From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 248AA20B29 for ; Mon, 23 Oct 2023 17:29:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FR4CDg9m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BCFEC433C8; Mon, 23 Oct 2023 17:29:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1698082173; bh=TFyddzODnA71wlttcWczDl2ULr/aiDXiJcRsmEttaXE=; h=Subject:From:In-Reply-To:References:To:Cc:Date:From; b=FR4CDg9m+SAmdKCzpr0yZ9kRTMHdtjdTtTLzAcWdAH2yo8eedoUNIFEorpJTshynG +YIHrRJaVeB96pyOq7vW2AX/P/YINun0pPUCFpCCio2CmrzoPavpNxejtI70mgOJ/5 vVFQGjBFuDNHix5xbmPTuwhcJ5KoMpeX40B4+FlKw/nvvY+i2I6+rZyuWuMWPUi3pf 5GXWapp8Py6yGmz/5vSyzP5pBPr0jVD8vtoT9tMu3OtsIqDm927tLF0BaKBi82fKDc c+IlEQDp6L/d55EOUO6VSwaas0pX/MYgeRVpkLcDJrjhH+MuHvT6gEKZRbmDORnX3O DtF8zDpM4/ZXQ== Content-Type: text/plain; charset="utf-8" Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: wifi: wlcore: boot: replace deprecated strncpy with strscpy From: Kalle Valo In-Reply-To: <20231018-strncpy-drivers-net-wireless-ti-wlcore-boot-c-v1-1-d3c6cc6b80fe@google.com> References: <20231018-strncpy-drivers-net-wireless-ti-wlcore-boot-c-v1-1-d3c6cc6b80fe@google.com> To: Justin Stitt Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Justin Stitt User-Agent: pwcli/0.1.1-git (https://github.com/kvalo/pwcli/) Python/3.11.2 Message-ID: <169808217070.695306.9829944196418700359.kvalo@kernel.org> Date: Mon, 23 Oct 2023 17:29:32 +0000 (UTC) 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 wl->chip.fw_ver_str to be NUL-terminated based on its usage > with DRIVER_STATE_PRINT_STR() in debugfs.c: > 491 | DRIVER_STATE_PRINT_STR(chip.fw_ver_str); > ... which uses DRIVER_STATE_PRINT(): > 444 | #define DRIVER_STATE_PRINT_STR(x) DRIVER_STATE_PRINT(x, "%s") > ... which relies on scnprintf: > 434 | #define DRIVER_STATE_PRINT(x, fmt) \ > 435 | (res += scnprintf(buf + res, DRIVER_STATE_BUF_LEN - res,\ > 436 | #x " = " fmt "\n", wl->x)) > > Moreover, NUL-padding is not 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. > > 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 > Similar-to: https://lore.kernel.org/all/20231018-strncpy-drivers-net-wireless-ti-wl18xx-main-c-v2-1-ab828a491ce5@google.com/ > Signed-off-by: Justin Stitt > Reviewed-by: Kees Cook Patch applied to wireless-next.git, thanks. 75fdaa28f103 wifi: wlcore: boot: replace deprecated strncpy with strscpy -- https://patchwork.kernel.org/project/linux-wireless/patch/20231018-strncpy-drivers-net-wireless-ti-wlcore-boot-c-v1-1-d3c6cc6b80fe@google.com/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches