checkentry(tee_tg_check) should initialize priv->oif from dev if possible. But only netdevice notifier handler can set that. Hence priv->oif is always -1 until notifier handler is called. Fixes: 22265a5c3c10 ("netfilter: xt_TEE: resolve oif using netdevice notifiers") Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx> --- net/netfilter/xt_TEE.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/netfilter/xt_TEE.c b/net/netfilter/xt_TEE.c index 673ad2099f97..1dae02a97ee3 100644 --- a/net/netfilter/xt_TEE.c +++ b/net/netfilter/xt_TEE.c @@ -104,6 +104,8 @@ static int tee_tg_check(const struct xt_tgchk_param *par) return -EINVAL; if (info->oif[0]) { + struct net_device *dev; + if (info->oif[sizeof(info->oif)-1] != '\0') return -EINVAL; @@ -115,6 +117,11 @@ static int tee_tg_check(const struct xt_tgchk_param *par) priv->oif = -1; info->priv = priv; + dev = dev_get_by_name(par->net, info->oif); + if (dev) { + priv->oif = dev->ifindex; + dev_put(dev); + } mutex_lock(&tn->lock); list_add(&priv->list, &tn->priv_list); mutex_unlock(&tn->lock); -- 2.17.1