hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Costin Leau (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-9875) HDFS client requires compromising permission when running under JVM security manager
Date Thu, 03 Mar 2016 06:47:18 GMT

    [ https://issues.apache.org/jira/browse/HDFS-9875?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15177352#comment-15177352

Costin Leau commented on HDFS-9875:

1. I haven't tried {webhdfs}} simply because it is not an option; for stronger guarantees,
the code is based on {{FileContext}} and {{hdfs://}} instead of {{webhdfs://}}, even more
so since it might not be always enabled.
2. It's posted in the description link:

at java.lang.ProcessBuilder.start(ProcessBuilder.java:1016)
at org.apache.hadoop.util.Shell.runCommand(Shell.java:486)
at org.apache.hadoop.util.Shell.run(Shell.java:456)
at org.apache.hadoop.util.Shell$ShellCommandExecutor.execute(Shell.java:722)
at org.apache.hadoop.util.Shell.isSetsidSupported(Shell.java:391)
at org.apache.hadoop.util.Shell.<clinit>(Shell.java:381)

The current problematic field is [{{isSetsidAvailable}}|https://github.com/apache/hadoop/blob/0fa54d45b1cf8a29f089f64d24f35bd221b4803f/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java#L728]

> HDFS client requires compromising permission when running under JVM security manager
> ------------------------------------------------------------------------------------
>                 Key: HDFS-9875
>                 URL: https://issues.apache.org/jira/browse/HDFS-9875
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: hdfs-client, security
>    Affects Versions: 2.7.2
>         Environment: Linux
>            Reporter: Costin Leau
> HDFS _client_ requires dangerous permission, in particular _execute_ on _all files_ despite
only trying to connect to an HDFS cluster.
> A full list (for both Hadoop 1 and 2) is available here along with the place in code
where they occur.
> While it is understandable for some permissions to be used, requiring {{FilePermission
<<ALL FILES>> execute}} to simply initialize a class field [Shell|https://github.com/apache/hadoop/blob/0fa54d45b1cf8a29f089f64d24f35bd221b4803f/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Shell.java#L728]
which in the end is not used (since it's just a client) simply *compromises* the entire security
> To make matters worse, the code is executed to initialize a field so in case the permissions
is not granted, the VM fails with {{InitializationError}} which is unrecoverable.
> Ironically enough, on Windows this problem does not appear since the code simply bypasses
it and initializes the field with a fall back value ({{false}}).
> A quick fix would be to simply take into account that the JVM {{SecurityManager}} might
be active and the permission not granted or that the external process fails and use a fall
back value.
> A proper and long-term fix would be to minimize the use of permissions for hdfs client
since it is simply not required. A client should be as light as possible and not have the
server requirements leaked onto.

This message was sent by Atlassian JIRA

View raw message