Description: fix denial of service via large ClientCutText message
Origin: backport, https://github.com/newsoft/libvncserver/commit/6037a9074d52b1963c97cb28ea1096c7c14cbf28

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

Index: libvncserver-0.9.9+dfsg/libvncserver/rfbserver.c
===================================================================
--- libvncserver-0.9.9+dfsg.orig/libvncserver/rfbserver.c	2012-05-04 10:19:00.000000000 -0400
+++ libvncserver-0.9.9+dfsg/libvncserver/rfbserver.c	2014-09-25 11:12:36.124058413 -0400
@@ -2457,6 +2457,11 @@
 	msg.cct.length = Swap32IfLE(msg.cct.length);
 
 	str = (char *)malloc(msg.cct.length);
+	if (str == NULL) {
+		rfbLogPerror("rfbProcessClientNormalMessage: not enough memory");
+		rfbCloseClient(cl);
+		return;
+	}
 
 	if ((n = rfbReadExact(cl, str, msg.cct.length)) <= 0) {
 	    if (n != 0)