cls_flower: 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_flower.c b/net/sched/cls_flower.c
index 5b5722c..7a838d1 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -218,13 +218,19 @@
return 0;
}
+static void __fl_destroy_filter(struct cls_fl_filter *f)
+{
+ tcf_exts_destroy(&f->exts);
+ tcf_exts_put_net(&f->exts);
+ kfree(f);
+}
+
static void fl_destroy_filter_work(struct work_struct *work)
{
struct cls_fl_filter *f = container_of(work, struct cls_fl_filter, work);
rtnl_lock();
- tcf_exts_destroy(&f->exts);
- kfree(f);
+ __fl_destroy_filter(f);
rtnl_unlock();
}
@@ -318,7 +324,10 @@
if (!tc_skip_hw(f->flags))
fl_hw_destroy_filter(tp, f);
tcf_unbind_filter(tp, &f->res);
- call_rcu(&f->rcu, fl_destroy_filter);
+ if (tcf_exts_get_net(&f->exts))
+ call_rcu(&f->rcu, fl_destroy_filter);
+ else
+ __fl_destroy_filter(f);
}
static void fl_destroy_sleepable(struct work_struct *work)
@@ -988,6 +997,7 @@
idr_replace_ext(&head->handle_idr, fnew, fnew->handle);
list_replace_rcu(&fold->list, &fnew->list);
tcf_unbind_filter(tp, &fold->res);
+ tcf_exts_get_net(&fold->exts);
call_rcu(&fold->rcu, fl_destroy_filter);
} else {
list_add_tail_rcu(&fnew->list, &head->filters);
