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From 8b14f7b74284900b95a319ec80c4333e63af2296 Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu@bluenote.herrb.com>
Date: Thu, 17 Jan 2008 15:28:42 +0100
Subject: [PATCH] Fix for CVE-2007-6429 - MIT-SHM and EVI extensions integer overflows.
---
Xext/EVI.c | 15 ++++++++++++++-
Xext/sampleEVI.c | 29 ++++++++++++++++++++++++-----
Xext/shm.c | 46 ++++++++++++++++++++++++++++++++++++++--------
3 files changed, 76 insertions(+), 14 deletions(-)
diff --git a/Xext/EVI.c b/Xext/EVI.c
index 8fe3481..13bd32a 100644
--- a/Xext/EVI.c
+++ b/Xext/EVI.c
@@ -34,6 +34,7 @@ THE USE OR PERFORMANCE OF THIS SOFTWARE.
#include <X11/extensions/XEVIstr.h>
#include "EVIstruct.h"
#include "modinit.h"
+#include "scrnintstr.h"
#if 0
static unsigned char XEVIReqCode = 0;
@@ -87,10 +88,22 @@ ProcEVIGetVisualInfo(ClientPtr client)
{
REQUEST(xEVIGetVisualInfoReq);
xEVIGetVisualInfoReply rep;
- int n, n_conflict, n_info, sz_info, sz_conflict;
+ int i, n, n_conflict, n_info, sz_info, sz_conflict;
VisualID32 *conflict;
+ unsigned int total_visuals = 0;
xExtendedVisualInfo *eviInfo;
int status;
+
+ /*
+ * do this first, otherwise REQUEST_FIXED_SIZE can overflow. we assume
+ * here that you don't have more than 2^32 visuals over all your screens;
+ * this seems like a safe assumption.
+ */
+ for (i = 0; i < screenInfo.numScreens; i++)
+ total_visuals += screenInfo.screens[i]->numVisuals;
+ if (stuff->n_visual > total_visuals)
+ return BadValue;
+
REQUEST_FIXED_SIZE(xEVIGetVisualInfoReq, stuff->n_visual * sz_VisualID32);
status = eviPriv->getVisualInfo((VisualID32 *)&stuff[1], (int)stuff->n_visual,
&eviInfo, &n_info, &conflict, &n_conflict);
diff --git a/Xext/sampleEVI.c b/Xext/sampleEVI.c
index 7508aa7..b871bfd 100644
--- a/Xext/sampleEVI.c
+++ b/Xext/sampleEVI.c
@@ -34,6 +34,13 @@ THE USE OR PERFORMANCE OF THIS SOFTWARE.
#include <X11/extensions/XEVIstr.h>
#include "EVIstruct.h"
#include "scrnintstr.h"
+
+#if HAVE_STDINT_H
+#include <stdint.h>
+#elif !defined(UINT32_MAX)
+#define UINT32_MAX 0xffffffffU
+#endif
+
static int sampleGetVisualInfo(
VisualID32 *visual,
int n_visual,
@@ -42,24 +49,36 @@ static int sampleGetVisualInfo(
VisualID32 **conflict_rn,
int *n_conflict_rn)
{
- int max_sz_evi = n_visual * sz_xExtendedVisualInfo * screenInfo.numScreens;
+ unsigned int max_sz_evi;
VisualID32 *temp_conflict;
xExtendedVisualInfo *evi;
- int max_visuals = 0, max_sz_conflict, sz_conflict = 0;
+ unsigned int max_visuals = 0, max_sz_conflict, sz_conflict = 0;
register int visualI, scrI, sz_evi = 0, conflictI, n_conflict;
- *evi_rn = evi = (xExtendedVisualInfo *)xalloc(max_sz_evi);
- if (!*evi_rn)
- return BadAlloc;
+
+ if (n_visual > UINT32_MAX/(sz_xExtendedVisualInfo * screenInfo.numScreens))
+ return BadAlloc;
+ max_sz_evi = n_visual * sz_xExtendedVisualInfo * screenInfo.numScreens;
+
for (scrI = 0; scrI < screenInfo.numScreens; scrI++) {
if (screenInfo.screens[scrI]->numVisuals > max_visuals)
max_visuals = screenInfo.screens[scrI]->numVisuals;
}
+
+ if (n_visual > UINT32_MAX/(sz_VisualID32 * screenInfo.numScreens
+ * max_visuals))
+ return BadAlloc;
