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
next prev parent 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
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