On Tue, Oct 25, 2022 at 03:15:49PM +0800, Yang Yingliang wrote: > Inject fault while loading module, kset_register() may fail. > If it fails, the kset.kobj.name allocated by kobject_set_name() > which must be called before a call to kset_register() may be > leaked, since refcount of kobj was set in kset_init(). > > To mitigate this, we free the name in kset_register() when an > error is encountered, i.e. when kset_register() returns an error. > > A kset may be embedded in a larger structure which may be dynamically > allocated in callers, it needs to be freed in ktype.release() or error > path in callers, in this case, we can not call kset_put() in kset_register(), > or it will cause double free, so just call kfree_const() to free the > name and set it to NULL to avoid accessing bad pointer in callers. > > With this fix, the callers don't need care about freeing the name > and may call kset_put() if kset_register() fails. > > Suggested-by: Luben Tuikov <luben.tuikov@xxxxxxx> > Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> > --- > v2 -> v3: > Update commit message and comment of kset_register(). > > v1 -> v2: > Free name inside of kset_register() instead of calling kset_put() > in drivers. Thank you for all of this, it's a much nicer and cleaner fix than forcing all callers to try to handle it instead. greg k-h
