integer overflow in XvMCListSurfaceTypes() [CVE-2013-1990 1/2]

rep.num is a CARD32 and needs to be bounds checked before multiplying
by sizeof(XvMCSurfaceInfo) to come up with the total size to allocate,
to avoid integer overflow leading to underallocation and writing data from
the network past the end of the allocated buffer.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/XvMC.c b/src/XvMC.c
index b3e97ec..5d8c2cf 100644
--- a/src/XvMC.c
+++ b/src/XvMC.c
@@ -123,8 +123,8 @@ XvMCSurfaceInfo * XvMCListSurfaceTypes(Display *dpy, XvPortID port, int *num)
     }
 
     if(rep.num > 0) {
-	surface_info =
-	    (XvMCSurfaceInfo*)Xmalloc(rep.num * sizeof(XvMCSurfaceInfo));
+        if (rep.num < (INT_MAX / sizeof(XvMCSurfaceInfo)))
+            surface_info = Xmalloc(rep.num * sizeof(XvMCSurfaceInfo));
 
         if(surface_info) {
 	    xvmcSurfaceInfo sinfo;