diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 895eaa25807c..f9bce818da11 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -1286,7 +1286,8 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
 		return -EOPNOTSUPP;
 	if (mem.nregions > max_mem_regions)
 		return -E2BIG;
-	newmem = kvzalloc(size + mem.nregions * sizeof(*m->regions), GFP_KERNEL);
+	newmem = kvzalloc(struct_size(newmem, regions, mem.nregions),
+			GFP_KERNEL);
 	if (!newmem)
 		return -ENOMEM;