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 0CFFBCDB474 for ; Mon, 16 Oct 2023 18:15:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231611AbjJPSOr (ORCPT ); Mon, 16 Oct 2023 14:14:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229943AbjJPSOp (ORCPT ); Mon, 16 Oct 2023 14:14:45 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1190AE6 for ; Mon, 16 Oct 2023 11:14:43 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id 4fb4d7f45d1cf-53ed4688b9fso2021571a12.0 for ; Mon, 16 Oct 2023 11:14:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1697480081; x=1698084881; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=qRL/6VX7HAEyDPGl2HTyivOlN20wjAMOil4U+8Zf2+k=; b=AhLgjgLZl67P4j/YjKLQIhP8byxtkC3GAroqeIuYOLU+9dshhBBbkZl8/eo9bwt4/D 7LJatgprrWqA5mH8Vwwnv1AbWv/hCau2SiSIuhlOQVhvzGEBbJLH4l8UHA/xd0SvkSR1 OAEx6jFJMi5ZrPkjksqbk8xykprcoqxDSCGqBIsmxowFQsiWlzCkCfjeeAb04C6+9Xp6 84fGRXnGmdQCFLNU3Myp6QmQpg47lWwzvQEAp31tlL+Qbh90Ia95HZ9dAbOT6yMTSqYy WhVn5GQV3A8y9Hi451da10evusKZ2BY3HHSP3Dn4mgdEJ28kJCllEIHN6xcAuRxu3D+A +Y9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697480081; x=1698084881; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qRL/6VX7HAEyDPGl2HTyivOlN20wjAMOil4U+8Zf2+k=; b=krCCrtnG7l9GB8PFxoiclsgMOx/ua1HQkpPskanbw/vazSS5FvaetizwHsHC8vKE2g ssfWQE3WakKS1Zrd9x93KOfI1NnQmafigxTbTwOLZZbrFcP0UBnobFFtayME+2ycQgxk 74YPghXdyR/ha3al9i3Pf21a3zdenBfiacCIYJX/BgXMiMx6WNALus44hCVMqiQH43Ci ObjKDugq0faC7cQW2uCTbG/6+lu0AaD5YYK24E7ceh7Y610fsCgLWlWcdMIqqP9FMtmF JOmOiqkrXH1zHvi2fRdEjDD3ln0FDmH6zWZx3AkzXElQcxshJze7R9YDffBTO0KRuCsH s/UQ== X-Gm-Message-State: AOJu0YzJkLko02WKYRRXj1vBP7WmcFIXVEcg8cGEFgJNVQ0lskxYZ/Vm 52lv70xVNkKJ2pjPAq+CMb2xXe1A6E3U1gzdA33jTA== X-Google-Smtp-Source: AGHT+IHWE+5Rhq2pCOMoR8bDSaQb/FjDy2AMJAB/4FZZkaJ3R2ZA5dlO1ZAXGzdrzGkzocSaigLv2m8YWy8QwPOXlIA= X-Received: by 2002:aa7:d1c7:0:b0:53e:1815:ed0f with SMTP id g7-20020aa7d1c7000000b0053e1815ed0fmr8825edp.31.1697480081468; Mon, 16 Oct 2023 11:14:41 -0700 (PDT) MIME-Version: 1.0 References: <20231012-strncpy-drivers-net-ethernet-qlogic-qlcnic-qlcnic_83xx_init-c-v1-1-f0008d5e43be@google.com> <202310141944.08A1FF6D9@keescook> In-Reply-To: <202310141944.08A1FF6D9@keescook> From: Justin Stitt Date: Mon, 16 Oct 2023 11:14:29 -0700 Message-ID: Subject: Re: [PATCH] qlcnic: replace deprecated strncpy with strscpy To: Kees Cook Cc: Shahed Shaikh , Manish Chopra , GR-Linux-NIC-Dev@marvell.com, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 14, 2023 at 7:47=E2=80=AFPM Kees Cook w= rote: > > On Thu, Oct 12, 2023 at 07:44:29PM +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 fw_info->fw_file_name to be NUL-terminated based on its use > > within _request_firmware_prepare() wherein `name` refers to it: > > | if (firmware_request_builtin_buf(firmware, name, dbuf, size)) { > > | dev_dbg(device, "using built-in %s\n", name); > > | return 0; /* assigned */ > > | } > > ... and with firmware_request_builtin() also via `name`: > > | if (strcmp(name, b_fw->name) =3D=3D 0) { > > > > There is no evidence that NUL-padding is required. > > > > 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. > > When doing the hard-coded value to sizeof(), can you include in the > commit log the rationale for it? For example: > > Additionally replace size macro (QLC_FW_FILE_NAME_LEN) with > sizeof(fw_info->fw_file_name) to more directly tie the maximum buffer > size to the destination buffer: > > struct qlc_83xx_fw_info { > ... > char fw_file_name[QLC_FW_FILE_NAME_LEN]; > }; > Sure, I'll be doing this from now on to make the change more clear! > > > > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#st= rncpy-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 > > --- > > Note: build-tested only. > > > > Found with: $ rg "strncpy\(" > > --- > > drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 12 ++++++-----= - > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/dr= ivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c > > index c95d56e56c59..b733374b4dc5 100644 > > --- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c > > +++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c > > @@ -2092,8 +2092,8 @@ static int qlcnic_83xx_run_post(struct qlcnic_ada= pter *adapter) > > return -EINVAL; > > } > > > > - strncpy(fw_info->fw_file_name, QLC_83XX_POST_FW_FILE_NAME, > > - QLC_FW_FILE_NAME_LEN); > > + strscpy(fw_info->fw_file_name, QLC_83XX_POST_FW_FILE_NAME, > > + sizeof(fw_info->fw_file_name)); > > > > ret =3D request_firmware(&fw_info->fw, fw_info->fw_file_name, dev= ); > > if (ret) { > > @@ -2396,12 +2396,12 @@ static int qlcnic_83xx_get_fw_info(struct qlcni= c_adapter *adapter) > > switch (pdev->device) { > > case PCI_DEVICE_ID_QLOGIC_QLE834X: > > case PCI_DEVICE_ID_QLOGIC_QLE8830: > > - strncpy(fw_info->fw_file_name, QLC_83XX_FW_FILE_N= AME, > > - QLC_FW_FILE_NAME_LEN); > > + strscpy(fw_info->fw_file_name, QLC_83XX_FW_FILE_N= AME, > > + sizeof(fw_info->fw_file_name)); > > break; > > case PCI_DEVICE_ID_QLOGIC_QLE844X: > > - strncpy(fw_info->fw_file_name, QLC_84XX_FW_FILE_N= AME, > > - QLC_FW_FILE_NAME_LEN); > > + strscpy(fw_info->fw_file_name, QLC_84XX_FW_FILE_N= AME, > > + sizeof(fw_info->fw_file_name)); > > break; > > default: > > dev_err(&pdev->dev, "%s: Invalid device id\n", > > But yes, this all looks right to me. > > Reviewed-by: Kees Cook > > -- > Kees Cook Thanks Justin