File LibVNCServer-CVE-2018-20750.patch of Package LibVNCServer.27291

Index: libvncserver-LibVNCServer-0.9.10/libvncserver/rfbserver.c
===================================================================
--- libvncserver-LibVNCServer-0.9.10.orig/libvncserver/rfbserver.c	2019-02-05 14:11:27.552345876 +0100
+++ libvncserver-LibVNCServer-0.9.10/libvncserver/rfbserver.c	2019-02-05 14:19:41.526622829 +0100
@@ -87,6 +87,9 @@
 #include <time.h>
 /* PRIu32 */
 #include <inttypes.h>
+/* INT_MAX */
+#include <limits.h>
+
 
 #ifdef LIBVNCSERVER_WITH_WEBSOCKETS
 #include "rfbssl.h"
@@ -1465,8 +1468,11 @@ char *rfbProcessFileTransferReadBuffer(r
        0XFFFFFFFF, i.e. SIZE_MAX for 32-bit systems. On 64-bit systems, a length of 0XFFFFFFFF
        will safely be allocated since this check will never trigger and malloc() can digest length+1
        without problems as length is a uint32_t.
+       We also later pass length to rfbReadExact() that expects a signed int type and
+       that might wrap on platforms with a 32-bit int type if length is bigger
+       than 0X7FFFFFFF.
     */
-    if(length == SIZE_MAX) {
+    if(length == SIZE_MAX || length > INT_MAX) {
 	rfbErr("rfbProcessFileTransferReadBuffer: too big file transfer length requested: %u", (unsigned int)length);
 	rfbCloseClient(cl);
 	return NULL;