CVE-2015-0255: unchecked XKB string lengths

0001-xkb-Don-t-swap-XkbSetGeometry-data-in-the-input-buff.patch

@@ -0,0 +1,104 @@
+From 56306e378787d1f04e159e2b3f99d2611bf51563 Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Fri, 16 Jan 2015 20:08:59 +0100
+Subject: [PATCH 1/2] xkb: Don't swap XkbSetGeometry data in the input buffer
+
+The XkbSetGeometry request embeds data which needs to be swapped when the
+server and the client have different endianess.
+
+_XkbSetGeometry() invokes functions that swap these data directly in the
+input buffer.
+
+However, ProcXkbSetGeometry() may call _XkbSetGeometry() more than once
+(if there is more than one keyboard), thus causing on swapped clients the
+same data to be swapped twice in memory, further causing a server crash
+because the strings lengths on the second time are way off bounds.
+
+To allow _XkbSetGeometry() to run reliably more than once with swapped
+clients, do not swap the data in the buffer, use variables instead.
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
+---
+ xkb/xkb.c | 35 +++++++++++++++++++----------------
+ 1 file changed, 19 insertions(+), 16 deletions(-)
+
+diff --git a/xkb/xkb.c b/xkb/xkb.c
+index 15c7f34..b9a3ac4 100644
+--- a/xkb/xkb.c
++++ b/xkb/xkb.c
+@@ -4961,14 +4961,13 @@ static char *
+ _GetCountedString(char **wire_inout, Bool swap)
+ {
+     char *wire, *str;
+-    CARD16 len, *plen;
++    CARD16 len;
+
+     wire = *wire_inout;
+-    plen = (CARD16 *) wire;
++    len = *(CARD16 *) wire;
+     if (swap) {
+-        swaps(plen);
++        swaps(&len);
+     }
+-    len = *plen;
+     str = malloc(len + 1);
+     if (str) {
+         memcpy(str, &wire[2], len);
+@@ -4985,25 +4984,28 @@ _CheckSetDoodad(char **wire_inout,
+ {
+     char *wire;
+     xkbDoodadWireDesc *dWire;
++    xkbAnyDoodadWireDesc any;
++    xkbTextDoodadWireDesc text;
+     XkbDoodadPtr doodad;
+
+     dWire = (xkbDoodadWireDesc *) (*wire_inout);
++    any = dWire->any;
+     wire = (char *) &dWire[1];
+     if (client->swapped) {
+-        swapl(&dWire->any.name);
+-        swaps(&dWire->any.top);
+-        swaps(&dWire->any.left);
+-        swaps(&dWire->any.angle);
++        swapl(&any.name);
++        swaps(&any.top);
++        swaps(&any.left);
++        swaps(&any.angle);
+     }
+     CHK_ATOM_ONLY(dWire->any.name);
+-    doodad = XkbAddGeomDoodad(geom, section, dWire->any.name);
++    doodad = XkbAddGeomDoodad(geom, section, any.name);
+     if (!doodad)
+         return BadAlloc;
+     doodad->any.type = dWire->any.type;
+     doodad->any.priority = dWire->any.priority;
+-    doodad->any.top = dWire->any.top;
+-    doodad->any.left = dWire->any.left;
+-    doodad->any.angle = dWire->any.angle;
++    doodad->any.top = any.top;
++    doodad->any.left = any.left;
++    doodad->any.angle = any.angle;
+     switch (doodad->any.type) {
+     case XkbOutlineDoodad:
+     case XkbSolidDoodad:
+@@ -5026,12 +5028,13 @@ _CheckSetDoodad(char **wire_inout,
+                                               dWire->text.colorNdx);
+             return BadMatch;
+         }
++        text = dWire->text;
+         if (client->swapped) {
+-            swaps(&dWire->text.width);
+-            swaps(&dWire->text.height);
++            swaps(&text.width);
++            swaps(&text.height);
+         }
+-        doodad->text.width = dWire->text.width;
+-        doodad->text.height = dWire->text.height;
++        doodad->text.width = text.width;
++        doodad->text.height = text.height;
+         doodad->text.color_ndx = dWire->text.colorNdx;
+         doodad->text.text = _GetCountedString(&wire, client->swapped);
+         doodad->text.font = _GetCountedString(&wire, client->swapped);
+--
+2.1.0

