From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91DDCC33CAC for ; Mon, 3 Feb 2020 12:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 649992082E for ; Mon, 3 Feb 2020 12:16:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=st.com header.i=@st.com header.b="akmyOYhf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727898AbgBCMQk (ORCPT ); Mon, 3 Feb 2020 07:16:40 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:20008 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727783AbgBCMQk (ORCPT ); Mon, 3 Feb 2020 07:16:40 -0500 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 013CEBua002580; Mon, 3 Feb 2020 13:16:27 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=st.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=STMicroelectronics; bh=tRyeAl3e8NEmD+QHaO3MeWwtme06WG9UkinpQDoXHFY=; b=akmyOYhff2JPsD+A4MYUaTNr2KbkzIN6jXi1sosouRRZ95+9bOe3dbjslwDFLmtQlDFB 85N1wiklXjjzt3dz0XRXbdbTApB2YlgEQ0cave8rHnXKc26LvNVre7mVuqGpq4RjymPL opFQSBJVMteuXrBsJ3T1sj07/OKd05Fv0Qyu+kph713O/SR6e0wT/7HZJUY0zgR85og5 0xikAz9HEC6DluG3xKruepWI3Pwe1OV5hxKfchTw5kmtz2dzT0lCfGoRi0ItJIRMa71e XxCPUnWI3oNRoY4xgzOxiWoucu7I+yVsvcePYg1FYns3BLdttyzn7971ZuwEoT2aMMJG xA== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2xvybds9qv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 03 Feb 2020 13:16:27 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id A713C100034; Mon, 3 Feb 2020 13:16:22 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag3node3.st.com [10.75.127.9]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 72D072125DA; Mon, 3 Feb 2020 13:16:22 +0100 (CET) Received: from localhost (10.75.127.44) by SFHDAG3NODE3.st.com (10.75.127.9) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Mon, 3 Feb 2020 13:16:21 +0100 From: Benjamin Gaignard To: , , , CC: , , Benjamin Gaignard , , Subject: [PATCH] drm/dp_mst: Check crc4 value while building sideband message Date: Mon, 3 Feb 2020 13:16:20 +0100 Message-ID: <20200203121620.9002-1-benjamin.gaignard@st.com> X-Mailer: git-send-email 2.15.0 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.75.127.44] X-ClientProxiedBy: SFHDAG1NODE1.st.com (10.75.127.1) To SFHDAG3NODE3.st.com (10.75.127.9) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-02-03_03:2020-02-02,2020-02-03 signatures=0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Check that computed crc value is matching the one encoded in the message. Signed-off-by: Benjamin Gaignard --- CC: lyude@redhat.com CC: airlied@linux.ie CC: jani.nikula@linux.intel.com drivers/gpu/drm/drm_dp_mst_topology.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 822d2f177f90..eee899d6742b 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -736,6 +736,10 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg, if (msg->curchunk_idx >= msg->curchunk_len) { /* do CRC */ crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); + if (crc4 != msg->chunk[msg->curchunk_len - 1]) + print_hex_dump(KERN_DEBUG, "wrong crc", + DUMP_PREFIX_NONE, 16, 1, + msg->chunk, msg->curchunk_len, false); /* copy chunk into bigger msg */ memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); msg->curlen += msg->curchunk_len - 1; -- 2.15.0