linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Kees Cook <keescook@chromium.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Andi Shyti <andi.shyti@kernel.org>,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
	Nicholas Piggin <npiggin@gmail.com>,
	linuxppc-dev@lists.ozlabs.org, linux-i2c@vger.kernel.org
Subject: Re: [PATCH] i2c: replace deprecated strncpy
Date: Wed, 20 Sep 2023 07:33:11 -0700	[thread overview]
Message-ID: <202309200732.29C44010F6@keescook> (raw)
In-Reply-To: <20230920-strncpy-drivers-i2c-busses-i2c-powermac-c-v1-1-0a3e9a107f8a@google.com>

On Wed, Sep 20, 2023 at 11:07:35AM +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.
> 
> `info.type` is expected to be NUL-terminated judging by its use in
> `i2c_new_client_device()` wherein it is used to populate `client->name`:
> |	strscpy(client->name, info->type, sizeof(client->name));
> 
> NUL-padding is not required and even if it was, `client` is already
> zero-initialized.
> 
> Considering the two points from 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
> Signed-off-by: Justin Stitt <justinstitt@google.com>

Looks like a straight replacement. Thanks!

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

-- 
Kees Cook

  reply	other threads:[~2023-09-20 14:34 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-09-20 11:07 [PATCH] i2c: replace deprecated strncpy Justin Stitt
2023-09-20 14:33 ` Kees Cook [this message]
2023-09-22 10:12 ` Wolfram Sang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=202309200732.29C44010F6@keescook \
    --to=keescook@chromium.org \
    --cc=andi.shyti@kernel.org \
    --cc=justinstitt@google.com \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=npiggin@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).