Bug 783567

Summary:	tag attributes parsing throws jasper exception when EL is not allowed in certain cases
Product:	Red Hat Enterprise Linux 6	Reporter:	David Mansfield <bugzilla>
Component:	tomcat6	Assignee:	David Knox <dknox>
Status:	CLOSED ERRATA	QA Contact:	tomcat-qe
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.2	CC:	jclere, jdennis, jpechane, mhasko
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	tomcat6-6.0.24-44.el6	Doc Type:	Bug Fix
Doc Text:	JSP parsing utilizes the directive attribute 'deferredSyntaxAllowedAsLiteral' which determines if deferred statements are treated as literals. The default is false. If true, '#' will not be treated as an escape.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-06-20 14:35:50 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description David Mansfield 2012-01-20 20:47:42 UTC

Description of problem:
When a jsp tag that does not allow EL expression values (such as struts 2 tags) is used, and one of the attributes is passed a certain value (such as a backslash), the parser throws an exception of the form 

According to TLD or attribute directive in tag file, attribute value does not accept any expressions

This is a fixed uptream "major" bug described as a "nasty regression".  See:

https://issues.apache.org/bugzilla/show_bug.cgi?id=48627


Version-Release number of selected component (if applicable):
tomcat6-6.0.24-35.el6.noarch

How reproducible:
Always.

Steps to Reproduce:
1. pass an attribute value containing a backslash to a tag defined to not accept EL expressions.
2.
3.
  
Actual results:
Jaspaer exception, JSP not compiled, webapp dies.

Expected results:
Works.

Additional info:
Fixed upstream.

Comment 3 David Knox 2012-05-01 21:27:49 UTC

    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
No tech notes needed.

Comment 4 Michal Haško 2012-05-11 13:59:04 UTC

Do we have a reproducer for this bug? It would help a lot, I was trying to come up with a reproducer from the upstream bug, without much success so far.

Comment 5 David Mansfield 2012-05-11 14:35:40 UTC

using struts 2, i had this tag in the jsp:

<s:property value="myString.replaceAll('\\n','<br>')" escape="false" />

And got the error.

As a workaround, I downloaded the AttributeParser.class and Parser.class from the upstream bug report and put them in /usr/share/java/tomcat6/org/apache/jasper/compiler and it fixed the problem for the time being.

The important part of the tag def. is the       <rtexprvalue>false</rtexprvalue>.  Here is the complete def. from the tld:

Tag is defined in tld as

  <tag>
    <description><![CDATA[Print out expression which evaluates against the stack]]></description>
    <name>property</name>
    <tag-class>org.apache.struts2.views.jsp.PropertyTag</tag-class>
    <body-content>empty</body-content>
    <attribute>
      <description><![CDATA[The default value to be used if <u>value</u> attribute is null]]></description>
      <name>default</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Deprecated. Use 'escapeHtml'. Whether to escape HTML]]></description>
      <name>escape</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Whether to escape CSV (useful to escape a value for a column)]]></description>
      <name>escapeCsv</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Whether to escape HTML]]></description>
      <name>escapeHtml</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Whether to escape Javascript]]></description>
      <name>escapeJavaScript</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Whether to escape XML]]></description>
      <name>escapeXml</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <attribute>
      <description><![CDATA[Value to be displayed]]></description>
      <name>value</name>
      <required>false</required>
      <rtexprvalue>false</rtexprvalue>
    </attribute>
    <dynamic-attributes>false</dynamic-attributes>
  </tag>

Comment 6 David Knox 2012-05-29 17:05:55 UTC

    Technical note updated. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    Diffed Contents:
@@ -1 +1 @@
-No tech notes needed.+JSP parsing utilizes the directive attribute 'deferredSyntaxAllowedAsLiteral' which determines if deferred statements are treated as literals. The default is false. If true, '#' will not be treated as an escape.

Comment 9 errata-xmlrpc 2012-06-20 14:35:50 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2012-0945.html