Fix for CVE-2023-1393

Resolves: rhbz#2180299
This commit is contained in:
Olivier Fourdan 2023-03-31 16:43:08 +02:00
parent f253e3a542
commit b1de33e148
2 changed files with 48 additions and 1 deletions

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@ -0,0 +1,42 @@
From 26ef545b3502f61ca722a7a3373507e88ef64110 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Mon, 13 Mar 2023 11:08:47 +0100
Subject: [PATCH xserver] composite: Fix use-after-free of the COW
ZDI-CAN-19866/CVE-2023-1393
If a client explicitly destroys the compositor overlay window (aka COW),
we would leave a dangling pointer to that window in the CompScreen
structure, which will trigger a use-after-free later.
Make sure to clear the CompScreen pointer to the COW when the latter gets
destroyed explicitly by the client.
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: Adam Jackson <ajax@redhat.com>
---
composite/compwindow.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/composite/compwindow.c b/composite/compwindow.c
index 4e2494b86..b30da589e 100644
--- a/composite/compwindow.c
+++ b/composite/compwindow.c
@@ -620,6 +620,11 @@ compDestroyWindow(WindowPtr pWin)
ret = (*pScreen->DestroyWindow) (pWin);
cs->DestroyWindow = pScreen->DestroyWindow;
pScreen->DestroyWindow = compDestroyWindow;
+
+ /* Did we just destroy the overlay window? */
+ if (pWin == cs->pOverlayWin)
+ cs->pOverlayWin = NULL;
+
/* compCheckTree (pWin->drawable.pScreen); can't check -- tree isn't good*/
return ret;
}
--
2.40.0

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@ -9,7 +9,7 @@
Summary: Xwayland
Name: xorg-x11-server-Xwayland
Version: 21.1.3
Release: 7%{?gitdate:.%{gitdate}git%{shortcommit}}%{?dist}
Release: 8%{?gitdate:.%{gitdate}git%{shortcommit}}%{?dist}
URL: http://www.x.org
%if 0%{?gitdate}
@ -57,6 +57,8 @@ Patch10016: 0007-xkb-reset-the-radio_groups-pointer-to-NULL-after-fre.patch
Patch10017: 0008-Xext-fix-invalid-event-type-mask-in-XTestSwapFakeInp.patch
# CVE-2023-0494
Patch10018: 0001-Xi-fix-potential-use-after-free-in-DeepCopyPointerCl.patch
# CVE-2023-1393
Patch10019: 0001-composite-Fix-use-after-free-of-the-COW.patch
License: MIT
@ -163,6 +165,9 @@ rm -Rf $RPM_BUILD_ROOT%{_localstatedir}/lib/xkb
%{_libdir}/pkgconfig/xwayland.pc
%changelog
* Fri Mar 31 2023 Olivier Fourdan <ofourdan@redhat.com> - 21.1.3-8
- Fix CVE-2023-1393 (#2180299)
* Tue Feb 7 2023 Olivier Fourdan <ofourdan@redhat.com> - 21.1.3-7
- Fix CVE-2023-0494 (#2166974)