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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 E8B37C43381 for ; Sun, 3 Mar 2019 10:06:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B73620836 for ; Sun, 3 Mar 2019 10:06:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="UHZH84ki" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726133AbfCCKF7 (ORCPT ); Sun, 3 Mar 2019 05:05:59 -0500 Received: from nbd.name ([46.4.11.11]:47036 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726032AbfCCKF6 (ORCPT ); Sun, 3 Mar 2019 05:05:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=9oBiZti/vu20O3nlFR+6+BgWj3kr/MO2+a3u5axqI6Y=; b=UHZH84kiliwO1BLeismm5Xbjwf N6tI550Fkn10VvhD4togf7dXv/d1H2/vO3X/AmtsKc46adLwKHlWiEQR6C0rQYqerOIF7FTeg+RV6 h9j96Y5W2eBbDUz8n9EAFuLsivRBzrO5v2zd325TRufyrStDt4cb3DWNV2g5UpBMwYoo=; Subject: Re: [mt76/mt7603/mac] Question about missing variable assignment To: "Gustavo A. R. Silva" , Lorenzo Bianconi , Kalle Valo , "David S. Miller" , Matthias Brugger Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org References: <20190302211046.GA20268@embeddedor.com> From: Felix Fietkau Openpgp: preference=signencrypt Autocrypt: addr=nbd@nbd.name; prefer-encrypt=mutual; keydata= mQGiBEah5CcRBADIY7pu4LIv3jBlyQ/2u87iIZGe6f0f8pyB4UjzfJNXhJb8JylYYRzIOSxh ExKsdLCnJqsG1PY1mqTtoG8sONpwsHr2oJ4itjcGHfn5NJSUGTbtbbxLro13tHkGFCoCr4Z5 Pv+XRgiANSpYlIigiMbOkide6wbggQK32tC20QxUIwCg4k6dtV/4kwEeiOUfErq00TVqIiEE AKcUi4taOuh/PQWx/Ujjl/P1LfJXqLKRPa8PwD4j2yjoc9l+7LptSxJThL9KSu6gtXQjcoR2 vCK0OeYJhgO4kYMI78h1TSaxmtImEAnjFPYJYVsxrhay92jisYc7z5R/76AaELfF6RCjjGeP wdalulG+erWju710Bif7E1yjYVWeA/9Wd1lsOmx6uwwYgNqoFtcAunDaMKi9xVQW18FsUusM TdRvTZLBpoUAy+MajAL+R73TwLq3LnKpIcCwftyQXK5pEDKq57OhxJVv1Q8XkA9Dn1SBOjNB l25vJDFAT9ntp9THeDD2fv15yk4EKpWhu4H00/YX8KkhFsrtUs69+vZQwbQcRmVsaXggRmll dGthdSA8bmJkQG5iZC5uYW1lPohgBBMRAgAgBQJGoeQnAhsjBgsJCAcDAgQVAggDBBYCAwEC HgECF4AACgkQ130UHQKnbvXsvgCgjsAIIOsY7xZ8VcSm7NABpi91yTMAniMMmH7FRenEAYMa VrwYTIThkTlQuQINBEah5FQQCACMIep/hTzgPZ9HbCTKm9xN4bZX0JjrqjFem1Nxf3MBM5vN CYGBn8F4sGIzPmLhl4xFeq3k5irVg/YvxSDbQN6NJv8o+tP6zsMeWX2JjtV0P4aDIN1pK2/w VxcicArw0VYdv2ZCarccFBgH2a6GjswqlCqVM3gNIMI8ikzenKcso8YErGGiKYeMEZLwHaxE Y7mTPuOTrWL8uWWRL5mVjhZEVvDez6em/OYvzBwbkhImrryF29e3Po2cfY2n7EKjjr3/141K DHBBdgXlPNfDwROnA5ugjjEBjwkwBQqPpDA7AYPvpHh5vLbZnVGu5CwG7NAsrb2isRmjYoqk wu++3117AAMFB/9S0Sj7qFFQcD4laADVsabTpNNpaV4wAgVTRHKV/kC9luItzwDnUcsZUPdQ f3MueRJ3jIHU0UmRBG3uQftqbZJj3ikhnfvyLmkCNe+/hXhPu9sGvXyi2D4vszICvc1KL4RD aLSrOsROx22eZ26KqcW4ny7+va2FnvjsZgI8h4sDmaLzKczVRIiLITiMpLFEU/VoSv0m1F4B FtRgoiyjFzigWG0MsTdAN6FJzGh4mWWGIlE7o5JraNhnTd+yTUIPtw3ym6l8P+gbvfoZida0 TspgwBWLnXQvP5EDvlZnNaKa/3oBes6z0QdaSOwZCRA3QSLHBwtgUsrT6RxRSweLrcabiEkE GBECAAkFAkah5FQCGwwACgkQ130UHQKnbvW2GgCfTKx80VvCR/PvsUlrvdOLsIgeRGAAn1ee RjMaxwtSdaCKMw3j33ZbsWS4 Message-ID: <827d2ee6-04de-f4f9-15b4-40dac90bda9c@nbd.name> Date: Sun, 3 Mar 2019 11:05:51 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190302211046.GA20268@embeddedor.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-03-02 22:10, Gustavo A. R. Silva wrote: > Hi all, > > The following piece of code in drivers/net/wireless/mediatek/mt76/mt7603/mac.c > is missing a variable assignment before line 1058. Notice that there > is a potential execution path in which variable *i* is compared against > magic number 15 at line 1075 without being initialized previously > (this was reported by Coverity): > > 1055 out: > 1056 final_rate_flags = info->status.rates[final_idx].flags; > 1057 > 1058 switch (FIELD_GET(MT_TX_RATE_MODE, final_rate)) { > 1059 case MT_PHY_TYPE_CCK: > 1060 cck = true; > 1061 /* fall through */ > 1062 case MT_PHY_TYPE_OFDM: > 1063 if (dev->mt76.chandef.chan->band == NL80211_BAND_5GHZ) > 1064 sband = &dev->mt76.sband_5g.sband; > 1065 else > 1066 sband = &dev->mt76.sband_2g.sband; > 1067 final_rate &= GENMASK(5, 0); > 1068 final_rate = mt7603_get_rate(dev, sband, final_rate, cck); > 1069 final_rate_flags = 0; > 1070 break; > 1071 case MT_PHY_TYPE_HT_GF: > 1072 case MT_PHY_TYPE_HT: > 1073 final_rate_flags |= IEEE80211_TX_RC_MCS; > 1074 final_rate &= GENMASK(5, 0); > 1075 if (i > 15) > 1076 return false; > 1077 break; > 1078 default: > 1079 return false; > 1080 } > > My guess is that such missing assignment should be something similar > to the one at line 566: > > i = FIELD_GET(MT_RXV1_TX_RATE, rxdg0); > > but I'm not sure what the proper arguments for macro FIELD_GET should > be. > > This code was introduced by commit c8846e1015022d2531ac4c895783e400b3e5babe > > What do you think? Thanks for reporting this. The fix is simpler than that, the check should be: if (final_rate > 15) I will send a fix. - Felix