Memory leak in JspWriterImpl in JBoss AS 7

Question

On a customer system we have JBoss AS 7.1.3 with our app deployed. After every few days of active usage we experience OOM error.

In heap dump I can see that 42% of memory is occupied by org.apache.jasper.runtime.JspWriterImpl class:

The problem looks similar to this and this.

So the question is: how to resolve this memory leak? Unfortunately changing application server is not an option here.

Update: there are a lot of custom tags in the project, and they have code like this:

        try
        {
            JspWriter out = pageContext.getOut();
            out.print(page);
        }
        catch (Exception ex)
        {
            logger.error(ex);
        }