From 5c539ee6aba5872fcc73aa3d46a4e9a33dc030db Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu@herrb.eu>
Date: Fri, 19 Feb 2021 15:30:39 +0100
Subject: [PATCH] Reject string longer than USHRT_MAX before sending them on
the wire
The X protocol uses CARD16 values to represent the length so
this would overflow.
CVE-2021-31535
Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
https://lists.x.org/archives/xorg-announce/2021-May/003088.html
XLookupColor() and other X libraries function lack proper validation
of the length of their string parameters. If those parameters can be
controlled by an external application (for instance a color name that
can be emitted via a terminal control sequence) it can lead to the
emission of extra X protocol requests to the X server.
Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/lib/libx11/-/commit/8d2e02ae650f00c4a53deb625211a0527126c605]
CVE: CVE-2021-31535
Signed-off-by: Jasper Orschulko <Jasper.Orschulko@iris-sensing.com>
---
src/Font.c | 6 ++++--
src/FontInfo.c | 3 +++
src/FontNames.c | 3 +++
src/GetColor.c | 4 ++++
src/LoadFont.c | 4 ++++
src/LookupCol.c | 6 ++++--
src/ParseCol.c | 5 ++++-
src/QuExt.c | 5 +++++
src/SetFPath.c | 8 +++++++-
src/SetHints.c | 7 +++++++
src/StNColor.c | 3 +++
src/StName.c | 7 ++++++-
12 files changed, 54 insertions(+), 7 deletions(-)
diff --git a/src/Font.c b/src/Font.c
index 09d2ae91..3f468e4b 100644
--- a/src/Font.c
+++ b/src/Font.c
@@ -102,6 +102,8 @@ XFontStruct *XLoadQueryFont(
XF86BigfontCodes *extcodes = _XF86BigfontCodes(dpy);
#endif
+ if (strlen(name) >= USHRT_MAX)
+ return NULL;
if (_XF86LoadQueryLocaleFont(dpy, name, &font_result, (Font *)0))
return font_result;
LockDisplay(dpy);
@@ -662,8 +664,8 @@ int _XF86LoadQueryLocaleFont(
if (!name)
return 0;
- l = strlen(name);
- if (l < 2 || name[l - 1] != '*' || name[l - 2] != '-')
+ l = (int) strlen(name);
+ if (l < 2 || name[l - 1] != '*' || name[l - 2] != '-' || l >= USHRT_MAX)
return 0;
charset = NULL;
/* next three lines stolen from _XkbGetCharset() */
diff --git a/src/FontInfo.c b/src/FontInfo.c
index f870e431..51b48e29 100644
--- a/src/FontInfo.c
+++ b/src/FontInfo.c
@@ -58,6 +58,9 @@ XFontStruct **info) /* RETURN */
register xListFontsReq *req;
int j;
+ if (strlen(pattern) >= USHRT_MAX)
+ return NULL;
+
LockDisplay(dpy);
GetReq(ListFontsWithInfo, req);
req->maxNames = maxNames;
diff --git a/src/FontNames.c b/src/FontNames.c
index b78792d6..4dac4916 100644
--- a/src/FontNames.c
+++ b/src/FontNames.c
@@ -51,6 +51,9 @@ int *actualCount) /* RETURN */
register xListFontsReq *req;
unsigned long rlen = 0;
+ if (strlen(pattern) >= USHRT_MAX)
+ return NULL;
+
LockDisplay(dpy);
GetReq(ListFonts, req);
req->maxNames = maxNames;
diff --git a/src/GetColor.c b/src/GetColor.c
index cd0eb9f6..512ac308 100644
--- a/src/GetColor.c
+++ b/src/GetColor.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include "Xlibint.h"
#include "Xcmsint.h"
@@ -48,6 +49,9 @@ XColor *exact_def) /* RETURN */
XcmsColor cmsColor_exact;
Status ret;
+ if (strlen(colorname) >= USHRT_MAX)
+ return (0);
+
#ifdef XCMS
/*
* Let's Attempt to use Xcms and i18n approach to Parse Color
diff --git a/src/LoadFont.c b/src/LoadFont.c
index f547976b..85735249 100644
--- a/src/LoadFont.c
+++ b/src/LoadFont.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include "Xlibint.h"
Font
@@ -38,6 +39,9 @@ XLoadFont (
Font fid;
register xOpenFontReq *req;
+ if (strlen(name) >= USHRT_MAX)
+ return (0);
+
if (_XF86LoadQueryLocaleFont(dpy, name, (XFontStruct **)0, &fid))
return fid;
diff --git a/src/LookupCol.c b/src/LookupCol.c
index f7f969f5..cd9b1368 100644
--- a/src/LookupCol.c
+++ b/src/LookupCol.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include "Xlibint.h"
#include "Xcmsint.h"
@@ -46,6 +47,9 @@ XLookupColor (
XcmsCCC ccc;
XcmsColor cmsColor_exact;
+ n = (int) strlen (spec);
+ if (n >= USHRT_MAX)
+ return 0;
#ifdef XCMS
/*
* Let's Attempt to use Xcms and i18n approach to Parse Color
@@ -77,8 +81,6 @@ XLookupColor (
* Xcms and i18n methods failed, so lets pass it to the server
* for parsing.
