From 48f4bf187e958a13d57eea3f41eeab7c26c66806 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sat, 3 Jan 2015 08:46:45 -0800 Subject: dix: Allow zero-height PutImage requests (fix for X.Org's CVE-2015-3418) The length checking code validates PutImage height and byte width by making sure that byte-width >= INT32_MAX / height. If height is zero, this generates a divide by zero exception. Allow zero height requests explicitly, bypassing the INT32_MAX check. v2: backports to VcXsrv 1.15.2.x (Mike DePaulo) Signed-off-by: Keith Packard Reviewed-by: Alan Coopersmith --- xorg-server/dix/dispatch.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/xorg-server/dix/dispatch.c b/xorg-server/dix/dispatch.c index 67dbce6e1..304bee768 100644 --- a/xorg-server/dix/dispatch.c +++ b/xorg-server/dix/dispatch.c @@ -2002,7 +2002,7 @@ ProcPutImage(ClientPtr client) tmpImage = (char *) &stuff[1]; lengthProto = length; - if (lengthProto >= (INT32_MAX / stuff->height)) + if (stuff->height != 0 && lengthProto >= (INT32_MAX / stuff->height)) return BadLength; if ((bytes_to_int32(lengthProto * stuff->height) + -- cgit v1.2.3