I didn't found the answer, that's why I post here.
Not sure if this is the solution to your problem, but try to use
a javax.ejb.MessageDrivenContext.getUserTransaction().setTransactionTimeout() call within your onMessage() method to override the default transaction timeout initialized by the JBoss transaction manager.
Can I modify this value in the jboss configuration without
changing the java code ?
I'm going to try this.