max_sz_conflict = n_visual * sz_VisualID32 * screenInfo.numScreens * max_visuals;
+
+ *evi_rn = evi = (xExtendedVisualInfo *)xalloc(max_sz_evi);
+ if (!*evi_rn)
+ return BadAlloc;
+
temp_conflict = (VisualID32 *)xalloc(max_sz_conflict);
if (!temp_conflict) {
xfree(*evi_rn);
return BadAlloc;
}
+
for (scrI = 0; scrI < screenInfo.numScreens; scrI++) {
for (visualI = 0; visualI < n_visual; visualI++) {
evi[sz_evi].core_visual_id = visual[visualI];
diff --git a/Xext/shm.c b/Xext/shm.c
index ac587be..5633be9 100644
--- a/Xext/shm.c
+++ b/Xext/shm.c
@@ -711,6 +711,8 @@ ProcPanoramiXShmCreatePixmap(
int i, j, result, rc;
ShmDescPtr shmdesc;
REQUEST(xShmCreatePixmapReq);
+ unsigned int width, height, depth;
+ unsigned long size;
PanoramiXRes *newPix;
REQUEST_SIZE_MATCH(xShmCreatePixmapReq);
@@ -724,11 +726,26 @@ ProcPanoramiXShmCreatePixmap(
return rc;
VERIFY_SHMPTR(stuff->shmseg, stuff->offset, TRUE, shmdesc, client);
- if (!stuff->width || !stuff->height)
+
+ width = stuff->width;
+ height = stuff->height;
+ depth = stuff->depth;
+ if (!width || !height || !depth)
{
client->errorValue = 0;
return BadValue;
}
+ if (width > 32767 || height > 32767)
+ return BadAlloc;
+ size = PixmapBytePad(width, depth) * height;
+ if (sizeof(size) == 4) {
+ if (size < width * height)
+ return BadAlloc;
+ /* thankfully, offset is unsigned */
+ if (stuff->offset + size < size)
+ return BadAlloc;
+ }
+
if (stuff->depth != 1)
{
pDepth = pDraw->pScreen->allowedDepths;
@@ -739,9 +756,7 @@ ProcPanoramiXShmCreatePixmap(
return BadValue;
}
CreatePmap:
- VERIFY_SHMSIZE(shmdesc, stuff->offset,
- PixmapBytePad(stuff->width, stuff->depth) * stuff->height,
- client);
+ VERIFY_SHMSIZE(shmdesc, stuff->offset, size, client);
if(!(newPix = (PanoramiXRes *) xalloc(sizeof(PanoramiXRes))))
return BadAlloc;
@@ -1040,6 +1055,8 @@ ProcShmCreatePixmap(client)
register int i, rc;
ShmDescPtr shmdesc;
REQUEST(xShmCreatePixmapReq);
+ unsigned int width, height, depth;
+ unsigned long size;
REQUEST_SIZE_MATCH(xShmCreatePixmapReq);
client->errorValue = stuff->pid;
@@ -1052,11 +1069,26 @@ ProcShmCreatePixmap(client)
return rc;
VERIFY_SHMPTR(stuff->shmseg, stuff->offset, TRUE, shmdesc, client);
- if (!stuff->width || !stuff->height)
+
+ width = stuff->width;
+ height = stuff->height;
+ depth = stuff->depth;
+ if (!width || !height || !depth)
{
client->errorValue = 0;
return BadValue;
}
+ if (width > 32767 || height > 32767)
+ return BadAlloc;
+ size = PixmapBytePad(width, depth) * height;
+ if (sizeof(size) == 4) {
+ if (size < width * height)
+ return BadAlloc;
+ /* thankfully, offset is unsigned */
+ if (stuff->offset + size < size)
+ return BadAlloc;
+ }
+
if (stuff->depth != 1)
{
pDepth = pDraw->pScreen->allowedDepths;
@@ -1067,9 +1099,7 @@ ProcShmCreatePixmap(client)
return BadValue;
}
CreatePmap:
- VERIFY_SHMSIZE(shmdesc, stuff->offset,
- PixmapBytePad(stuff->width, stuff->depth) * stuff->height,
- client);
+ VERIFY_SHMSIZE(shmdesc, stuff->offset, size, client);
pMap = (*shmFuncs[pDraw->pScreen->myNum]->CreatePixmap)(
pDraw->pScreen, stuff->width,
stuff->height, stuff->depth,
--
1.5.3.5
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