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>
diff --git a/net/sched/cls_basic.c b/net/sched/cls_basic.c
index f177649..e43c56d 100644
--- a/net/sched/cls_basic.c
+++ b/net/sched/cls_basic.c
@@ -85,16 +85,21 @@
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 @@
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 @@
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 @@
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);
