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Date:   Wed, 20 Sep 2023 08:36:51 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Justin Sanders <justin@coraid.com>, Jens Axboe <axboe@kernel.dk>,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org, Xu Panda <xu.panda@zte.com.cn>,
        Yang Yang <yang.yang29@zte.com>
Subject: Re: [PATCH v2] aoe: replace strncpy with strscpy
Message-ID: <202309200836.372F9757@keescook>
References: <20230919-strncpy-drivers-block-aoe-aoenet-c-v2-1-3d5d158410e9@google.com>
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In-Reply-To: <20230919-strncpy-drivers-block-aoe-aoenet-c-v2-1-3d5d158410e9@google.com>
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On Tue, Sep 19, 2023 at 05:27:45AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> `aoe_iflist` is expected to be NUL-terminated which is evident by its
> use with string apis later on like `strspn`:
> | 	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
> 
> It also seems `aoe_iflist` does not need to be NUL-padded which means
> `strscpy` [2] is a suitable replacement due to the fact that it
> guarantees NUL-termination on the destination buffer while not
> 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
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Xu Panda <xu.panda@zte.com.cn>
> Cc: Yang Yang <yang.yang29@zte.com>
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Looks right. Thanks!

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook