1 files changed, 102 insertions, 0 deletions

diff --git a/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2023-5380.patch b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2023-5380.patch
new file mode 100644
index 0000000000..720340d83b
--- /dev/null
+++ b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2023-5380.patch
@@ -0,0 +1,102 @@
+From 564ccf2ce9616620456102727acb8b0256b7bbd7 Mon Sep 17 00:00:00 2001
+From: Peter Hutterer <peter.hutterer@who-t.net>
+Date: Thu, 5 Oct 2023 12:19:45 +1000
+Subject: [PATCH] mi: reset the PointerWindows reference on screen switch
+
+PointerWindows[] keeps a reference to the last window our sprite
+entered - changes are usually handled by CheckMotion().
+
+If we switch between screens via XWarpPointer our
+dev->spriteInfo->sprite->win is set to the new screen's root window.
+If there's another window at the cursor location CheckMotion() will
+trigger the right enter/leave events later. If there is not, it skips
+that process and we never trigger LeaveWindow() - PointerWindows[] for
+the device still refers to the previous window.
+
+If that window is destroyed we have a dangling reference that will
+eventually cause a use-after-free bug when checking the window hierarchy
+later.
+
+To trigger this, we require:
+- two protocol screens
+- XWarpPointer to the other screen's root window
+- XDestroyWindow before entering any other window
+
+This is a niche bug so we hack around it by making sure we reset the
+PointerWindows[] entry so we cannot have a dangling pointer. This
+doesn't handle Enter/Leave events correctly but the previous code didn't
+either.
+
+CVE-2023-5380, ZDI-CAN-21608
+
+This vulnerability was discovered by:
+Sri working with Trend Micro Zero Day Initiative
+
+Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
+Reviewed-by: Adam Jackson <ajax@redhat.com>
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/564ccf2ce9616620456102727acb8b0256b7bbd7]
+CVE: CVE-2023-5380
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ dix/enterleave.h   |  2 --
+ include/eventstr.h |  3 +++
+ mi/mipointer.c     | 17 +++++++++++++++--
+ 3 files changed, 18 insertions(+), 4 deletions(-)
+
+diff --git a/dix/enterleave.h b/dix/enterleave.h
+index 4b833d8..e8af924 100644
+--- a/dix/enterleave.h
++++ b/dix/enterleave.h
+@@ -58,8 +58,6 @@ extern void DeviceFocusEvent(DeviceIntPtr dev,
+ 
+ extern void EnterWindow(DeviceIntPtr dev, WindowPtr win, int mode);
+ 
+-extern void LeaveWindow(DeviceIntPtr dev);
+-
+ extern void CoreFocusEvent(DeviceIntPtr kbd,
+                            int type, int mode, int detail, WindowPtr pWin);
+ 
+diff --git a/include/eventstr.h b/include/eventstr.h
+index bf3b95f..2bae3b0 100644
+--- a/include/eventstr.h
++++ b/include/eventstr.h
+@@ -296,4 +296,7 @@ union _InternalEvent {
+ #endif
+ };
+ 
++extern void
++LeaveWindow(DeviceIntPtr dev);
++
+ #endif
+diff --git a/mi/mipointer.c b/mi/mipointer.c
+index 75be1ae..b12ae9b 100644
+--- a/mi/mipointer.c
++++ b/mi/mipointer.c
+@@ -397,8 +397,21 @@ miPointerWarpCursor(DeviceIntPtr pDev, ScreenPtr pScreen, int x, int y)
+ #ifdef PANORAMIX
+         && noPanoramiXExtension
+ #endif
+-        )
+-        UpdateSpriteForScreen(pDev, pScreen);
++        ) {
++            DeviceIntPtr master = GetMaster(pDev, MASTER_POINTER);
++            /* Hack for CVE-2023-5380: if we're moving
++             * screens PointerWindows[] keeps referring to the
++             * old window. If that gets destroyed we have a UAF
++             * bug later. Only happens when jumping from a window
++             * to the root window on the other screen.
++             * Enter/Leave events are incorrect for that case but
++             * too niche to fix.
++             */
++            LeaveWindow(pDev);
++            if (master)
++                LeaveWindow(master);
++            UpdateSpriteForScreen(pDev, pScreen);
++    }
+ }
+ 
+ /**
+-- 
+2.25.1
+