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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18C6ECD98C0 for ; Tue, 10 Oct 2023 23:59:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344255AbjJJX7Q (ORCPT ); Tue, 10 Oct 2023 19:59:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33798 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344207AbjJJX7P (ORCPT ); Tue, 10 Oct 2023 19:59:15 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD32F91 for ; Tue, 10 Oct 2023 16:59:13 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id d9443c01a7336-1c5cd27b1acso49752995ad.2 for ; Tue, 10 Oct 2023 16:59:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1696982353; x=1697587153; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=VqSRijF5ocWf9llqvklQyW3Wi+0XOkmzW4XQNxfluyk=; b=XR6IMS+gkfiwKqtsxSJF4Vcm0HKo0Y6oo38lcIgD6XeQqt7Yj559bQOm9TZEFE5Bg1 AkhxZYp2t44sJL9y0/NvxPko2qIXPffLLjRSA77ELSzQ4ZyWnRlf+7fXTqr398ieZ9PA vBqvf3Knf6mPaYByYrP3BkGXk0KJavVmQ6Q+U= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696982353; x=1697587153; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=VqSRijF5ocWf9llqvklQyW3Wi+0XOkmzW4XQNxfluyk=; b=dg8bFz9CFzh7xbrE022MeEVFgnt2U5USW5pDlLWQivYuYJNPo7T4WygVOz1bNZvfAh lWs1eL4Gi7n3avF0vRf6k/1IFgVDaQwe/OcoxYpo2SJeJWZ48pCnAK0FguUr/riyl8yf bygT4KRQP9lyv7D1Te6317WY00jjWp2BBcuY7x4Cg1a5rqxWndymW6PrGqzdkkp55G9D 3OQvPr2wK7Rt/3zwRHGXRV2x1fimhI4fuJkEijlvMJe3mikq3VpOv37IT14KmlzMn30i c6HlP1Jc4eFGLKZSzDcSCTa93FcbUWp9/+l0QKndVlQ7FGHjWd5qmIXGeaZ8HlHlQh7w 70UA== X-Gm-Message-State: AOJu0Yz0g1Yf16/otX+QuUDMEyzpqiv+KpHE8VwwyoIGEweyjW0jJtmF vEVb2d6D+Clag44wK/J71DjP+A== X-Google-Smtp-Source: AGHT+IHsBKEhM8Jb2S10+0UBKcAaUvwNQ94/ERbNOjqhOH8T4jx/rmPG2GZ2PApSYSOqP4sqNCXXdg== X-Received: by 2002:a17:902:7d92:b0:1c6:943:baca with SMTP id a18-20020a1709027d9200b001c60943bacamr19039967plm.28.1696982353259; Tue, 10 Oct 2023 16:59:13 -0700 (PDT) Received: from www.outflux.net (198-0-35-241-static.hfc.comcastbusiness.net. [198.0.35.241]) by smtp.gmail.com with ESMTPSA id ij15-20020a170902ab4f00b001c9c47d6cb9sm940689plb.99.2023.10.10.16.59.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Oct 2023 16:59:12 -0700 (PDT) Date: Tue, 10 Oct 2023 16:59:10 -0700 From: Kees Cook To: Justin Stitt Cc: Marcin Wojtas , Russell King , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] net: mvpp2: replace deprecated strncpy with strscpy Message-ID: <202310101658.8D498F16F@keescook> References: <20231010-strncpy-drivers-net-ethernet-marvell-mvpp2-mvpp2_main-c-v1-1-51be96ad0324@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231010-strncpy-drivers-net-ethernet-marvell-mvpp2-mvpp2_main-c-v1-1-51be96ad0324@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 10, 2023 at 09:24:42PM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > We expect `irqname` to be NUL-terminated based on its use with > of_irq_get_byname() -> of_property_match_string() wherein it is used > with a format string and a `strcmp`: > | pr_debug("comparing %s with %s\n", string, p); > | if (strcmp(string, p) == 0) > | return i; /* Found it; return index */ > > NUL-padding is not required as is evident by other assignments to > `irqname` which do not NUL-pad: > | if (port->flags & MVPP2_F_DT_COMPAT) > | snprintf(irqname, sizeof(irqname), "tx-cpu%d", i); > | else > | snprintf(irqname, sizeof(irqname), "hif%d", i); > > Considering the above, a suitable replacement is `strscpy` [2] due to > the fact that it guarantees NUL-termination on the destination buffer > without unnecessarily NUL-padding. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt Yup, direct replacement. Reviewed-by: Kees Cook -- Kees Cook