From ccdd431cd8f1cabae9d744f0514b6533c438908c Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Mon, 5 Dec 2022 15:55:54 +1000
Subject: [PATCH] xkb: reset the radio_groups pointer to NULL after freeing it

Unlike other elements of the keymap, this pointer was freed but not
reset. On a subsequent XkbGetKbdByName request, the server may access
already freed memory.

CVE-2022-4283, ZDI-CAN-19530

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
---
 xkb/xkbUtils.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/xkb/xkbUtils.c b/xkb/xkbUtils.c
index dd089c204..3f5791a18 100644
--- a/xkb/xkbUtils.c
+++ b/xkb/xkbUtils.c
@@ -1326,6 +1326,7 @@ _XkbCopyNames(XkbDescPtr src, XkbDescPtr dst)
         }
         else {
             free(dst->names->radio_groups);
+            dst->names->radio_groups = NULL;
         }
         dst->names->num_rg = src->names->num_rg;
 
-- 
GitLab