From f5c34c4a092efd3aba7f0573d207a1aab28ec2c4 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 3 Sep 2018 11:08:15 -0700 Subject: [PATCH] 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: ef6980b6becb ("introduce IFE action") Cc: Jamal Hadi Salim Signed-off-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/act_ife.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/act_ife.c b/net/sched/act_ife.c index 20d7d36b2fc9..201e599baed9 100644 --- a/net/sched/act_ife.c +++ b/net/sched/act_ife.c @@ -393,7 +393,6 @@ 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) @@ -401,6 +400,7 @@ static void _tcf_ife_cleanup(struct tc_action *a) else kfree(e->metaval); } + module_put(e->ops->owner); kfree(e); } }