Module Name: xsrc
Committed By: mrg
Date: Sat Apr 18 03:35:40 UTC 2015
Modified Files:
xsrc/xfree/xc/lib/X11: Xlibint.h
Log Message:
fix CVE-2013-7439: Buffer overflow in MakeBigReq macro in libX11 prior to 1.6
port the fixes in libX11 1.6 back to xfree tree from:
http://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=39547d600a13713e15429f49768e54c3173c828d
To generate a diff of this commit:
cvs rdiff -u -r1.1.1.7 -r1.2 xsrc/xfree/xc/lib/X11/Xlibint.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: xsrc/xfree/xc/lib/X11/Xlibint.h
diff -u xsrc/xfree/xc/lib/X11/Xlibint.h:1.1.1.7 xsrc/xfree/xc/lib/X11/Xlibint.h:1.2
--- xsrc/xfree/xc/lib/X11/Xlibint.h:1.1.1.7 Fri Mar 18 13:04:29 2005
+++ xsrc/xfree/xc/lib/X11/Xlibint.h Sat Apr 18 03:35:40 2015
@@ -528,6 +528,14 @@ extern LockInfoPtr _Xglobal_lock;
#endif
#ifdef WORD64
+/*
+ * MakeBigReq sets the CARD16 "req->length" to 0 and inserts a new CARD32
+ * length, after req->length, before the data in the request. The new length
+ * includes the "n" extra 32-bit words.
+ *
+ * Do not use MakeBigReq if there is no data already in the request.
+ * req->length must already be >= 2.
+ */
#define MakeBigReq(req,n) \
{ \
char _BRdat[4]; \
@@ -546,7 +554,7 @@ extern LockInfoPtr _Xglobal_lock;
CARD32 _BRlen = req->length - 1; \
req->length = 0; \
_BRdat = ((CARD32 *)req)[_BRlen]; \
- memmove(((char *)req) + 8, ((char *)req) + 4, _BRlen << 2); \
+ memmove(((char *)req) + 8, ((char *)req) + 4, (_BRlen - 1) << 2); \
((CARD32 *)req)[1] = _BRlen + n + 2; \
Data32(dpy, &_BRdat, 4); \
}
@@ -557,13 +565,20 @@ extern LockInfoPtr _Xglobal_lock;
CARD32 _BRlen = req->length - 1; \
req->length = 0; \
_BRdat = ((CARD32 *)req)[_BRlen]; \
- memmove(((char *)req) + 8, ((char *)req) + 4, _BRlen << 2); \
+ memmove(((char *)req) + 8, ((char *)req) + 4, (_BRlen - 1) << 2); \
((CARD32 *)req)[1] = _BRlen + n + 2; \
Data32(dpy, &_BRdat, 4); \
}
#endif
#endif
+/*
+ * SetReqLen increases the count of 32-bit words in the request by "n",
+ * or by "badlen" if "n" is too large.
+ *
+ * Do not use SetReqLen if "req" does not already have data after the
+ * xReq header. req->length must already be >= 2.
+ */
#define SetReqLen(req,n,badlen) \
if ((req->length + n) > (unsigned)65535) { \
if (dpy->bigreq_size) { \
