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Date:   Sat, 23 Sep 2023 19:51:58 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Borislav Petkov <bp@alien8.de>, Tony Luck <tony.luck@intel.com>,
        James Morse <james.morse@arm.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Robert Richter <rric@kernel.org>, linux-edac@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH v4] EDAC/mc_sysfs: refactor deprecated strncpy
Message-ID: <202309231950.698026E687@keescook>
References: <20230918-strncpy-drivers-edac-edac_mc_sysfs-c-v4-1-38a23d2fcdd8@google.com>
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In-Reply-To: <20230918-strncpy-drivers-edac-edac_mc_sysfs-c-v4-1-38a23d2fcdd8@google.com>
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On Mon, Sep 18, 2023 at 07:47:29AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
> 
> We've already calculated bounds, possible truncation with '\0' or '\n'
> and manually NUL-terminated. The situation is now just a literal byte
> copy from one buffer to another, let's treat it as such and use a less
> ambiguous interface in memcpy.
> 
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: linux-hardening@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Yeah, I think this looks good now. If a v5 is needed, a tiny improvement
would be to update the Subject: to "...: replace strncpy with memcpy".

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

-Kees

-- 
Kees Cook