xserver-xorg: Fix for CVE-2025-62231

Upstream-Status: Backport from https://gitlab.freedesktop.org/xorg/xserver/-/commit/3baad99f9c15028ed8c3e3d8408e5ec35db155aa

(From OE-Core rev: 05fe08caa0d4bd30510b496a300731a9754f24b8)

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

2 files changed, 54 insertions, 0 deletions

diff --git a/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2025-62231.patch b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2025-62231.patch
new file mode 100644
index 0000000000..4bcf362531
--- /dev/null
+++ b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2025-62231.patch
@@ -0,0 +1,53 @@
+From 3baad99f9c15028ed8c3e3d8408e5ec35db155aa Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Wed, 10 Sep 2025 16:30:29 +0200
+Subject: [PATCH] xkb: Prevent overflow in XkbSetCompatMap()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The XkbCompatMap structure stores its "num_si" and "size_si" fields
+using an unsigned short.
+
+However, the function _XkbSetCompatMap() will store the sum of the
+input data "firstSI" and "nSI" in both XkbCompatMap's "num_si" and
+"size_si" without first checking if the sum overflows the maximum
+unsigned short value, leading to a possible overflow.
+
+To avoid the issue, check whether the sum does not exceed the maximum
+unsigned short value, or return a "BadValue" error otherwise.
+
+CVE-2025-62231, ZDI-CAN-27560
+
+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: Michel Dänzer <mdaenzer@redhat.com>
+(cherry picked from commit 475d9f49acd0e55bc0b089ed77f732ad18585470)
+
+Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2087>
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/3baad99f9c15028ed8c3e3d8408e5ec35db155aa]
+CVE: CVE-2025-62231
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ xkb/xkb.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/xkb/xkb.c b/xkb/xkb.c
+index 26d965d482..137d70da27 100644
+--- a/xkb/xkb.c
++++ b/xkb/xkb.c
+@@ -2992,6 +2992,8 @@ _XkbSetCompatMap(ClientPtr client, DeviceIntPtr dev,
+         XkbSymInterpretPtr sym;
+         unsigned int skipped = 0;
+ 
++        if ((unsigned) (req->firstSI + req->nSI) > USHRT_MAX)
++            return BadValue;
+         if ((unsigned) (req->firstSI + req->nSI) > compat->size_si) {
+             compat->num_si = compat->size_si = req->firstSI + req->nSI;
+             compat->sym_interpret = reallocarray(compat->sym_interpret,
+-- 
+GitLab
+
diff --git a/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.8.bb b/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.8.bb
index ed543f6270..1d486fc0bc 100644
--- a/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.8.bb
+++ b/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.8.bb
@@ -47,6 +47,7 @@ SRC_URI += "file://0001-xf86pciBus.c-use-Intel-ddx-only-for-pre-gen4-hardwar.pat
            file://CVE-2025-62229.patch \
            file://CVE-2025-62230-1.patch \
            file://CVE-2025-62230-2.patch \
+           file://CVE-2025-62231.patch \
            "
 SRC_URI[sha256sum] = "38aadb735650c8024ee25211c190bf8aad844c5f59632761ab1ef4c4d5aeb152"