1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c
index 3c4c58b9fe76..3b6fb5b3bdb2 100644
--- a/drivers/net/xen-netback/hash.c
+++ b/drivers/net/xen-netback/hash.c
@@ -332,20 +332,22 @@ u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size)
 u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len,
                             u32 off)
 {
-        u32 *mapping = &vif->hash.mapping[off];
+        u32 *mapping = vif->hash.mapping;
         struct gnttab_copy copy_op = {
                 .source.u.ref = gref,
                 .source.domid = vif->domid,
-                .dest.u.gmfn = virt_to_gfn(mapping),
                 .dest.domid = DOMID_SELF,
-                .dest.offset = xen_offset_in_page(mapping),
-                .len = len * sizeof(u32),
+                .len = len * sizeof(*mapping),
                 .flags = GNTCOPY_source_gref
         };
 
-        if ((off + len > vif->hash.size) || copy_op.len > XEN_PAGE_SIZE)
+        if ((off + len < off) || (off + len > vif->hash.size) ||
+            len > XEN_PAGE_SIZE / sizeof(*mapping))
                 return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;
 
+        copy_op.dest.u.gmfn = virt_to_gfn(mapping + off);
+        copy_op.dest.offset = xen_offset_in_page(mapping + off);
+
         while (len-- != 0)
                 if (mapping[off++] >= vif->num_queues)
                         return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER;