File 5fbd042b-memory-off-by-one-in-XSA-346.patch of Package xen.17645

# Commit 9b156bcc3ffcc7949edd4460b718a241e87ae302
# Date 2020-11-24 14:01:31 +0100
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
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
@@ -853,7 +853,7 @@ 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;