From 81c90dc8f0aae3b65730409b1b615b5fa7280ebd Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 16 Jan 2015 20:08:59 +0100
Subject: 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>

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);
-- 
cgit v0.10.2

From 20079c36cf7d377938ca5478447d8b9045cb7d43 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 16 Jan 2015 08:44:45 +0100
Subject: 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>

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;
-- 
cgit v0.10.2

