diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 1871b8ae83ae..9b28f39bac26 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -462,14 +462,16 @@ static void st_scsi_execute_end(struct request *req, int uptodate)
 {
 	struct st_request *SRpnt = req->end_io_data;
 	struct scsi_tape *STp = SRpnt->stp;
+	struct bio *tmp;
 
 	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
 	STp->buffer->cmdstat.residual = req->resid_len;
 
+	tmp = SRpnt->bio;
 	if (SRpnt->waiting)
 		complete(SRpnt->waiting);
 
-	blk_rq_unmap_user(SRpnt->bio);
+	blk_rq_unmap_user(tmp);
 	__blk_put_request(req->q, req);
 }