From: Kees Cook <keescook@chromium.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Vishal Verma <vishal.l.verma@intel.com>,
Dave Jiang <dave.jiang@intel.com>,
nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] dax: refactor deprecated strncpy
Date: Thu, 14 Sep 2023 20:40:51 -0700 [thread overview]
Message-ID: <202309142040.7FCE9E230A@keescook> (raw)
In-Reply-To: <20230913-strncpy-drivers-dax-bus-c-v1-1-bee91f20825b@google.com>
On Wed, Sep 13, 2023 at 01:10:24AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
>
> We should prefer more robust and less ambiguous string interfaces.
>
> `dax_id->dev_name` is expected to be NUL-terminated and has been zero-allocated.
>
> A suitable replacement is `strscpy` [2] due to the fact that it
> guarantees NUL-termination on the destination buffer. Moreover, due to
> `dax_id` being zero-allocated the padding behavior of `strncpy` is not
> needed and a simple 1:1 replacement of strncpy -> strscpy should
> suffice.
>
> 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 <justinstitt@google.com>
Looks correct to me.
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
prev parent reply other threads:[~2023-09-15 3:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 1:10 [PATCH] dax: refactor deprecated strncpy Justin Stitt
2023-09-13 15:35 ` Dave Jiang
2023-09-15 3:40 ` Kees Cook [this message]
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