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authorAlan Coopersmith <alan.coopersmith@oracle.com>2013-04-12 21:44:59 -0700
committerAlan Coopersmith <alan.coopersmith@oracle.com>2013-05-04 21:44:31 -0700
commit0e79d96c36aef5889ae2e2a3fc2e96e93f30dc21 (patch)
treebc0a5a7d81ae6b7c82651e5d3046164ba6a0d457
parent1c7ad6773ce6be00dcd6e51e9be08f203abe5071 (diff)
integer overflow in XRRQueryOutputProperty() [CVE-2013-1986 1/4]
rep.length is a CARD32, while rbytes was a signed int, so rbytes = sizeof (XRRPropertyInfo) + rep.length * sizeof (long); could result in integer overflow, leading to an undersized malloc and reading data off the connection and writing it past the end of the allocated buffer. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
-rw-r--r--src/XrrProperty.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/src/XrrProperty.c b/src/XrrProperty.c
index 2b065b2..50382bf 100644
--- a/src/XrrProperty.c
+++ b/src/XrrProperty.c
@@ -31,6 +31,7 @@
#include <X11/extensions/render.h>
#include <X11/extensions/Xrender.h>
#include "Xrandrint.h"
+#include <limits.h>
Atom *
XRRListOutputProperties (Display *dpy, RROutput output, int *nprop)
@@ -84,7 +85,7 @@ XRRQueryOutputProperty (Display *dpy, RROutput output, Atom property)
XExtDisplayInfo *info = XRRFindDisplay(dpy);
xRRQueryOutputPropertyReply rep;
xRRQueryOutputPropertyReq *req;
- int rbytes, nbytes;
+ unsigned int rbytes, nbytes;
XRRPropertyInfo *prop_info;
RRCheckExtension (dpy, info, NULL);
@@ -102,10 +103,14 @@ XRRQueryOutputProperty (Display *dpy, RROutput output, Atom property)
return NULL;
}
- rbytes = sizeof (XRRPropertyInfo) + rep.length * sizeof (long);
- nbytes = rep.length << 2;
+ if (rep.length < ((INT_MAX / sizeof(long)) - sizeof (XRRPropertyInfo))) {
+ rbytes = sizeof (XRRPropertyInfo) + (rep.length * sizeof (long));
+ nbytes = rep.length << 2;
+
+ prop_info = Xmalloc (rbytes);
+ } else
+ prop_info = NULL;
- prop_info = (XRRPropertyInfo *) Xmalloc (rbytes);
if (prop_info == NULL) {
_XEatDataWords(dpy, rep.length);
UnlockDisplay (dpy);