[scarthgap,3/5] xserver-xorg: Fix CVE-2026-34001

diff --git a/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2026-34001.patch b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2026-34001.patch
new file mode 100644
index 0000000000..a438f5ffcd
--- /dev/null
+++ b/meta/recipes-graphics/xorg-xserver/xserver-xorg/CVE-2026-34001.patch
@@ -0,0 +1,104 @@ 
+From f19ab94ba9c891d801231654267556dc7f32b5e0 Mon Sep 17 00:00:00 2001
+From: Olivier Fourdan <ofourdan@redhat.com>
+Date: Wed, 18 Feb 2026 16:23:23 +0100
+Subject: [PATCH] miext/sync: Fix use-after-free in miSyncTriggerFence()
+
+As reported by valgrind:
+
+  == Invalid read of size 8
+  ==    at 0x568C14: miSyncTriggerFence (misync.c:140)
+  ==    by 0x540688: ProcSyncTriggerFence (sync.c:1957)
+  ==    by 0x540CCC: ProcSyncDispatch (sync.c:2152)
+  ==    by 0x4A28C5: Dispatch (dispatch.c:553)
+  ==    by 0x4B0B24: dix_main (main.c:274)
+  ==    by 0x42915E: main (stubmain.c:34)
+  ==  Address 0x17e35488 is 8 bytes inside a block of size 16 free'd
+  ==    at 0x4843E43: free (vg_replace_malloc.c:990)
+  ==    by 0x53D683: SyncDeleteTriggerFromSyncObject (sync.c:169)
+  ==    by 0x53F14D: FreeAwait (sync.c:1208)
+  ==    by 0x4DFB06: doFreeResource (resource.c:888)
+  ==    by 0x4DFC59: FreeResource (resource.c:918)
+  ==    by 0x53E349: SyncAwaitTriggerFired (sync.c:701)
+  ==    by 0x568C52: miSyncTriggerFence (misync.c:142)
+  ==    by 0x540688: ProcSyncTriggerFence (sync.c:1957)
+  ==    by 0x540CCC: ProcSyncDispatch (sync.c:2152)
+  ==    by 0x4A28C5: Dispatch (dispatch.c:553)
+  ==    by 0x4B0B24: dix_main (main.c:274)
+  ==    by 0x42915E: main (stubmain.c:34)
+  ==  Block was alloc'd at
+  ==    at 0x4840B26: malloc (vg_replace_malloc.c:447)
+  ==    by 0x5E50E1: XNFalloc (utils.c:1129)
+  ==    by 0x53D772: SyncAddTriggerToSyncObject (sync.c:206)
+  ==    by 0x53DCA8: SyncInitTrigger (sync.c:414)
+  ==    by 0x5409C7: ProcSyncAwaitFence (sync.c:2089)
+  ==    by 0x540D04: ProcSyncDispatch (sync.c:2160)
+  ==    by 0x4A28C5: Dispatch (dispatch.c:553)
+  ==    by 0x4B0B24: dix_main (main.c:274)
+  ==    by 0x42915E: main (stubmain.c:34)
+
+When walking the list of fences to trigger, miSyncTriggerFence() may
+call TriggerFence() for the current trigger, which end up calling the
+function SyncAwaitTriggerFired().
+
+SyncAwaitTriggerFired() frees the entire await resource, which removes
+all triggers from that await - including pNext which may be another
+trigger from the same await attached to the same fence.
+
+On the next iteration, ptl = pNext points to freed memory...
+
+To avoid the issue, we need to restart the iteration from the beginning
+of the list each time a trigger fires, since the callback can modify the
+list.
+
+CVE-2026-34001, ZDI-CAN-28706
+
+This vulnerability was discovered by:
+Jan-Niklas Sohn working with TrendAI Zero Day Initiative
+
+Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
+Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
+Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
+
+Upstream-Status: Backport [https://gitlab.freedesktop.org/xorg/xserver/-/commit/f19ab94ba9c891d801231654267556dc7f32b5e0]
+CVE: CVE-2026-34001
+Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
+---
+ miext/sync/misync.c | 18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+diff --git a/miext/sync/misync.c b/miext/sync/misync.c
+index 0931803..e11eba2 100644
+--- a/miext/sync/misync.c
++++ b/miext/sync/misync.c
+@@ -131,16 +131,22 @@ miSyncDestroyFence(SyncFence * pFence)
+ void
+ miSyncTriggerFence(SyncFence * pFence)
+ {
+-    SyncTriggerList *ptl, *pNext;
++    SyncTriggerList *ptl;
++    Bool triggered;
+ 
+     pFence->funcs.SetTriggered(pFence);
+ 
+     /* run through triggers to see if any fired */
+-    for (ptl = pFence->sync.pTriglist; ptl; ptl = pNext) {
+-        pNext = ptl->next;
+-        if ((*ptl->pTrigger->CheckTrigger) (ptl->pTrigger, 0))
+-            (*ptl->pTrigger->TriggerFired) (ptl->pTrigger);
+-    }
++    do {
++	triggered = FALSE;
++	for (ptl = pFence->sync.pTriglist; ptl; ptl = ptl->next) {
++	    if ((*ptl->pTrigger->CheckTrigger) (ptl->pTrigger, 0)) {
++                (*ptl->pTrigger->TriggerFired) (ptl->pTrigger);
++		triggered = TRUE;
++		break;
++	    }
++        }
++    } while (triggered);
+ }
+ 
+ SyncScreenFuncsPtr
+-- 
+2.43.0
+
diff --git a/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.18.bb b/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.18.bb
index 658a608b5e..dfed2c2437 100644
--- a/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.18.bb
+++ b/meta/recipes-graphics/xorg-xserver/xserver-xorg_21.1.18.bb
@@ -7,6 +7,7 @@  SRC_URI += "file://0001-xf86pciBus.c-use-Intel-ddx-only-for-pre-gen4-hardwar.pat
             file://0004-xkb-Prevent-overflow-in-XkbSetCompatMap.patch \
             file://CVE-2026-33999.patch \
             file://CVE-2026-34000.patch \
+            file://CVE-2026-34001.patch \
             "
 SRC_URI[sha256sum] = "c878d1930d87725d4a5bf498c24f4be8130d5b2646a9fd0f2994deff90116352"