diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index 96d5ad0c1e42..7f636b118287 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -3814,6 +3814,9 @@ static long pmcraid_ioctl_passthrough(
 			rc = -EFAULT;
 			goto out_free_buffer;
 		}
+	} else if (request_size < 0) {
+		rc = -EINVAL;
+		goto out_free_buffer;
 	}
 
 	/* check if we have any additional command parameters */