Costin Leau created HDFS-9875:
---------------------------------
Summary: 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
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 system.
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
(v6.3.4#6332)
