From 0e80157d06ab07ac4535448f84eec94c52716bb4 Mon Sep 17 00:00:00 2001

From: Alan Coopersmith <alan.coopersmith@oracle.com>

Date: Wed, 22 Jan 2014 23:44:46 -0800

Subject: [PATCH 05/33] dix: integer overflow in REQUEST_FIXED_SIZE()

 [CVE-2014-8092 4/4]

Force use of 64-bit integers when evaluating data provided by clients

in 32-bit fields which can overflow when added or multiplied during

checks.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

Signed-off-by: Fedora X Ninjas <x@fedoraproject.org>

---

 include/dix.h | 3 ++-

 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/dix.h b/include/dix.h

index fa7ccd4..7c36932 100644

--- a/include/dix.h

+++ b/include/dix.h

@@ -76,7 +76,8 @@ SOFTWARE.

 #define REQUEST_FIXED_SIZE(req, n)\

     if (((sizeof(req) >> 2) > client->req_len) || \

-        (((sizeof(req) + (n) + 3) >> 2) != client->req_len)) \

+        ((n >> 2) >= client->req_len) || \

+        ((((uint64_t) sizeof(req) + (n) + 3) >> 2) != (uint64_t) client->req_len))  \

          return(BadLength)

 #define LEGAL_NEW_RESOURCE(id,client)\

-- 

1.9.3