File U_Avoid-out-of-boundary-accesses-on-illegal-responses.patch of Package libXrandr
From a0df3e1c7728205e5c7650b2e6dce684139254a6 Mon Sep 17 00:00:00 2001
From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Sun, 25 Sep 2016 22:21:40 +0200
Subject: [PATCH] Avoid out of boundary accesses on illegal responses
The responses of the connected X server have to be properly checked
to avoid out of boundary accesses that could otherwise be triggered
by a malicious server.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Reviewed-by: Matthieu Herrb <matthieu@herrb.eu>
---
src/XrrConfig.c | 32 +++++++++++++--------
src/XrrCrtc.c | 83 ++++++++++++++++++++++++++++++++++++++++++-------------
src/XrrMonitor.c | 18 ++++++++++++
src/XrrOutput.c | 11 ++++++++
src/XrrProvider.c | 28 ++++++++++++++++---
src/XrrScreen.c | 52 ++++++++++++++++++++++------------
6 files changed, 172 insertions(+), 52 deletions(-)
Index: libXrandr-1.5.0/src/XrrConfig.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrConfig.c
+++ libXrandr-1.5.0/src/XrrConfig.c
@@ -29,6 +29,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -272,23 +273,30 @@ static XRRScreenConfiguration *_XRRGetSc
rep.rate = 0;
rep.nrateEnts = 0;
}
+ if (rep.length < INT_MAX >> 2) {
+ nbytes = (long) rep.length << 2;
- nbytes = (long) rep.length << 2;
+ nbytesRead = (long) (rep.nSizes * SIZEOF (xScreenSizes) +
+ ((rep.nrateEnts + 1)& ~1) * 2 /* SIZEOF(CARD16) */);
- nbytesRead = (long) (rep.nSizes * SIZEOF (xScreenSizes) +
- ((rep.nrateEnts + 1)& ~1) * 2 /* SIZEOF (CARD16) */);
+ /*
+ * first we must compute how much space to allocate for
+ * randr library's use; we'll allocate the structures in a single
+ * allocation, on cleanlyness grounds.
+ */
+
+ rbytes = sizeof (XRRScreenConfiguration) +
+ (rep.nSizes * sizeof (XRRScreenSize) +
+ rep.nrateEnts * sizeof (int));
- /*
- * first we must compute how much space to allocate for
- * randr library's use; we'll allocate the structures in a single
- * allocation, on cleanlyness grounds.
- */
-
- rbytes = sizeof (XRRScreenConfiguration) +
- (rep.nSizes * sizeof (XRRScreenSize) +
- rep.nrateEnts * sizeof (int));
+ scp = (struct _XRRScreenConfiguration *) Xmalloc(rbytes);
+ } else {
+ nbytes = 0;
+ nbytesRead = 0;
+ rbytes = 0;
+ scp = NULL;
+ }
- scp = (struct _XRRScreenConfiguration *) Xmalloc(rbytes);
if (scp == NULL) {
_XEatData (dpy, (unsigned long) nbytes);
return NULL;
Index: libXrandr-1.5.0/src/XrrCrtc.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrCrtc.c
+++ libXrandr-1.5.0/src/XrrCrtc.c
@@ -24,6 +24,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -57,22 +58,33 @@ XRRGetCrtcInfo (Display *dpy, XRRScreenR
return NULL;
}
- nbytes = (long) rep.length << 2;
+ if (rep.length < INT_MAX >> 2)
+ {
+ nbytes = (long) rep.length << 2;
- nbytesRead = (long) (rep.nOutput * 4 +
- rep.nPossibleOutput * 4);
+ nbytesRead = (long) (rep.nOutput * 4 +
+ rep.nPossibleOutput * 4);
- /*
- * first we must compute how much space to allocate for
- * randr library's use; we'll allocate the structures in a single
- * allocation, on cleanlyness grounds.
- */
+ /*
+ * first we must compute how much space to allocate for
+ * randr library's use; we'll allocate the structures in a single
+ * allocation, on cleanlyness grounds.
