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=-14.4 required=3.0 tests=DKIMWL_WL_MED,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_IN_DEF_DKIM_WL autolearn=unavailable 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 283C7C433E0 for ; Thu, 4 Jun 2020 20:16:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 045202067B for ; Thu, 4 Jun 2020 20:16:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Ul9IqQ41" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729842AbgFDUQ2 (ORCPT ); Thu, 4 Jun 2020 16:16:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728836AbgFDUQV (ORCPT ); Thu, 4 Jun 2020 16:16:21 -0400 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA172C08C5C0 for ; Thu, 4 Jun 2020 13:16:20 -0700 (PDT) Received: by mail-pf1-x442.google.com with SMTP id b5so3772607pfp.9 for ; Thu, 04 Jun 2020 13:16:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pCXmYsl76J0CAlxoPdk8mPZO/WOJwZ5J1IK/xTYSvtY=; b=Ul9IqQ41ZiXh1TA37NXxQoP1MYWZkk1ImeHfZoGz6a6IPTQKCTgkI4vMbYvxIt8wpE ElHA9RWwTvFCaySEtclTRP/dyePJtOWdEk29ahiOH2gLk0aIx7jxMqS8sHpI0dAD9/eD v2pQeh6hmu6BRKkCyhh5mYDGk/czBtEllytZVgQeNFhavoEfrbFwLLVfzZ/2XW9eqAuC T6PPxSNZdkIUyyCpj3L+bHh3A58HE+YTCCyomOaAjuPFYAu7WNLA0VPJGgc8Oy3KvimW enSRBgfNysV+6XPIzSx1E3hPpfiQZPkCEErtaeB8Ewgc+PLJOHksAeBzo6J1PIYEAlTL B91g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=pCXmYsl76J0CAlxoPdk8mPZO/WOJwZ5J1IK/xTYSvtY=; b=PW+OKqgBIv413u6/PM/M+cvKICrtq9/rsiRoTJFGDrlCShExS8dRrjjOMFw40JbxcB vDiZthpGGUF2DSo0TAbejPXmSN4ZbKN9lty8D9VFC0HP+JnM5xhyns//uyQD+5qTWCJ2 iCqTcUZbakwX9TdubYJh188E797XDbGkPa0I+nmeUsWHfnphTWRaGpJwT2ihBADctBpm xWuhocBPNmz9ACUSPC5hHBOPGaG+gCu2ClJRhvH2SaWiCTgdzTh2IT8kWrRz2b5Do+YV hk2gmXdLEwKTOL96viRVUAM0verIov6v3me7543UeJ9nYWUi5Dyup5P38kIMKVe45Fk5 WN1g== X-Gm-Message-State: AOAM532bXt25LiHiqUN5ZR7OFQReGgwcPfzfyW51Oc5lGX8drqjxTgI7 TMcXLNQCmzZXdWxVPWaauzN1BRgbAOiYztmckZ3GCgU9wMM= X-Google-Smtp-Source: ABdhPJye6FZH70P5vXHcitY46EI4rxFnZqJif4KZJI8zWDppq3cq3MmDJfiH17IwjHHvUarffuS8hk7FOMV62ymzGuM= X-Received: by 2002:a63:4f09:: with SMTP id d9mr5970154pgb.10.1591301780211; Thu, 04 Jun 2020 13:16:20 -0700 (PDT) MIME-Version: 1.0 References: <20200603233203.1695403-1-keescook@chromium.org> <20200603233203.1695403-5-keescook@chromium.org> In-Reply-To: <20200603233203.1695403-5-keescook@chromium.org> From: Nick Desaulniers Date: Thu, 4 Jun 2020 13:16:08 -0700 Message-ID: Subject: Re: [PATCH 04/10] rtlwifi: rtl8192cu: Remove uninitialized_var() usage To: Kees Cook Cc: LKML , Linus Torvalds , Miguel Ojeda , Alexander Potapenko , Joe Perches , Andy Whitcroft , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, Network Development , linux-wireless , linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, Linux Memory Management List , clang-built-linux Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 3, 2020 at 4:32 PM Kees Cook wrote: > > Using uninitialized_var() is dangerous as it papers over real bugs[1] > (or can in the future), and suppresses unrelated compiler warnings (e.g. > "unused variable"). If the compiler thinks it is uninitialized, either > simply initialize the variable or make compiler changes. As a precursor > to removing[2] this[3] macro[4], just initialize this variable to NULL, > and avoid sending garbage by returning. > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ > > Signed-off-by: Kees Cook Reviewed-by: Nick Desaulniers Fixes: dc0313f46664 ("rtlwifi: rtl8192cu: Add routine hw") > --- > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > index f070f25bb735..5b071b70bc08 100644 > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > @@ -592,7 +592,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, > bool wmm_enable, > u8 queue_sel) > { > - u16 uninitialized_var(value); > + u16 value; > > switch (queue_sel) { > case TX_SELE_HQ: > @@ -606,7 +606,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, > break; > default: > WARN_ON(1); /* Shall not reach here! */ > - break; > + return; > } > _rtl92c_init_chipn_reg_priority(hw, value, value, value, value, > value, value); Whew! Nothing like passing the same value 6 times! (Other callers do use distinct values though, just curious seeing this instance.) -- Thanks, ~Nick Desaulniers