0002-xkb-Check-strings-length-against-request-size.patch

@@ -0,0 +1,140 @@
+From ab0fd32fb12b2153177dd101976c9dd23793b947 Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Fri, 16 Jan 2015 08:44:45 +0100
+Subject: [PATCH 2/2] xkb: Check strings length against request size
+
+Ensure that the given strings length in an XkbSetGeometry request remain
+within the limits of the size of the request.
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
+Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
+---
+ xkb/xkb.c | 65 +++++++++++++++++++++++++++++++++++++++------------------------
+ 1 file changed, 40 insertions(+), 25 deletions(-)
+
+diff --git a/xkb/xkb.c b/xkb/xkb.c
+index b9a3ac4..f3988f9 100644
+--- a/xkb/xkb.c
++++ b/xkb/xkb.c
+@@ -4957,25 +4957,29 @@ ProcXkbGetGeometry(ClientPtr client)
+
+ /***====================================================================***/
+
+-static char *
+-_GetCountedString(char **wire_inout, Bool swap)
++static Status
++_GetCountedString(char **wire_inout, ClientPtr client, char **str)
+ {
+-    char *wire, *str;
++    char *wire, *next;
+     CARD16 len;
+
+     wire = *wire_inout;
+     len = *(CARD16 *) wire;
+-    if (swap) {
++    if (client->swapped) {
+         swaps(&len);
+     }
+-    str = malloc(len + 1);
+-    if (str) {
+-        memcpy(str, &wire[2], len);
+-        str[len] = '\0';
+-    }
+-    wire += XkbPaddedSize(len + 2);
+-    *wire_inout = wire;
+-    return str;
++    next = wire + XkbPaddedSize(len + 2);
++    /* Check we're still within the size of the request */
++    if (client->req_len <
++        bytes_to_int32(next - (char *) client->requestBuffer))
++        return BadValue;
++    *str = malloc(len + 1);
++    if (!*str)
++        return BadAlloc;
++    memcpy(*str, &wire[2], len);
++    *(*str + len) = '\0';
++    *wire_inout = next;
++    return Success;
+ }
+
+ static Status
+@@ -4987,6 +4991,7 @@ _CheckSetDoodad(char **wire_inout,
+     xkbAnyDoodadWireDesc any;
+     xkbTextDoodadWireDesc text;
+     XkbDoodadPtr doodad;
++    Status status;
+
+     dWire = (xkbDoodadWireDesc *) (*wire_inout);
+     any = dWire->any;
+@@ -5036,8 +5041,14 @@ _CheckSetDoodad(char **wire_inout,
+         doodad->text.width = text.width;
+         doodad->text.height = text.height;
+         doodad->text.color_ndx = dWire->text.colorNdx;
+-        doodad->text.text = _GetCountedString(&wire, client->swapped);
+-        doodad->text.font = _GetCountedString(&wire, client->swapped);
++        status = _GetCountedString(&wire, client, &doodad->text.text);
++        if (status != Success)
++            return status;
++        status = _GetCountedString(&wire, client, &doodad->text.font);
++        if (status != Success) {
++            free (doodad->text.text);
++            return status;
++        }
+         break;
+     case XkbIndicatorDoodad:
+         if (dWire->indicator.onColorNdx >= geom->num_colors) {
+@@ -5072,7 +5083,9 @@ _CheckSetDoodad(char **wire_inout,
+         }
+         doodad->logo.color_ndx = dWire->logo.colorNdx;
+         doodad->logo.shape_ndx = dWire->logo.shapeNdx;
+-        doodad->logo.logo_name = _GetCountedString(&wire, client->swapped);
++        status = _GetCountedString(&wire, client, &doodad->logo.logo_name);
++        if (status != Success)
++            return status;
+         break;
+     default:
+         client->errorValue = _XkbErrCode2(0x4F, dWire->any.type);
+@@ -5304,18 +5317,20 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
+     char *wire;
+
+     wire = (char *) &req[1];
+-    geom->label_font = _GetCountedString(&wire, client->swapped);
++    status = _GetCountedString(&wire, client, &geom->label_font);
++    if (status != Success)
++        return status;
+
+     for (i = 0; i < req->nProperties; i++) {
+         char *name, *val;
+
+-        name = _GetCountedString(&wire, client->swapped);
+-        if (!name)
+-            return BadAlloc;
+-        val = _GetCountedString(&wire, client->swapped);
+-        if (!val) {
++        status = _GetCountedString(&wire, client, &name);
++        if (status != Success)
++            return status;
++        status = _GetCountedString(&wire, client, &val);
++        if (status != Success) {
+             free(name);
+-            return BadAlloc;
++            return status;
+         }
+         if (XkbAddGeomProperty(geom, name, val) == NULL) {
+             free(name);
+@@ -5349,9 +5364,9 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
+     for (i = 0; i < req->nColors; i++) {
+         char *name;
+
+-        name = _GetCountedString(&wire, client->swapped);
+-        if (!name)
+-            return BadAlloc;
++        status = _GetCountedString(&wire, client, &name);
++        if (status != Success)
++            return status;
+         if (!XkbAddGeomColor(geom, name, geom->num_colors)) {
+             free(name);
+             return BadAlloc;
+--
+2.1.0

xorg-x11-server.spec

@@ -42,7 +42,7 @@
 Summary:   X.Org X11 X server
 Name:      xorg-x11-server
 Version:   1.16.2.901
-Release:   2%{?gitdate:.%{gitdate}}%{dist}
+Release:   3%{?gitdate:.%{gitdate}}%{dist}
 URL:       http://www.x.org
 License:   MIT
 Group:     User Interface/X
@@ -104,6 +104,11 @@ Patch10200: 0001-xwayland-Snap-damage-reports-to-the-bounding-box.patch
 
 # already in master:
 Patch10300: glamor-add-shm-sync-fence-support.patch
+
+# CVE-2015-0255
+Patch10400: 0001-xkb-Don-t-swap-XkbSetGeometry-data-in-the-input-buff.patch
+Patch10401: 0002-xkb-Check-strings-length-against-request-size.patch
+
 %global moduledir	%{_libdir}/xorg/modules
 %global drimoduledir	%{_libdir}/dri
 %global sdkdir		%{_includedir}/xorg
@@ -633,6 +638,9 @@ find %{inst_srcdir}/hw/xfree86 -name \*.c -delete
 
 
 %changelog
+* Fri Feb 06 2015 Peter Hutterer <peter.hutterer@redhat.com> 1.16.2.901-3
+- CVE-2015-0255: unchecked XKB string lengths
+
 * Thu Feb 05 2015 Ray Strode <rstrode@redhat.com> 1.16.2.901-2
 - Add patch from ickle to fix flicker on login / durin vt switch
   see https://bugzilla.gnome.org/show_bug.cgi?id=737226