[ 
https://issues.apache.org/jira/browse/HDFS-4968?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13708759#comment-13708759
 ] 

Colin Patrick McCabe commented on HDFS-4968:
--------------------------------------------

Thanks for tackling this.

I'm not sure that we should add this to {{FileContext}}.
{code}
+
+  // Configurable implementation
+  @Override
+  public void setConf(Configuration conf) {
+    this.conf = conf;
+  }
+
+  @Override
+  public Configuration getConf() {
+    return conf;
+  }
+
{code}

Unless I'm missing something, this will do nothing to change the Configuration 
set inside the AbstractFileSystem contained in {{FileContext#defaultFs}}.  So 
overall, it just seems likely to add to confusion... probably better to skip it?

It would also be nice to see a FileSystem based test case (perhaps in addition 
to the current one), since I believe that's what Hive is using, as well as many 
others who will find this feature useful.
                
> Provide configuration option for FileSystem symlink resolution
> --------------------------------------------------------------
>
>                 Key: HDFS-4968
>                 URL: https://issues.apache.org/jira/browse/HDFS-4968
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>    Affects Versions: 3.0.0, 2.2.0
>            Reporter: Andrew Wang
>            Assignee: Andrew Wang
>         Attachments: hdfs-4968-1.patch, hdfs-4968-2.patch
>
>
> With FileSystem symlink support incoming in HADOOP-8040, some clients will 
> wish to not transparently resolve symlinks. This is somewhat similar to 
> O_NOFOLLOW in open(2).
> Rationale for is for a security model where a user can invoke a third-party 
> service running as a service user to operate on the user's data. For 
> instance, users might want to use Hive to query data in their homedirs, where 
> Hive runs as the Hive user and the data is readable by the Hive user. This 
> leads to a security issue with symlinks:
> # User Mallory invokes Hive to process data files in {{/user/mallory/hive/}}
> # Hive checks permissions on the files in {{/user/mallory/hive/}} and allows 
> the query to proceed.
> # RACE: Mallory replaces the files in {{/user/mallory/hive}} with symlinks 
> that point to user Ann's Hive files in {{/user/ann/hive}}. These files aren't 
> readable by Mallory, but she can create whatever symlinks she wants in her 
> own scratch directory.
> # Hive's MR jobs happily resolve the symlinks and accesses Ann's private data.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to