Re: [syzbot] Re: [syzbot] [acpi?] KASAN: slab-use-after-free Read in software_node_notify_remove

[syzbot <syzbot+2ff22910687ee0dfd48e@syzkaller.appspotmail.com>]

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Subject: Re: [syzbot] [acpi?] KASAN: slab-use-after-free Read in software_node_notify_remove
Author: lizhi.xu@windriver.com

any link create fail will not get kobject

#syz test

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index b1726a3515f6..5c78fa6ae772 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -1080,6 +1080,7 @@ void software_node_notify(struct device *dev)
 	if (!swnode)
 		return;
 
+	kobject_get(&swnode->kobj);
 	ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
 	if (ret)
 		return;
@@ -1089,8 +1090,6 @@ void software_node_notify(struct device *dev)
 		sysfs_remove_link(&dev->kobj, "software_node");
 		return;
 	}
-
-	kobject_get(&swnode->kobj);
 }
 
 void software_node_notify_remove(struct device *dev)