1 files changed, 13 insertions, 9 deletions

diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 93b092c9a394..bca25179cdb9 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -313,6 +313,8 @@ drop:
         return true;
 }
 
+int sysctl_ip_early_demux __read_mostly = 1;
+
 static int ip_rcv_finish(struct sk_buff *skb)
 {
         const struct iphdr *iph = ip_hdr(skb);
@@ -323,16 +325,18 @@ static int ip_rcv_finish(struct sk_buff *skb)
          *      how the packet travels inside Linux networking.
          */
         if (skb_dst(skb) == NULL) {
-                const struct net_protocol *ipprot;
-                int protocol = iph->protocol;
-                int err;
+                int err = -ENOENT;
 
-                rcu_read_lock();
-                ipprot = rcu_dereference(inet_protos[protocol]);
-                err = -ENOENT;
-                if (ipprot && ipprot->early_demux)
-                        err = ipprot->early_demux(skb);
-                rcu_read_unlock();
+                if (sysctl_ip_early_demux) {
+                        const struct net_protocol *ipprot;
+                        int protocol = iph->protocol;
+
+                        rcu_read_lock();
+                        ipprot = rcu_dereference(inet_protos[protocol]);
+                        if (ipprot && ipprot->early_demux)
+                                err = ipprot->early_demux(skb);
+                        rcu_read_unlock();
+                }
 
                 if (err) {
                         err = ip_route_input_noref(skb, iph->daddr, iph->saddr,