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=-2.6 required=3.0 tests=BIGNUM_EMAILS,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT 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 9096CC282C4 for ; Tue, 12 Feb 2019 12:48:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 552172084E for ; Tue, 12 Feb 2019 12:48:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="bGhF/T7e" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728126AbfBLMs6 (ORCPT ); Tue, 12 Feb 2019 07:48:58 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:55722 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725916AbfBLMs6 (ORCPT ); Tue, 12 Feb 2019 07:48:58 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x1CCmuqj119009; Tue, 12 Feb 2019 12:48:56 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2018-07-02; bh=3JJzCTXinBco2WLD25+8KZK/QsA/9DHZ5ZsZEZDyuzY=; b=bGhF/T7e9ZSgdAbceKag3pghk5IdxIq3QmO64PrbltCR5b7l6S6eeoydKf6ysIPldxII LsCAkXoiCmL/+eLfhjYsTAl2t1mtvAByjQwWm4I+9ERwjXQNG4FngFBXxd3qOdH7jDT5 2ocJznpAPwayUoVuuv5HFapSM2jXph3SHED+xY7auh2Yg+JXqHc+x+V9aNjhoOMFGYqZ iWgvNY9iXoMl2hPJkpGmvpxJFI9DxI1kW1nXz+lYMoKuGM6i0FdSgHTOE/C+xICl4sO/ tRcbHmnfenb4CPWQ3IkIZNu72wIlxImpm8S0x+ca6wJFUHiYIX4DJ7O8o6+awG3ywlho 2A== Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp2130.oracle.com with ESMTP id 2qhrekbmk6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Feb 2019 12:48:56 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userv0021.oracle.com (8.14.4/8.14.4) with ESMTP id x1CCmtQQ008049 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Feb 2019 12:48:55 GMT Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x1CCmsHI002862; Tue, 12 Feb 2019 12:48:55 GMT Received: from kadam (/41.202.241.35) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 Feb 2019 04:48:54 -0800 Date: Tue, 12 Feb 2019 15:48:47 +0300 From: Dan Carpenter To: pboettcher@kernellabs.com Cc: linux-media@vger.kernel.org Subject: [bug report] [media] dib8000: potential off by one Message-ID: <20190212124847.GA11184@kadam> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9164 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=963 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902120094 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hello Patrick Boettcher, The patch 173a64cb3fcf: "[media] dib8000: enhancement" from Apr 22, 2013, leads to the following static checker warning: drivers/media/dvb-frontends/dib8000.c:2132 dib8000_get_init_prbs() error: buffer overflow 'lut_prbs_2k' 14 <= 14 drivers/media/dvb-frontends/dib8000.c 2123 static u16 dib8000_get_init_prbs(struct dib8000_state *state, u16 subchannel) 2124 { 2125 int sub_channel_prbs_group = 0; 2126 2127 sub_channel_prbs_group = (subchannel / 3) + 1; 2128 dprintk("sub_channel_prbs_group = %d , subchannel =%d prbs = 0x%04x\n", sub_channel_prbs_group, subchannel, lut_prbs_8k[sub_channel_prbs_group]); 2129 2130 switch (state->fe[0]->dtv_property_cache.transmission_mode) { 2131 case TRANSMISSION_MODE_2K: --> 2132 return lut_prbs_2k[sub_channel_prbs_group]; 2133 case TRANSMISSION_MODE_4K: 2134 return lut_prbs_4k[sub_channel_prbs_group]; 2135 default: 2136 case TRANSMISSION_MODE_8K: 2137 return lut_prbs_8k[sub_channel_prbs_group]; 2138 } 2139 } [ snip ] 3305 break; 3306 3307 case CT_DEMOD_STEP_11: /* 41 : init prbs autosearch */ 3308 if (state->subchannel <= 41) { ^^^^^^^^^^^^^^^^^^^^^^^ The problem is here. If ->subchannel is 41 then we are off by one. In the original code this was something like state->subchannel % 41 so I suspect the fix is to change <= to just < but I'm not totally sure. 3309 dib8000_set_subchannel_prbs(state, dib8000_get_init_prbs(state, state->subchannel)); 3310 *tune_state = CT_DEMOD_STEP_9; 3311 } else { 3312 *tune_state = CT_DEMOD_STOP; 3313 state->status = FE_STATUS_TUNE_FAILED; 3314 } 3315 break; 3316 3317 default: 3318 break; 3319 } regards, dan carpenter