diff options
| author | Alan Coopersmith <alan.coopersmith@oracle.com> | 2013-03-02 15:08:21 -0800 |
|---|---|---|
| committer | Alan Coopersmith <alan.coopersmith@oracle.com> | 2013-05-09 18:59:53 -0700 |
| commit | 833f6b70bc789d33607f6dbfee9e0a4178ec4b59 (patch) | |
| tree | c2e4d0c2461d78f95cd82ac980d44f03fb5e2d98 | |
| parent | 79d8dc08eb98842173ce239b9dd60df0e9e9ae72 (diff) | |
integer overflow in XGetImage() [CVE-2013-1981 11/13]
Ensure that we don't underallocate when the server claims to have sent a
very large reply.
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Matthieu Herrb <matthieu.herrb@laas.fr>
| -rw-r--r-- | src/GetImage.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/src/GetImage.c b/src/GetImage.c index e8f1b030..c461abc0 100644 --- a/src/GetImage.c +++ b/src/GetImage.c @@ -30,6 +30,7 @@ in this Software without prior written authorization from The Open Group. #include "Xlibint.h" #include <X11/Xutil.h> /* for XDestroyImage */ #include "ImUtil.h" +#include <limits.h> #define ROUNDUP(nbytes, pad) (((((nbytes) - 1) + (pad)) / (pad)) * (pad)) @@ -56,7 +57,7 @@ XImage *XGetImage ( xGetImageReply rep; register xGetImageReq *req; char *data; - long nbytes; + unsigned long nbytes; XImage *image; LockDisplay(dpy); GetReq (GetImage, req); @@ -78,10 +79,13 @@ XImage *XGetImage ( return (XImage *)NULL; } - nbytes = (long)rep.length << 2; - data = (char *) Xmalloc((unsigned) nbytes); + if (rep.length < (INT_MAX >> 2)) { + nbytes = (unsigned long)rep.length << 2; + data = Xmalloc(nbytes); + } else + data = NULL; if (! data) { - _XEatData(dpy, (unsigned long) nbytes); + _XEatDataWords(dpy, rep.length); UnlockDisplay(dpy); SyncHandle(); return (XImage *) NULL; |