[
https://issues.apache.org/jira/browse/MAPREDUCE-1994?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12895743#action_12895743
]
Todd Lipcon commented on MAPREDUCE-1994:
----------------------------------------
Yea, sorry, HADOOP_CONF_DIR - the code is a bit messy as it actually detects
HADOOP_HOME and then appends conf/ later... working on a patch that cleans this
code up as well.
bq. It is documented to set permissions on task-controller to be as strict as
"6050 root mapred". That should avoid creating hard links to the binary, no?
I believe you're allowed to make hard links to other files regardless of their
permissions. If it were kept in a directory with strict permissions, that would
help the issue a little bit.
bq. Just curious, an example of argv[0] spoof?
perl -e 'exec { "/real/path/to/task-controller" } "fake-argv[0]", "normal",
"args", "...";'
There isn't really an obvious exploit here since task-controller is supposed to
be set with permissions so that the normal user can't run it. But if it's
misconfigured, the attacker can likely evade the check for that
misconfiguration by something like this, so it's worth fixing.
> Linux task-controller determines its own path insecurely
> --------------------------------------------------------
>
> Key: MAPREDUCE-1994
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-1994
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: security, task-controller
> Affects Versions: 0.22.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Priority: Critical
>
> The task-controller uses argv[0] to determine its own path, and then calls
> stat() on that. Instead it should stat("/proc/self/exe") directly. This is
> important since argv[0] can be spoofed to point to another program and thus
> either fool the autodetection of HADOOP_HOME or evade various permissions
> checks.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
