cls_basic: use tcf_exts_get_net() before call_rcu()

Hold netns refcnt before call_rcu() and release it after
the tcf_exts_destroy() is done.

Note, on ->destroy() path we have to respect the return value
of tcf_exts_get_net(), on other paths it should always return
true, so we don't need to care.

Cc: Lucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
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 2017-11-06 13:47:20 -08:00 committed by David S. Miller
parent e4b95c41df
commit 0b2a59894b

View File

@ -85,16 +85,21 @@ static int basic_init(struct tcf_proto *tp)
return 0;
}
static void __basic_delete_filter(struct basic_filter *f)
{
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
tcf_exts_put_net(&f->exts);
kfree(f);
}
static void basic_delete_filter_work(struct work_struct *work)
{
struct basic_filter *f = container_of(work, struct basic_filter, work);
rtnl_lock();
tcf_exts_destroy(&f->exts);
tcf_em_tree_destroy(&f->ematches);
__basic_delete_filter(f);
rtnl_unlock();
kfree(f);
}
static void basic_delete_filter(struct rcu_head *head)
@ -113,7 +118,10 @@ static void basic_destroy(struct tcf_proto *tp)
list_for_each_entry_safe(f, n, &head->flist, link) {
list_del_rcu(&f->link);
tcf_unbind_filter(tp, &f->res);
call_rcu(&f->rcu, basic_delete_filter);
if (tcf_exts_get_net(&f->exts))
call_rcu(&f->rcu, basic_delete_filter);
else
__basic_delete_filter(f);
}
kfree_rcu(head, rcu);
}
@ -125,6 +133,7 @@ static int basic_delete(struct tcf_proto *tp, void *arg, bool *last)
list_del_rcu(&f->link);
tcf_unbind_filter(tp, &f->res);
tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, basic_delete_filter);
*last = list_empty(&head->flist);
return 0;
@ -219,6 +228,7 @@ static int basic_change(struct net *net, struct sk_buff *in_skb,
if (fold) {
list_replace_rcu(&fold->link, &fnew->link);
tcf_unbind_filter(tp, &fold->res);
tcf_exts_get_net(&fold->exts);
call_rcu(&fold->rcu, basic_delete_filter);
} else {
list_add_rcu(&fnew->link, &head->flist);