xwayland: fix CVE-2025-49179

A flaw was found in the X Record extension. The RecordSanityCheckRegisterClients
function does not check for an integer overflow when computing request length,
which allows a client to bypass length checks.

(From OE-Core rev: de28bff9b54b2725d8c06c4760e0ed2b59d3fa61)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 70 insertions, 0 deletions

diff --git a/meta/recipes-graphics/xwayland/xwayland/CVE-2025-49179.patch b/meta/recipes-graphics/xwayland/xwayland/CVE-2025-49179.patch
new file mode 100644
index 0000000000..48c7ed8c13
--- /dev/null
+++ b/meta/recipes-graphics/xwayland/xwayland/CVE-2025-49179.patch
@@ -0,0 +1,69 @@
+From 9d205323894af62b9726fcbaeb5fc69b3c9f61ba Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Mon, 28 Apr 2025 11:47:15 +0200
+Subject: [PATCH]  record: Check for overflow in
+ RecordSanityCheckRegisterClients()
+
+The RecordSanityCheckRegisterClients() checks for the request length,
+but does not check for integer overflow.
+
+A client might send a very large value for either the number of clients
+or the number of protocol ranges that will cause an integer overflow in
+the request length computation, defeating the check for request length.
+
+To avoid the issue, explicitly check the number of clients against the
+limit of clients (which is much lower than an maximum integer value) and
+the number of protocol ranges (multiplied by the record length) do not
+exceed the maximum integer value.
+
+This way, we ensure that the final computation for the request length
+will not overflow the maximum integer limit.
+
+CVE-2025-49179
+
+This issue was discovered by Nils Emmerich <nemmerich@ernw.de> and
+reported by Julian Suleder via ERNW Vulnerability Disclosure.
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
+(cherry picked from commit 2bde9ca49a8fd9a1e6697d5e7ef837870d66f5d4)
+
+Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2026>
+
+CVE: CVE-2025-49179
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/9d205323894af62b9726fcbaeb5fc69b3c9f61ba]
+
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ record/record.c | 8 ++++++++
+ 1 file changed, 8 insertions(+)
+
+diff --git a/record/record.c b/record/record.c
+index e123867..018e53f 100644
+--- a/record/record.c
++++ b/record/record.c
+@@ -45,6 +45,7 @@ and Jim Haggerty of Metheus.
+ #include "inputstr.h"
+ #include "eventconvert.h"
+ #include "scrnintstr.h"
++#include "opaque.h"
+
+ #include <stdio.h>
+ #include <assert.h>
+@@ -1298,6 +1299,13 @@ RecordSanityCheckRegisterClients(RecordContextPtr pContext, ClientPtr client,
+     int i;
+     XID recordingClient;
+
++    /* LimitClients is 2048 at max, way less that MAXINT */
++    if (stuff->nClients > LimitClients)
++        return BadValue;
++
++    if (stuff->nRanges > (MAXINT - 4 * stuff->nClients) / SIZEOF(xRecordRange))
++        return BadValue;
++
+     if (((client->req_len << 2) - SIZEOF(xRecordRegisterClientsReq)) !=
+         4 * stuff->nClients + SIZEOF(xRecordRange) * stuff->nRanges)
+         return BadLength;
+--
+2.40.0
diff --git a/meta/recipes-graphics/xwayland/xwayland_23.2.5.bb b/meta/recipes-graphics/xwayland/xwayland_23.2.5.bb
index e150961882..490e1ca05f 100644
--- a/meta/recipes-graphics/xwayland/xwayland_23.2.5.bb
+++ b/meta/recipes-graphics/xwayland/xwayland_23.2.5.bb
@@ -29,6 +29,7 @@ SRC_URI = "https://www.x.org/archive/individual/xserver/xwayland-${PV}.tar.xz \
            file://CVE-2025-49176-0002.patch \
            file://CVE-2025-49177.patch \
            file://CVE-2025-49178.patch \
+           file://CVE-2025-49179.patch \
 "
 SRC_URI[sha256sum] = "33ec7ff2687a59faaa52b9b09aa8caf118e7ecb6aed8953f526a625ff9f4bd90"