Merge tag 'sched_ext-for-6.18-rc6-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext fix from Tejun Heo:
 "One low risk and obvious fix: scx_enable() was dereferencing an error
  pointer on helper kthread creation failure. Fixed"

* tag 'sched_ext-for-6.18-rc6-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
  sched_ext: Fix scx_enable() crash on helper kthread creation failure

Author: torvalds

kernel/sched/ext.c

@@ -4479,8 +4479,11 @@ static struct scx_sched *scx_alloc_and_add_sched(struct sched_ext_ops *ops)
 		goto err_free_gdsqs;
 
 	sch->helper = kthread_run_worker(0, "sched_ext_helper");
-	if (!sch->helper)
+	if (IS_ERR(sch->helper)) {
+		ret = PTR_ERR(sch->helper);
 		goto err_free_pcpu;
+	}
+
 	sched_set_fifo(sch->helper->task);
 
 	atomic_set(&sch->exit_kind, SCX_EXIT_NONE);