Inject fault while loading module, kset_register() may fail.
If it fails, the name allocated by kobject_set_name() which
is called before kset_register() is leaked, because refcount
of kobject is hold in kset_init().
As a kset may be embedded in a larger structure which needs
be freed in release() function or error path in callers, 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.
With this fix, the callers don't need to care about the name
freeing and call an extra kset_put() if kset_register() fails.
Suggested-by: Luben Tuikov <luben.tuikov@xxxxxxx>
Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx>
---
v1 -> v2:
Free name inside of kset_register() instead of calling kset_put()
in drivers.
---
lib/kobject.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/kobject.c b/lib/kobject.c
index a0b2dbfcfa23..3409a89c81e5 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -834,6 +834,9 @@ EXPORT_SYMBOL_GPL(kobj_sysfs_ops);
/**
* kset_register() - Initialize and add a kset.
* @k: kset.
+ *
+ * NOTE: On error, the kset.kobj.name allocated by() kobj_set_name()
+ * which is called before kset_register() in caller need be freed.
*/
int kset_register(struct kset *k)
{
@@ -844,8 +847,11 @@ int kset_register(struct kset *k)
kset_init(k);
err = kobject_add_internal(&k->kobj);
- if (err)
+ if (err) {
+ kfree_const(k->kobj.name);
+ k->kobj.name = NULL;
return err;
+ }
kobject_uevent(&k->kobj, KOBJ_ADD);
return 0;
}
--
2.25.1
