cls_u32: 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 13:47:30 -08:00 коммит произвёл David S. Miller
Родитель f2b751053e
Коммит 35c55fc156
1 изменённых файлов: 7 добавлений и 1 удалений

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@ -399,6 +399,7 @@ static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
bool free_pf)
{
tcf_exts_destroy(&n->exts);
tcf_exts_put_net(&n->exts);
if (n->ht_down)
n->ht_down->refcnt--;
#ifdef CONFIG_CLS_U32_PERF
@ -476,6 +477,7 @@ static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
RCU_INIT_POINTER(*kp, key->next);
tcf_unbind_filter(tp, &key->res);
tcf_exts_get_net(&key->exts);
call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
return 0;
}
@ -588,7 +590,10 @@ static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
rtnl_dereference(n->next));
tcf_unbind_filter(tp, &n->res);
u32_remove_hw_knode(tp, n->handle);
call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
if (tcf_exts_get_net(&n->exts))
call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
else
u32_destroy_key(n->tp, n, true);
}
}
}
@ -949,6 +954,7 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
u32_replace_knode(tp, tp_c, new);
tcf_unbind_filter(tp, &n->res);
tcf_exts_get_net(&n->exts);
call_rcu(&n->rcu, u32_delete_key_rcu);
return 0;
}