[xorg-x11-server] CVE-2015-0255: unchecked XKB string lengths
Peter Hutterer
whot at fedoraproject.org
Tue Feb 10 22:53:34 UTC 2015
commit 554d394d92c246daaf65100b5af72c628c3502b9
Author: Peter Hutterer <peter.hutterer at who-t.net>
Date: Fri Feb 6 13:38:24 2015 +1000
CVE-2015-0255: unchecked XKB string lengths
...wap-XkbSetGeometry-data-in-the-input-buff.patch | 104 +++++++++++++++
...Check-strings-length-against-request-size.patch | 140 ++++++++++++++++++++
xorg-x11-server.spec | 10 ++-
3 files changed, 253 insertions(+), 1 deletions(-)
---
diff --git a/0001-xkb-Don-t-swap-XkbSetGeometry-data-in-the-input-buff.patch b/0001-xkb-Don-t-swap-XkbSetGeometry-data-in-the-input-buff.patch
new file mode 100644
index 0000000..5edc9c1
--- /dev/null
+++ b/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 at 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 at redhat.com>
+Signed-off-by: Peter Hutterer <peter.hutterer at 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
diff --git a/0002-xkb-Check-strings-length-against-request-size.patch b/0002-xkb-Check-strings-length-against-request-size.patch
new file mode 100644
index 0000000..9c962bc
--- /dev/null
+++ b/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 at 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 at redhat.com>
+Reviewed-by: Peter Hutterer <peter.hutterer at who-t.net>
+Signed-off-by: Peter Hutterer <peter.hutterer at 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
diff --git a/xorg-x11-server.spec b/xorg-x11-server.spec
index ed67c84..1ba80da 100644
--- a/xorg-x11-server.spec
+++ b/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 at redhat.com> 1.16.2.901-3
+- CVE-2015-0255: unchecked XKB string lengths
+
* Thu Feb 05 2015 Ray Strode <rstrode at 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
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