diff --git a/sys/dev/sec/sec.c b/sys/dev/sec/sec.c
index 342ee849aa2b..6af560e9bbb2 100644
--- a/sys/dev/sec/sec.c
+++ b/sys/dev/sec/sec.c
@@ -852,7 +852,7 @@ sec_desc_map_dma(struct sec_softc *sc, struct sec_dma_mem *dma_mem,
 		size = m_length(crp->crp_buf.cb_mbuf, NULL);
 		break;
 	case CRYPTO_BUF_VMPAGE:
-		size = PAGE_SIZE - cb->cb_vm_page_offset;
+		size = PAGE_SIZE - crp->crp_buf.cb_vm_page_offset;
 		break;
 	default:
 		return (EINVAL);