From eff3f6cdd398bfac040351e99e64baf3bf64fa2e Mon Sep 17 00:00:00 2001

From: Matthieu Herrb <matthieu@herrb.eu>

Date: Tue, 18 Aug 2020 14:49:04 +0200

Subject: [PATCH xserver] Fix XIChangeHierarchy() integer underflow

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CVE-2020-14346 / ZDI-CAN-11429

This vulnerability was discovered by:

Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>

(cherry picked from commit 1e3392b07923987c6c9d09cf75b24f397b59bd5e)

Signed-off-by: Michel Dänzer <mdaenzer@redhat.com>

---

 Xi/xichangehierarchy.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Xi/xichangehierarchy.c b/Xi/xichangehierarchy.c

index cbdd91258..504defe56 100644

--- a/Xi/xichangehierarchy.c

+++ b/Xi/xichangehierarchy.c

@@ -423,7 +423,7 @@ ProcXIChangeHierarchy(ClientPtr client)

     if (!stuff->num_changes)

         return rc;

-    len = ((size_t)stuff->length << 2) - sizeof(xXIChangeHierarchyReq);

+    len = ((size_t)client->req_len << 2) - sizeof(xXIChangeHierarchyReq);

     any = (xXIAnyHierarchyChangeInfo *) &stuff[1];

     while (stuff->num_changes--) {

-- 

2.28.0