IB/iser: Fix wrong calculation of protection buffer length

commit a065fe6a upstream.

This length miss-calculation may cause a silent data corruption
in the DIX case and cause the device to reference unmapped area.

Fixes: d77e6535 ('libiscsi, iser: Adjust data_length to include protection information')
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/infiniband/ulp/iser/iser_initiator.c

@@ -402,8 +402,8 @@ int iser_send_command(struct iscsi_conn *conn,
 	if (scsi_prot_sg_count(sc)) {
 		prot_buf->buf  = scsi_prot_sglist(sc);
 		prot_buf->size = scsi_prot_sg_count(sc);
-		prot_buf->data_len = data_buf->data_len >>
-				     ilog2(sc->device->sector_size) * 8;
+		prot_buf->data_len = (data_buf->data_len >>
+				     ilog2(sc->device->sector_size)) * 8;
 	}
 
 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {