From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0B3C11BDF8 for ; Wed, 11 Oct 2023 21:30:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="K7Xj88b+" Received: from mail-oo1-xc34.google.com (mail-oo1-xc34.google.com [IPv6:2607:f8b0:4864:20::c34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 63A08AF for ; Wed, 11 Oct 2023 14:30:57 -0700 (PDT) Received: by mail-oo1-xc34.google.com with SMTP id 006d021491bc7-57b5ef5b947so200023eaf.0 for ; Wed, 11 Oct 2023 14:30:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1697059856; x=1697664656; 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=gPdeSN+UCM0bKxtteCsEuwrT+LDscm/iwtDfjRU9nwc=; b=K7Xj88b+hXPMjMC0k1QJMzrw77Cb3aBXW9f6kpjs0n/F27xvEvdVDor93w/DjNFBKh UL9e6BRtL6hMkzFJMVd7qi5bZkjrHvMDfcahaq/qyUrsNTiIZDFUpvO4os3+Couej6Fm yGpnoYKDEP6n8/LpR4w3o93Nsd//CpkaaBMLc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697059856; x=1697664656; 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=gPdeSN+UCM0bKxtteCsEuwrT+LDscm/iwtDfjRU9nwc=; b=UoixCjZPydSK2g+t02TYFaxKKr73mcm2fMgq8sphLvXufG1q0L3Ye4T2dwzZXDTtSD m+/YbwbKwYbfBhux/oSyiURJkFsJCGtWbGqSMK22A1Nbp2RBpNNkRP9B1t0FX9vTQBSO s75g59xotrt2H19nX6/f4A7Z5vCCm36UrXV2ix/tLdRpnXSrbVWnExBzWWMdW+EQs5e4 xSgY+v+dlrzDdqcgdPz6w+Zu7eA7lahOzxDc5c6dXkjQ54EqEBQujOrOYxEkqiK5xFjW Bl+3Z2pBiQPMMYuzYWFZxeEiCgYrVk99UdwwmQ73bwIiBvon9HVGMu6sgCvKYlhAZycE /CiQ== X-Gm-Message-State: AOJu0Yx3/RJLJe8OzNSbM4q3zenxayE/B3gPGjvRL0Ykj25fo4m16uFC NvV9RUnctt9MuXCm+r+nPzRtsg== X-Google-Smtp-Source: AGHT+IHgiaS0J9V8G4ieZfMxkP6YJcYFtXZ8HWNnNVZcyH53BKixjx9bhz+wn0W15U33LD4O25xHlw== X-Received: by 2002:a05:6358:528d:b0:134:c279:c829 with SMTP id g13-20020a056358528d00b00134c279c829mr30279195rwa.18.1697059855858; Wed, 11 Oct 2023 14:30:55 -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 g9-20020a639f09000000b00565dd935938sm309145pge.85.2023.10.11.14.30.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Oct 2023 14:30:55 -0700 (PDT) Date: Wed, 11 Oct 2023 14:30:54 -0700 From: Kees Cook To: Justin Stitt Cc: Tariq Toukan , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] net/mlx4_core: replace deprecated strncpy with strscpy Message-ID: <202310111430.C419092@keescook> References: <20231011-strncpy-drivers-net-ethernet-mellanox-mlx4-fw-c-v1-1-4d7b5d34c933@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231011-strncpy-drivers-net-ethernet-mellanox-mlx4-fw-c-v1-1-4d7b5d34c933@google.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Wed, Oct 11, 2023 at 09:04:37PM +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 `dst` to be NUL-terminated based on its use with format > strings: > | mlx4_dbg(dev, "Reporting Driver Version to FW: %s\n", dst); > > Moreover, NUL-padding is not required. Yup, since it's only use is for the above report. > > 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 Thanks! Reviewed-by: Kees Cook -- Kees Cook