1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 1afd5690858c..9ef54ebc1194 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -455,6 +455,8 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
         unsigned long mfn;
 
         ret = HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, map_ops, count);
+        if (ret)
+                return ret;
 
         for (i = 0; i < count; i++) {
                 /* m2p override only supported for GNTMAP_contains_pte mappings */
@@ -463,7 +465,9 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
                 pte = (pte_t *) (mfn_to_virt(PFN_DOWN(map_ops[i].host_addr)) +
                                 (map_ops[i].host_addr & ~PAGE_MASK));
                 mfn = pte_mfn(*pte);
-                m2p_add_override(mfn, pages[i]);
+                ret = m2p_add_override(mfn, pages[i]);
+                if (ret)
+                        return ret;
         }
 
         return ret;
@@ -476,8 +480,14 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
         int i, ret;
 
         ret = HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, unmap_ops, count);
-        for (i = 0; i < count; i++)
-                m2p_remove_override(pages[i]);
+        if (ret)
+                return ret;
+
+        for (i = 0; i < count; i++) {
+                ret = m2p_remove_override(pages[i]);
+                if (ret)
+                        return ret;
+        }
 
         return ret;
 }