xserver-xorg: Fix for CVE-2025-26596

Upstream-Status: Backport from https://gitlab.freedesktop.org/xorg/xserver/-/commit/80d69f01

(From OE-Core rev: d510d87d9bb3e3489a4482dd0ce66e4bc7622ca0)

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2025-26596.patch

@@ -0,0 +1,49 @@
+From 80d69f01423fc065c950e1ff4e8ddf9f675df773 Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Thu, 28 Nov 2024 11:49:34 +0100
+Subject: [PATCH] xkb: Fix computation of XkbSizeKeySyms
+
+The computation of the length in XkbSizeKeySyms() differs from what is
+actually written in XkbWriteKeySyms(), leading to a heap overflow.
+
+Fix the calculation in XkbSizeKeySyms() to match what kbWriteKeySyms()
+does.
+
+CVE-2025-26596, ZDI-CAN-25543
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
+Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/80d69f01]
+CVE: CVE-2025-26596
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ xkb/xkb.c | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/xkb/xkb.c b/xkb/xkb.c
+index 85659382da..744dba63d7 100644
+--- a/xkb/xkb.c
++++ b/xkb/xkb.c
+@@ -1095,10 +1095,10 @@ XkbSizeKeySyms(XkbDescPtr xkb, xkbGetMapReply * rep)
+     len = rep->nKeySyms * SIZEOF(xkbSymMapWireDesc);
+     symMap = &xkb->map->key_sym_map[rep->firstKeySym];
+     for (i = nSyms = 0; i < rep->nKeySyms; i++, symMap++) {
+-        if (symMap->offset != 0) {
+-            nSymsThisKey = XkbNumGroups(symMap->group_info) * symMap->width;
+-            nSyms += nSymsThisKey;
+-        }
++        nSymsThisKey = XkbNumGroups(symMap->group_info) * symMap->width;
++        if (nSymsThisKey == 0)
++            continue;
++        nSyms += nSymsThisKey;
+     }
+     len += nSyms * 4;
+     rep->totalSyms = nSyms;
+-- 
+GitLab
+

meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.8.bb

@@ -25,6 +25,7 @@ SRC_URI += "file://0001-xf86pciBus.c-use-Intel-ddx-only-for-pre-gen4-hardwar.pat
            file://CVE-2025-26594-1.patch \
            file://CVE-2025-26594-2.patch \
            file://CVE-2025-26595.patch \
+           file://CVE-2025-26596.patch \
            "
 SRC_URI[sha256sum] = "38aadb735650c8024ee25211c190bf8aad844c5f59632761ab1ef4c4d5aeb152"