Based on the official fix (46109dfec75534fe270c0ab902576f685d5ab3a6) but
since we missed having 2b2844b10d7b7e5c97f9c667d664d9418bb7769a we are
two hunks smaller.

Index: avahi-0.6.25/avahi-core/socket.c
===================================================================
--- avahi-0.6.25.orig/avahi-core/socket.c
+++ avahi-0.6.25/avahi-core/socket.c
@@ -684,10 +684,14 @@ AvahiDnsPacket *avahi_recv_dns_packet_ip
         goto fail;
     }
 
-    if (sa.sin_addr.s_addr == INADDR_ANY) {
+    /* For corrupt packets FIONREAD returns zero size (See rhbz #607297). So
+     * fail after having read them. */
+    if (!ms)
+        goto fail;
+
+    if (sa.sin_addr.s_addr == INADDR_ANY)
         /* Linux 2.4 behaves very strangely sometimes! */
         goto fail;
-    }
 
     assert(!(msg.msg_flags & MSG_CTRUNC));
     assert(!(msg.msg_flags & MSG_TRUNC));
@@ -839,6 +843,11 @@ AvahiDnsPacket *avahi_recv_dns_packet_ip
         goto fail;
     }
 
+    /* For corrupt packets FIONREAD returns zero size (See rhbz #607297). So
+     * fail after having read them. */
+    if (!ms)
+        goto fail;
+
     assert(!(msg.msg_flags & MSG_CTRUNC));
     assert(!(msg.msg_flags & MSG_TRUNC));