From c578408c1fd4db09e4e3173f8a9e65c81cc187c1 Mon Sep 17 00:00:00 2001
From: Alan Coopersmith <alan.coopersmith@oracle.com>
Date: Fri, 25 Apr 2014 23:02:42 -0700
Subject: [PATCH 07/12] CVE-2014-0211: integer overflow in
 fs_read_extent_info()

fs_read_extent_info() parses a reply from the font server.
The reply contains a 32bit number of elements field which is used
to calculate a buffer length. There is an integer overflow in this
calculation which can lead to memory corruption.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Matthieu Herrb <matthieu@herrb.eu>
---
 src/fc/fserve.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/fc/fserve.c b/src/fc/fserve.c
index ec5336e..96abd0e 100644
--- a/src/fc/fserve.c
+++ b/src/fc/fserve.c
@@ -70,6 +70,7 @@ in this Software without prior written authorization from The Open Group.
 #include	"fservestr.h"
 #include	<X11/fonts/fontutil.h>
 #include	<errno.h>
+#include	<limits.h>
 
 #include	<time.h>
 #define Time_t time_t
@@ -1050,7 +1051,16 @@ fs_read_extent_info(FontPathElementPtr fpe, FSBlockDataPtr blockrec)
 	numInfos *= 2;
 	haveInk = TRUE;
     }
-    ci = pCI = malloc(sizeof(CharInfoRec) * numInfos);
+    if (numInfos >= (INT_MAX / sizeof(CharInfoRec))) {
+#ifdef DEBUG
+	fprintf(stderr,
+		"fsQueryXExtents16: numInfos (%d) >= %ld\n",
+		numInfos, (INT_MAX / sizeof(CharInfoRec)));
+#endif
+	pCI = NULL;
+    }
+    else
+	pCI = malloc(sizeof(CharInfoRec) * numInfos);
 
     if (!pCI)
     {
-- 
1.7.10