From fec1c620d9903766b01f802e871cc1eecb039b5f Mon Sep 17 00:00:00 2001
From: Ian Jackson <Ian.Jackson@eu.citrix.com>
Date: Wed, 5 Sep 2012 12:29:05 +0100
Subject: xen: Don't BUG_ON() PoD operations on a non-translated guest.

This is XSA-14 / CVE-2012-3496

Signed-off-by: Tim Deegan <tim@xen.org>
Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Ian Campbell <ian.campbell@citrix.com>
---
 xen/arch/x86/mm/p2m.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 787b4be6a3..54940338d2 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2058,7 +2058,8 @@ guest_physmap_mark_populate_on_demand(struct domain *d, unsigned long gfn,
     int pod_count = 0;
     int rc = 0;
 
-    BUG_ON(!paging_mode_translate(d));
+    if ( !paging_mode_translate(d) )
+        return -EINVAL;
 
     rc = gfn_check_limit(d, gfn, order);
     if ( rc != 0 )
-- 
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