[jira] [Created] (OGNL-252) OgnlRuntime.invokeMethod can throw IllegalAccessException because of hash collisions

["Carlos Saona (JIRA)" <ji...@apache.org>]

Carlos Saona created OGNL-252:
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             Summary: OgnlRuntime.invokeMethod can throw IllegalAccessException because of hash collisions
                 Key: OGNL-252
                 URL: https://issues.apache.org/jira/browse/OGNL-252
             Project: Commons OGNL
          Issue Type: Bug
    Affects Versions: 3.0
            Reporter: Carlos Saona
            Priority: Critical


Using Struts 2.3.24 and OGNL 3.0.6, one of our production servers was not rendering one attribute of a specific page. It was weird because the other servers were rendering that same page OK, and all had the same software version.

Using the debugger, I found out that the problem was that OgnlRuntime.invoke method was throwing IllegalAccessException when invoking a given method by reflection. The difference between the working and non-working servers was that _methodAccessCache had different boolean values for that method. The non-working server failed to force the accessibility of the method because syncInvoke was set to false.

Inspecting the code of OgnlRuntime.invokeMethod, I saw the cache is using the hash of the method as a key, instead of the method itself. Therefore if two different methods that have different accessibility have a hash collision in the cache, OgnlRuntime.invokeMethod will throw an IllegalAccessException if the one that is accessible is cached before the one that is not.

I think this could be fixed by using the method itself as the map key, instead of its hash value. Browsing the changelog, I saw that at least since 3.0.9 IntHashMap has been replaced with ConcurrentHashMap, so the change would be quite straightforward. 

If you agree with the diagnostic, I volunteer to fork and submit a pull request.



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