diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 8c1d73661cc4..c3fce36633b2 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -27,6 +27,9 @@ static LIST_HEAD(mirred_list); static DEFINE_SPINLOCK(mirred_list_lock); +#define MIRRED_RECURSION_LIMIT 4 +static DEFINE_PER_CPU(unsigned int, mirred_rec_level); + static bool tcf_mirred_is_act_redirect(int action) { return action == TCA_EGRESS_REDIR || action == TCA_INGRESS_REDIR; @@ -210,6 +213,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, struct sk_buff *skb2 = skb; bool m_mac_header_xmit; struct net_device *dev; + unsigned int rec_level; int retval, err = 0; bool use_reinsert; bool want_ingress; @@ -217,6 +221,14 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, int m_eaction; int mac_len; + rec_level = __this_cpu_inc_return(mirred_rec_level); + if (unlikely(rec_level > MIRRED_RECURSION_LIMIT)) { + net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n", + netdev_name(skb->dev)); + __this_cpu_dec(mirred_rec_level); + return TC_ACT_SHOT; + } + tcf_lastuse_update(&m->tcf_tm); bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb); @@ -278,6 +290,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, res->ingress = want_ingress; res->qstats = this_cpu_ptr(m->common.cpu_qstats); skb_tc_reinsert(skb, res); + __this_cpu_dec(mirred_rec_level); return TC_ACT_CONSUMED; } } @@ -293,6 +306,7 @@ out: if (tcf_mirred_is_act_redirect(m_eaction)) retval = TC_ACT_SHOT; } + __this_cpu_dec(mirred_rec_level); return retval; }