cls_fw: 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_fw.c b/net/sched/cls_fw.c
index 99183b8..7f45e5a 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -122,13 +122,19 @@
return 0;
}
+static void __fw_delete_filter(struct fw_filter *f)
+{
+ tcf_exts_destroy(&f->exts);
+ tcf_exts_put_net(&f->exts);
+ kfree(f);
+}
+
static void fw_delete_filter_work(struct work_struct *work)
{
struct fw_filter *f = container_of(work, struct fw_filter, work);
rtnl_lock();
- tcf_exts_destroy(&f->exts);
- kfree(f);
+ __fw_delete_filter(f);
rtnl_unlock();
}
@@ -154,7 +160,10 @@
RCU_INIT_POINTER(head->ht[h],
rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
- call_rcu(&f->rcu, fw_delete_filter);
+ if (tcf_exts_get_net(&f->exts))
+ call_rcu(&f->rcu, fw_delete_filter);
+ else
+ __fw_delete_filter(f);
}
}
kfree_rcu(head, rcu);
@@ -179,6 +188,7 @@
if (pfp == f) {
RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
tcf_unbind_filter(tp, &f->res);
+ tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, fw_delete_filter);
ret = 0;
break;
@@ -299,6 +309,7 @@
RCU_INIT_POINTER(fnew->next, rtnl_dereference(pfp->next));
rcu_assign_pointer(*fp, fnew);
tcf_unbind_filter(tp, &f->res);
+ tcf_exts_get_net(&f->exts);
call_rcu(&f->rcu, fw_delete_filter);
*arg = fnew;
