diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index c24bb690680b4104d6621c5b984d869f51af2cd3..e7e3ae13516d7d69f37724cf5c5ce9c2b7790f51 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -964,7 +964,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 				prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
 			}
 			/*
-			 * Set prot_iter to data_iter, and advance past any
+			 * Set prot_iter to data_iter and truncate it to
+			 * prot_bytes, and advance data_iter past any
 			 * preceeding prot_bytes that may be present.
 			 *
 			 * Also fix up the exp_data_len to reflect only the
@@ -973,6 +974,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
 			if (prot_bytes) {
 				exp_data_len -= prot_bytes;
 				prot_iter = data_iter;
+				iov_iter_truncate(&prot_iter, prot_bytes);
 				iov_iter_advance(&data_iter, prot_bytes);
 			}
 			tag = vhost64_to_cpu(vq, v_req_pi.tag);