atomic.

  public Metadata getMetadata(String name) throws IOException {
    doAccessCheck(name, KeyOpType.READ);
    return provider.getMetadata(name);
  }

  private void doAccessCheck(String keyName, KeyOpType opType) throws
      IOException {
    Metadata metadata = provider.getMetadata(keyName);
    if (metadata != null) {
      String aclName = metadata.getAttributes().get(KEY_ACL_NAME);
      checkAccess((aclName == null) ? keyName : aclName, getUser(), opType);
    }
  }