+ */
+
+ rbytes = (sizeof (XRRCrtcInfo) +
+ rep.nOutput * sizeof (RROutput) +
+ rep.nPossibleOutput * sizeof (RROutput));
- rbytes = (sizeof (XRRCrtcInfo) +
- rep.nOutput * sizeof (RROutput) +
- rep.nPossibleOutput * sizeof (RROutput));
+ xci = (XRRCrtcInfo *) Xmalloc(rbytes);
+ }
+ else
+ {
+ nbytes = 0;
+ nbytesRead = 0;
+ rbytes = 0;
+ xci = NULL;
+ }
- xci = (XRRCrtcInfo *) Xmalloc(rbytes);
if (xci == NULL) {
_XEatDataWords (dpy, rep.length);
UnlockDisplay (dpy);
@@ -194,12 +206,21 @@ XRRGetCrtcGamma (Display *dpy, RRCrtc cr
if (!_XReply (dpy, (xReply *) &rep, 0, xFalse))
goto out;
- nbytes = (long) rep.length << 2;
+ if (rep.length < INT_MAX >> 2)
+ {
+ nbytes = (long) rep.length << 2;
- /* three channels of CARD16 data */
- nbytesRead = (rep.size * 2 * 3);
+ /* three channels of CARD16 data */
+ nbytesRead = (rep.size * 2 * 3);
- crtc_gamma = XRRAllocGamma (rep.size);
+ crtc_gamma = XRRAllocGamma (rep.size);
+ }
+ else
+ {
+ nbytes = 0;
+ nbytesRead = 0;
+ crtc_gamma = NULL;
+ }
if (!crtc_gamma)
{
@@ -357,7 +378,7 @@ XRRGetCrtcTransform (Display *dpy,
xRRGetCrtcTransformReq *req;
int major_version, minor_version;
XRRCrtcTransformAttributes *attr;
- char *extra = NULL, *e;
+ char *extra = NULL, *end = NULL, *e;
int p;
*attributes = NULL;
@@ -395,9 +416,17 @@ XRRGetCrtcTransform (Display *dpy,
else
{
int extraBytes = rep.length * 4 - CrtcTransformExtra;
- extra = Xmalloc (extraBytes);
+ if (rep.length < INT_MAX / 4 &&
+ rep.length * 4 >= CrtcTransformExtra) {
+ extra = Xmalloc (extraBytes);
+ end = extra + extraBytes;
+ } else
+ extra = NULL;
if (!extra) {
- _XEatDataWords (dpy, rep.length - (CrtcTransformExtra >> 2));
+ if (rep.length > (CrtcTransformExtra >> 2))
+ _XEatDataWords (dpy, rep.length - (CrtcTransformExtra >> 2));
+ else
+ _XEatDataWords (dpy, rep.length);
UnlockDisplay (dpy);
SyncHandle ();
return False;
@@ -429,22 +458,38 @@ XRRGetCrtcTransform (Display *dpy,
e = extra;
+ if (e + rep.pendingNbytesFilter > end) {
+ XFree (extra);
+ return False;
+ }
memcpy (attr->pendingFilter, e, rep.pendingNbytesFilter);
attr->pendingFilter[rep.pendingNbytesFilter] = '\0';
e += (rep.pendingNbytesFilter + 3) & ~3;
for (p = 0; p < rep.pendingNparamsFilter; p++) {
INT32 f;
+ if (e + 4 > end) {
+ XFree (extra);
+ return False;
+ }
memcpy (&f, e, 4);
e += 4;
attr->pendingParams[p] = (XFixed) f;
}
attr->pendingNparams = rep.pendingNparamsFilter;
+ if (e + rep.currentNbytesFilter > end) {
+ XFree (extra);
+ return False;
+ }
memcpy (attr->currentFilter, e, rep.currentNbytesFilter);
attr->currentFilter[rep.currentNbytesFilter] = '\0';
e += (rep.currentNbytesFilter + 3) & ~3;
for (p = 0; p < rep.currentNparamsFilter; p++) {
INT32 f;
+ if (e + 4 > end) {
+ XFree (extra);
+ return False;
+ }
memcpy (&f, e, 4);
e += 4;
