diff --git a/sys/dev/disk/ahci/ahci_cam.c b/sys/dev/disk/ahci/ahci_cam.c
--- a/sys/dev/disk/ahci/ahci_cam.c
+++ b/sys/dev/disk/ahci/ahci_cam.c
@@ -1080,6 +1080,11 @@
 	 * XXX not passing NULL at for direct attach!
 	 */
 	xa = ahci_ata_get_xfer(ap, atx);
+	if (xa == NULL) {
+		ccbh->status = CAM_REQ_CMP_ERR;
+		xpt_done(ccb);
+		return;
+	}
 	rdata = (void *)csio->data_ptr;
 	rdata_len = csio->dxfer_len;
 
@@ -1317,7 +1322,7 @@
 		fis->lba_mid = atp16->lba_mid;
 		fis->lba_mid_exp = atp16->lba_mid_ext;
 		fis->lba_high = atp16->lba_high;
-		fis->lba_mid_exp = atp16->lba_mid_ext;
+		fis->lba_high_exp = atp16->lba_high_ext;
 		fis->device = atp16->device;	/* maybe always 0? */
 		fis->command = atp16->command;