xserver-xorg: Fix CVE-2026-34000

Pick patch according to [1]

[1] https://lists.x.org/archives/xorg-announce/2026-April/003677.html
[2] https://security-tracker.debian.org/tracker/CVE-2026-34000

(From OE-Core rev: 3611b45c3c0144172c032964bf0d601dba649b49)

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Yoann Congal <yoann.congal@smile.fr>
Signed-off-by: Paul Barker <paul@pbarker.dev>

meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2026-34000.patch

@@ -0,0 +1,72 @@
+From 81b6a34f90b28c32ad499a78a4f391b7c06daea2 Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Wed, 18 Feb 2026 16:03:11 +0100
+Subject: [PATCH] xkb: Fix bounds check in _CheckSetGeom()
+
+As reported by valgrind:
+
+  == Conditional jump or move depends on uninitialised value(s)
+  ==    at 0x5CBE66: SrvXkbAddGeomKeyAlias (XKBGAlloc.c:585)
+  ==    by 0x5AC7D5: _CheckSetGeom (xkb.c:5607)
+  ==    by 0x5AC952: _XkbSetGeometry (xkb.c:5643)
+  ==    by 0x5ACB58: ProcXkbSetGeometry (xkb.c:5684)
+  ==    by 0x5B0DAC: ProcXkbDispatch (xkb.c:7070)
+  ==    by 0x4A28C5: Dispatch (dispatch.c:553)
+  ==    by 0x4B0B24: dix_main (main.c:274)
+  ==    by 0x42915E: main (stubmain.c:34)
+  ==  Uninitialised value was created by a heap allocation
+  ==    at 0x4840B26: malloc (vg_replace_malloc.c:447)
+  ==    by 0x5E13B0: AllocateInputBuffer (io.c:981)
+  ==    by 0x5E05CD: InsertFakeRequest (io.c:516)
+  ==    by 0x4AA860: NextAvailableClient (dispatch.c:3629)
+  ==    by 0x5DE0D7: AllocNewConnection (connection.c:628)
+  ==    by 0x5DE2C6: EstablishNewConnections (connection.c:692)
+  ==    by 0x5DE600: HandleNotifyFd (connection.c:809)
+  ==    by 0x5E2598: ospoll_wait (ospoll.c:660)
+  ==    by 0x5DA00C: WaitForSomething (WaitFor.c:208)
+  ==    by 0x4A26E5: Dispatch (dispatch.c:493)
+  ==    by 0x4B0B24: dix_main (main.c:274)
+  ==    by 0x42915E: main (stubmain.c:34)
+
+Each key alias entry contains two key names (the alias and the real key
+name), each of size XkbKeyNameLength.
+
+The current bounds check only validates the first name, allowing
+XkbAddGeomKeyAlias to potentially read uninitialized memory when
+accessing the second name at &wire[XkbKeyNameLength].
+
+To fix this, change the value to check to use 2 * XkbKeyNameLength to
+validate the bounds.
+
+CVE-2026-34000, ZDI-CAN-28679
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with TrendAI Zero Day Initiative
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
+Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/81b6a34f90b28c32ad499a78a4f391b7c06daea2]
+CVE: CVE-2026-34000
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ xkb/xkb.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/xkb/xkb.c b/xkb/xkb.c
+index 2b9004a..1ba638b 100644
+--- a/xkb/xkb.c
++++ b/xkb/xkb.c
+@@ -5603,7 +5603,7 @@ _CheckSetGeom(XkbGeometryPtr geom, xkbSetGeometryReq * req, ClientPtr client)
+     }
+ 
+     for (i = 0; i < req->nKeyAliases; i++) {
+-        if (!_XkbCheckRequestBounds(client, req, wire, wire + XkbKeyNameLength))
++        if (!_XkbCheckRequestBounds(client, req, wire, wire + 2 * XkbKeyNameLength))
+                 return BadLength;
+ 
+         if (XkbAddGeomKeyAlias(geom, &wire[XkbKeyNameLength], wire) == NULL)
+-- 
+2.43.0
+

meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.18.bb

@@ -6,6 +6,7 @@ SRC_URI += "file://0001-xf86pciBus.c-use-Intel-ddx-only-for-pre-gen4-hardwar.pat
             file://0003-xkb-Free-the-XKB-resource-when-freeing-XkbInterest.patch \
             file://0004-xkb-Prevent-overflow-in-XkbSetCompatMap.patch \
             file://CVE-2026-33999.patch \
+            file://CVE-2026-34000.patch \
             "
 SRC_URI[sha256sum] = "c878d1930d87725d4a5bf498c24f4be8130d5b2646a9fd0f2994deff90116352"