From b59388b04da1a27882ca19e0737a0903b2896740 Mon Sep 17 00:00:00 2001 From: Alan Coopersmith Date: Wed, 22 Jan 2014 23:44:46 -0800 Subject: [PATCH 05/31] 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 Signed-off-by: Alan Coopersmith Reviewed-by: Peter Hutterer Signed-off-by: Fedora X Ninjas --- 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