From 6d784f1625ea68783cc1fb17de8f6cd3e1660c3f Mon Sep 17 00:00:00 2001
From: Cong Wang <xiyou.wangcong@gmail.com>
Date: Mon, 3 Sep 2018 11:08:15 -0700
Subject: [PATCH] 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: ef6980b6becb ("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>
---
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 196430aefe87..fc412769a1be 100644
--- a/net/sched/act_ife.c
+++ b/net/sched/act_ife.c
@@ -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);
}
}
--
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