Messages in this thread | | | Date | Wed, 13 Mar 2024 10:21:20 -1000 | From | Tejun Heo <> | Subject | Re: Bug in sysfs_break_active_protection() |
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Sorry about late reply.
On Mon, Mar 04, 2024 at 02:17:27PM -0500, Alan Stern wrote: .. > struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj, > const struct attribute *attr) > { > struct kernfs_node *kn; > > kobject_get(kobj); > kn = kernfs_find_and_get(kobj->sd, attr->name); > if (kn) > kernfs_break_active_protection(kn); > return kn; > } .. > If kn is NULL then the kobject_get(kobj) reference is never dropped. > It looks like this could happen if two processes want to unregister the > same kobject at the same time. > > Shouldn't sysfs_break_active_protection() do this? > > kobject_get(kobj); > kn = kernfs_find_and_get(kobj->sd, attr->name); > if (kn) > kernfs_break_active_protection(kn); > + else > + kobject_put(kobj); > return kn;
Yeah, I think you're right. It's an obvious ref leak. Would you mind writing up a patch?
Thank you.
-- tejun
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