From: Jan Beulich <jbeulich@suse.com>
Subject: memory: fix off-by-one in XSA-346 change

The comparison against ARRAY_SIZE() needs to be >= in order to avoid
overrunning the pages[] array.

This is XSA-355.

Fixes: 5777a3742d88 ("IOMMU: hold page ref until after deferred TLB flush")
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>

--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -854,7 +854,7 @@ int xenmem_add_to_physmap(struct domain
             ++extra.ppage;
 
         /* Check for continuation if it's not the last iteration. */
-        if ( (++done > ARRAY_SIZE(pages) && extra.ppage) ||
+        if ( (++done >= ARRAY_SIZE(pages) && extra.ppage) ||
              (xatp->size > done && hypercall_preempt_check()) )
         {
             rc = start + done;