Bug 3996: Malformed DNS reply leads to crash

diff --git a/src/dns_internal.cc b/src/dns_internal.cc
index 0cc3d616267238a1514c47210961b0203c3a9048..dea61136203c41c0bbceec18b5df7e3c90639049 100644 (file)
--- a/src/dns_internal.cc
+++ b/src/dns_internal.cc
@@ -1504,6 +1504,12 @@ idnsReadVCHeader(const Comm::ConnectionPointer &conn, char *buf, size_t len, com
 
     vc->msglen = ntohs(vc->msglen);
 
+    if (!vc->msglen) {
+        if (Comm::IsConnOpen(conn))
+            conn->close();
+        return;
+    }
+
     vc->msg->init(vc->msglen, vc->msglen);
     AsyncCall::Pointer call = commCbCall(5,4, "idnsReadVC",
                                          CommIoCbPtrFun(idnsReadVC, vc));