1 files changed, 17 insertions, 7 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d10b7e0112eb..83aa604f9273 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -90,6 +90,7 @@
 #include <linux/socket.h>
 #include <linux/sockios.h>
 #include <linux/igmp.h>
+#include <linux/inetdevice.h>
 #include <linux/in.h>
 #include <linux/errno.h>
 #include <linux/timer.h>
@@ -1345,10 +1346,8 @@ csum_copy_err:
         }
         unlock_sock_fast(sk, slow);
 
-        if (noblock)
-                return -EAGAIN;
-
-        /* starting over for a new packet */
+        /* starting over for a new packet, but check if we need to yield */
+        cond_resched();
         msg->msg_flags &= ~MSG_TRUNC;
         goto try_again;
 }
@@ -1962,6 +1961,7 @@ void udp_v4_early_demux(struct sk_buff *skb)
         struct sock *sk;
         struct dst_entry *dst;
         int dif = skb->dev->ifindex;
+        int ours;
 
         /* validate the packet */
         if (!pskb_may_pull(skb, skb_transport_offset(skb) + sizeof(struct udphdr)))
@@ -1971,14 +1971,24 @@ void udp_v4_early_demux(struct sk_buff *skb)
         uh = udp_hdr(skb);
 
         if (skb->pkt_type == PACKET_BROADCAST ||
-            skb->pkt_type == PACKET_MULTICAST)
+            skb->pkt_type == PACKET_MULTICAST) {
+                struct in_device *in_dev = __in_dev_get_rcu(skb->dev);
+
+                if (!in_dev)
+                        return;
+
+                ours = ip_check_mc_rcu(in_dev, iph->daddr, iph->saddr,
+                                       iph->protocol);
+                if (!ours)
+                        return;
                 sk = __udp4_lib_mcast_demux_lookup(net, uh->dest, iph->daddr,
                                                    uh->source, iph->saddr, dif);
-        else if (skb->pkt_type == PACKET_HOST)
+        } else if (skb->pkt_type == PACKET_HOST) {
                 sk = __udp4_lib_demux_lookup(net, uh->dest, iph->daddr,
                                              uh->source, iph->saddr, dif);
-        else
+        } else {
                 return;
+        }
 
         if (!sk)
                 return;