$NetBSD: patch-CVE-2015-8339,v 1.1 2016/01/07 17:55:55 bouyer Exp $

Patch for CVE-2015-8339 and CVE-2015-8340 aka XSA-159, based on
http://xenbits.xenproject.org/xsa/xsa159.patch

--- xen/common/memory.c.orig	2013-09-10 08:42:18.000000000 +0200
+++ xen/common/memory.c	2016-01-07 14:39:42.000000000 +0100
@@ -487,7 +487,11 @@
     /* Reassign any input pages we managed to steal. */
     while ( (page = page_list_remove_head(&in_chunk_list)) )
         if ( assign_pages(d, page, 0, MEMF_no_refcount) )
-            BUG();
+	{
+            BUG_ON(!d->is_dying);
+	    if ( test_and_clear_bit(_PGC_allocated, &page->count_info) )
+		put_page(page);
+	}
  dying:
     rcu_unlock_domain(d);
     /* Free any output pages we managed to allocate. */