You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
xorg-x11-server/SOURCES/0005-Xext-free-the-screen-s...

49 lines
1.6 KiB

From 6b59bdddf30dde413c4e0391cf84f3b94d4b4e31 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Tue, 29 Nov 2022 14:53:07 +1000
Subject: [PATCH xserver 5/7] Xext: free the screen saver resource when
replacing it
This fixes a use-after-free bug:
When a client first calls ScreenSaverSetAttributes(), a struct
ScreenSaverAttrRec is allocated and added to the client's
resources.
When the same client calls ScreenSaverSetAttributes() again, a new
struct ScreenSaverAttrRec is allocated, replacing the old struct. The
old struct was freed but not removed from the clients resources.
Later, when the client is destroyed the resource system invokes
ScreenSaverFreeAttr and attempts to clean up the already freed struct.
Fix this by letting the resource system free the old attrs instead.
CVE-2022-46343, ZDI-CAN 19404
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>
---
Xext/saver.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/Xext/saver.c b/Xext/saver.c
index f813ba08d1..fd6153c313 100644
--- a/Xext/saver.c
+++ b/Xext/saver.c
@@ -1051,7 +1051,7 @@ ScreenSaverSetAttributes(ClientPtr client)
pVlist++;
}
if (pPriv->attr)
- FreeScreenAttr(pPriv->attr);
+ FreeResource(pPriv->attr->resource, AttrType);
pPriv->attr = pAttr;
pAttr->resource = FakeClientID(client->index);
if (!AddResource(pAttr->resource, AttrType, (void *) pAttr))
--
2.38.1