Index: linux-2.6.16/kernel/futex.c
===================================================================
--- linux-2.6.16.orig/kernel/futex.c	2006-06-09 01:15:28.000000000 +0530
+++ linux-2.6.16/kernel/futex.c	2006-06-09 01:18:07.000000000 +0530
@@ -358,14 +358,17 @@
 	if (!atomic_dec_and_test(&pi_state->refcount))
 		return;
 
-	WARN_ON(!pi_state->owner);
-	WARN_ON(!rt_mutex_is_locked(&pi_state->pi_mutex));
-
-	spin_lock_irq(&pi_state->owner->pi_lock);
-	list_del_init(&pi_state->list);
-	spin_unlock_irq(&pi_state->owner->pi_lock);
+	/*
+	 * If pi_state->owner is NULL, the owner is most probably dying
+	 * and has cleaned up the pi_state already
+	 */
+	if (pi_state->owner) {
+		spin_lock_irq(&pi_state->owner->pi_lock);
+		list_del_init(&pi_state->list);
+		spin_unlock_irq(&pi_state->owner->pi_lock);
 
-	rt_mutex_proxy_unlock(&pi_state->pi_mutex, pi_state->owner);
+		rt_mutex_proxy_unlock(&pi_state->pi_mutex, pi_state->owner);
+	}
 
 	if (current->pi_state_cache)
 		kfree(pi_state);