*/
-
- n = strlen (spec);
LockDisplay(dpy);
GetReq (LookupColor, req);
req->cmap = cmap;
diff --git a/src/ParseCol.c b/src/ParseCol.c
index e997b1b8..180132dd 100644
--- a/src/ParseCol.c
+++ b/src/ParseCol.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include "Xlibint.h"
#include "Xcmsint.h"
@@ -46,7 +47,9 @@ XParseColor (
XcmsColor cmsColor;
if (!spec) return(0);
- n = strlen (spec);
+ n = (int) strlen (spec);
+ if (n >= USHRT_MAX)
+ return(0);
if (*spec == '#') {
/*
* RGB
diff --git a/src/QuExt.c b/src/QuExt.c
index 4e230e77..d38a1572 100644
--- a/src/QuExt.c
+++ b/src/QuExt.c
@@ -27,6 +27,8 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
+#include <stdbool.h>
#include "Xlibint.h"
Bool
@@ -40,6 +42,9 @@ XQueryExtension(
xQueryExtensionReply rep;
register xQueryExtensionReq *req;
+ if (strlen(name) >= USHRT_MAX)
+ return false;
+
LockDisplay(dpy);
GetReq(QueryExtension, req);
req->nbytes = name ? strlen(name) : 0;
diff --git a/src/SetFPath.c b/src/SetFPath.c
index 60aaef01..3d8c50cb 100644
--- a/src/SetFPath.c
+++ b/src/SetFPath.c
@@ -26,6 +26,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
+#include <limits.h>
#endif
#include "Xlibint.h"
@@ -48,7 +49,12 @@ XSetFontPath (
GetReq (SetFontPath, req);
req->nFonts = ndirs;
for (i = 0; i < ndirs; i++) {
- n += safestrlen (directories[i]) + 1;
+ n = (int) ((size_t) n + (safestrlen (directories[i]) + 1));
+ if (n >= USHRT_MAX) {
+ UnlockDisplay(dpy);
+ SyncHandle();
+ return 0;
+ }
}
nbytes = (n + 3) & ~3;
req->length += nbytes >> 2;
diff --git a/src/SetHints.c b/src/SetHints.c
index bc46498a..f3d727ec 100644
--- a/src/SetHints.c
+++ b/src/SetHints.c
@@ -49,6 +49,7 @@ SOFTWARE.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <X11/Xlibint.h>
#include <X11/Xutil.h>
#include "Xatomtype.h"
@@ -214,6 +215,8 @@ XSetCommand (
register char *buf, *bp;
for (i = 0, nbytes = 0; i < argc; i++) {
nbytes += safestrlen(argv[i]) + 1;
+ if (nbytes >= USHRT_MAX)
+ return 1;
}
if ((bp = buf = Xmalloc(nbytes))) {
/* copy arguments into single buffer */
@@ -256,6 +259,8 @@ XSetStandardProperties (
if (name != NULL) XStoreName (dpy, w, name);
+ if (safestrlen(icon_string) >= USHRT_MAX)
+ return 1;
if (icon_string != NULL) {
XChangeProperty (dpy, w, XA_WM_ICON_NAME, XA_STRING, 8,
PropModeReplace,
@@ -298,6 +303,8 @@ XSetClassHint(
len_nm = safestrlen(classhint->res_name);
len_cl = safestrlen(classhint->res_class);
+ if (len_nm + len_cl >= USHRT_MAX)
+ return 1;
if ((class_string = s = Xmalloc(len_nm + len_cl + 2))) {
if (len_nm) {
strcpy(s, classhint->res_name);
diff --git a/src/StNColor.c b/src/StNColor.c
index 8b821c3e..ba021958 100644
--- a/src/StNColor.c
+++ b/src/StNColor.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include "Xlibint.h"
#include "Xcmsint.h"
@@ -46,6 +47,8 @@ int flags) /* DoRed, DoGreen, DoBlue */
XcmsColor cmsColor_exact;
XColor scr_def;
+ if (strlen(name) >= USHRT_MAX)
+ return 0;
#ifdef XCMS
/*
* Let's Attempt to use Xcms approach to Parse Color
diff --git a/src/StName.c b/src/StName.c
index b4048bff..5a632d0c 100644
--- a/src/StName.c
+++ b/src/StName.c
@@ -27,6 +27,7 @@ in this Software without prior written authorization from The Open Group.
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
+#include <limits.h>
#include <X11/Xlibint.h>
#include <X11/Xatom.h>
@@ -36,7 +37,9 @@ XStoreName (
Window w,
_Xconst char *name)
{
- return XChangeProperty(dpy, w, XA_WM_NAME, XA_STRING,
+ if (strlen(name) >= USHRT_MAX)
+ return 0;
+ return XChangeProperty(dpy, w, XA_WM_NAME, XA_STRING, /* */
8, PropModeReplace, (_Xconst unsigned char *)name,
name ? strlen(name) : 0);
}
@@ -47,6 +50,8 @@ XSetIconName (
Window w,
_Xconst char *icon_name)
{
+ if (strlen(icon_name) >= USHRT_MAX)
+ return 0;
return XChangeProperty(dpy, w, XA_WM_ICON_NAME, XA_STRING, 8,
PropModeReplace, (_Xconst unsigned char *)icon_name,
icon_name ? strlen(icon_name) : 0);
--
2.32.0