attr->currentParams[p] = (XFixed) f;
Index: libXrandr-1.5.0/src/XrrMonitor.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrMonitor.c
+++ libXrandr-1.5.0/src/XrrMonitor.c
@@ -24,6 +24,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -65,6 +66,15 @@ XRRGetMonitors(Display *dpy, Window wind
return NULL;
}
+ if (rep.length > INT_MAX >> 2 ||
+ rep.nmonitors > INT_MAX / SIZEOF(xRRMonitorInfo) ||
+ rep.noutputs > INT_MAX / 4 ||
+ rep.nmonitors * SIZEOF(xRRMonitorInfo) > INT_MAX - rep.noutputs * 4) {
+ _XEatData (dpy, rep.length);
+ UnlockDisplay (dpy);
+ SyncHandle ();
+ return NULL;
+ }
nbytes = (long) rep.length << 2;
nmon = rep.nmonitors;
noutput = rep.noutputs;
@@ -111,6 +121,14 @@ XRRGetMonitors(Display *dpy, Window wind
mon[m].outputs = output;
buf += SIZEOF (xRRMonitorInfo);
xoutput = (CARD32 *) buf;
+ if (xmon->noutput > rep.noutputs) {
+ Xfree(buf);
+ Xfree(mon);
+ UnlockDisplay (dpy);
+ SyncHandle ();
+ return NULL;
+ }
+ rep.noutputs -= xmon->noutput;
for (o = 0; o < xmon->noutput; o++)
output[o] = xoutput[o];
output += xmon->noutput;
Index: libXrandr-1.5.0/src/XrrOutput.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrOutput.c
+++ libXrandr-1.5.0/src/XrrOutput.c
@@ -25,6 +25,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -60,6 +61,16 @@ XRRGetOutputInfo (Display *dpy, XRRScree
return NULL;
}
+ if (rep.length > INT_MAX >> 2 || rep.length < (OutputInfoExtra >> 2))
+ {
+ if (rep.length > (OutputInfoExtra >> 2))
+ _XEatDataWords (dpy, rep.length - (OutputInfoExtra >> 2));
+ else
+ _XEatDataWords (dpy, rep.length);
+ UnlockDisplay (dpy);
+ SyncHandle ();
+ return NULL;
+ }
nbytes = ((long) (rep.length) << 2) - OutputInfoExtra;
nbytesRead = (long) (rep.nCrtcs * 4 +
Index: libXrandr-1.5.0/src/XrrProvider.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrProvider.c
+++ libXrandr-1.5.0/src/XrrProvider.c
@@ -25,6 +25,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -59,12 +60,20 @@ XRRGetProviderResources(Display *dpy, Wi
return NULL;
}
- nbytes = (long) rep.length << 2;
+ if (rep.length < INT_MAX >> 2) {
+ nbytes = (long) rep.length << 2;
- nbytesRead = (long) (rep.nProviders * 4);
+ nbytesRead = (long) (rep.nProviders * 4);
- rbytes = (sizeof(XRRProviderResources) + rep.nProviders * sizeof(RRProvider));
- xrpr = (XRRProviderResources *) Xmalloc(rbytes);
+ rbytes = (sizeof(XRRProviderResources) + rep.nProviders *
+ sizeof(RRProvider));
+ xrpr = (XRRProviderResources *) Xmalloc(rbytes);
+ } else {
+ nbytes = 0;
+ nbytesRead = 0;
+ rbytes = 0;
+ xrpr = NULL;
+ }
if (xrpr == NULL) {
_XEatDataWords (dpy, rep.length);
@@ -119,6 +128,17 @@ XRRGetProviderInfo(Display *dpy, XRRScre
UnlockDisplay (dpy);
SyncHandle ();
return NULL;
+ }
+
+ if (rep.length > INT_MAX >> 2 || rep.length < ProviderInfoExtra >> 2)
+ {
