sched/eevdf: Fix heap corruption more

Because someone is a flaming idiot... and forgot we have current as
se->on_rq but not actually in the tree itself, and walking rb_parent()
on an entry not in the tree is 'funky' and KASAN complains.

Fixes: 8dafa9d ("sched/eevdf: Fix min_deadline heap integrity")
Reported-by: [email protected]
Reported-by: Dmitry Safonov <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Dmitry Safonov <[email protected]>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218020
Link: https://lkml.kernel.org/r/CAJwJo6ZGXO07%3DQvW4fgQfbsDzQPs9xj5sAQ1zp%3DmAyPMNbHYww%40mail.gmail.com

Author: Peter Zijlstra

kernel/sched/fair.c

@@ -3657,7 +3657,8 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 		 */
 		deadline = div_s64(deadline * old_weight, weight);
 		se->deadline = se->vruntime + deadline;
-		min_deadline_cb_propagate(&se->run_node, NULL);
+		if (se != cfs_rq->curr)
+			min_deadline_cb_propagate(&se->run_node, NULL);
 	}
 
 #ifdef CONFIG_SMP