act_ife: fix a potential use-after-free

Immediately after module_put(), user could delete this
module, so e->ops could be already freed before we call
e->ops->release().

Fix this by moving module_put() after ops->release().

Fixes: ef6980b6be ("introduce IFE action")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2018-09-03 11:08:15 -07:00 committed by David S. Miller
parent 639505d439
commit 6d784f1625

View File

@ -400,7 +400,6 @@ static void _tcf_ife_cleanup(struct tc_action *a)
struct tcf_meta_info *e, *n;
list_for_each_entry_safe(e, n, &ife->metalist, metalist) {
module_put(e->ops->owner);
list_del(&e->metalist);
if (e->metaval) {
if (e->ops->release)
@ -408,6 +407,7 @@ static void _tcf_ife_cleanup(struct tc_action *a)
else
kfree(e->metaval);
}
module_put(e->ops->owner);
kfree(e);
}
}