Commit 4fb15ff1 authored Sep 03, 2018 by Cong Wang Committed by Greg Kroah-Hartman Sep 15, 2018

act_ife: fix a potential use-after-free



[ Upstream commit 6d784f1625ea68783cc1fb17de8f6cd3e1660c3f ]

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: ef6980b6 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent bc71f393

net/sched/act_ife.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -395,7 +395,6 @@ static void _tcf_ife_cleanup(struct tc_action *a, int bind)
		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)
		@@ -403,6 +402,7 @@ static void _tcf_ife_cleanup(struct tc_action *a, int bind)
		else
		kfree(e->metaval);
		}
		module_put(e->ops->owner);
		kfree(e);
		}
		}