+ if (rep.length < ProviderInfoExtra >> 2)
+ _XEatDataWords (dpy, rep.length);
+ else
+ _XEatDataWords (dpy, rep.length - (ProviderInfoExtra >> 2));
+ UnlockDisplay (dpy);
+ SyncHandle ();
+ return NULL;
}
nbytes = ((long) rep.length << 2) - ProviderInfoExtra;
Index: libXrandr-1.5.0/src/XrrScreen.c
===================================================================
--- libXrandr-1.5.0.orig/src/XrrScreen.c
+++ libXrandr-1.5.0/src/XrrScreen.c
@@ -24,6 +24,7 @@
#include <config.h>
#endif
+#include <limits.h>
#include <stdio.h>
#include <X11/Xlib.h>
/* we need to be able to manipulate the Display structure on events */
@@ -105,27 +106,36 @@ doGetScreenResources (Display *dpy, Wind
xrri->has_rates = _XRRHasRates (xrri->minor_version, xrri->major_version);
}
- nbytes = (long) rep.length << 2;
+ if (rep.length < INT_MAX >> 2) {
+ nbytes = (long) rep.length << 2;
- nbytesRead = (long) (rep.nCrtcs * 4 +
- rep.nOutputs * 4 +
- rep.nModes * SIZEOF (xRRModeInfo) +
- ((rep.nbytesNames + 3) & ~3));
-
- /*
- * first we must compute how much space to allocate for
- * randr library's use; we'll allocate the structures in a single
- * allocation, on cleanlyness grounds.
- */
-
- rbytes = (sizeof (XRRScreenResources) +
- rep.nCrtcs * sizeof (RRCrtc) +
- rep.nOutputs * sizeof (RROutput) +
- rep.nModes * sizeof (XRRModeInfo) +
- rep.nbytesNames + rep.nModes); /* '\0' terminate names */
+ nbytesRead = (long) (rep.nCrtcs * 4 +
+ rep.nOutputs * 4 +
+ rep.nModes * SIZEOF (xRRModeInfo) +
+ ((rep.nbytesNames + 3) & ~3));
+
+ /*
+ * first we must compute how much space to allocate for
+ * randr library's use; we'll allocate the structures in a single
+ * allocation, on cleanlyness grounds.
+ */
+
+ rbytes = (sizeof (XRRScreenResources) +
+ rep.nCrtcs * sizeof (RRCrtc) +
+ rep.nOutputs * sizeof (RROutput) +
+ rep.nModes * sizeof (XRRModeInfo) +
+ rep.nbytesNames + rep.nModes); /* '\0' terminate names */
+
+ xrsr = (XRRScreenResources *) Xmalloc(rbytes);
+ wire_names = (char *) Xmalloc (rep.nbytesNames);
+ } else {
+ nbytes = 0;
+ nbytesRead = 0;
+ rbytes = 0;
+ xrsr = NULL;
+ wire_names = NULL;
+ }
- xrsr = (XRRScreenResources *) Xmalloc(rbytes);
- wire_names = (char *) Xmalloc (rep.nbytesNames);
if (xrsr == NULL || wire_names == NULL) {
if (xrsr) Xfree (xrsr);
if (wire_names) Xfree (wire_names);
@@ -174,6 +184,14 @@ doGetScreenResources (Display *dpy, Wind
wire_name = wire_names;
for (i = 0; i < rep.nModes; i++) {
xrsr->modes[i].name = names;
+ if (xrsr->modes[i].nameLength > rep.nbytesNames) {
+ Xfree (xrsr);
+ Xfree (wire_names);
+ UnlockDisplay (dpy);
+ SyncHandle ();
+ return NULL;
+ }
+ rep.nbytesNames -= xrsr->modes[i].nameLength;
memcpy (names, wire_name, xrsr->modes[i].nameLength);
names[xrsr->modes[i].nameLength] = '\0';
names += xrsr->modes[i].nameLength + 1;
