From: Kees Cook <keescook@chromium.org>
To: Justin Stitt <justinstitt@google.com>
Cc: Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: Re: [PATCH] HID: prodikeys: refactor deprecated strncpy
Date: Thu, 14 Sep 2023 22:02:12 -0700 [thread overview]
Message-ID: <202309142201.683ED5A7FD@keescook> (raw)
In-Reply-To: <20230914-strncpy-drivers-hid-hid-prodikeys-c-v1-1-10c00550f2c2@google.com>
On Thu, Sep 14, 2023 at 10:20:55PM +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.
>
> 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>
> ---
> Note: for some reason if NUL-padding is needed let's opt for `strscpy_pad()`
> ---
> drivers/hid/hid-prodikeys.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hid/hid-prodikeys.c b/drivers/hid/hid-prodikeys.c
> index e4e9471d0f1e..c16d2ba6ea16 100644
> --- a/drivers/hid/hid-prodikeys.c
> +++ b/drivers/hid/hid-prodikeys.c
> @@ -639,9 +639,9 @@ static int pcmidi_snd_initialise(struct pcmidi_snd *pm)
> goto fail;
> }
>
> - strncpy(card->driver, shortname, sizeof(card->driver));
> - strncpy(card->shortname, shortname, sizeof(card->shortname));
> - strncpy(card->longname, longname, sizeof(card->longname));
> + strscpy(card->driver, shortname, sizeof(card->driver));
> + strscpy(card->shortname, shortname, sizeof(card->shortname));
> + strscpy(card->longname, longname, sizeof(card->longname));
"card" is already kzalloc()ed so no _pad() is needed, good.
>
> /* Set up rawmidi */
> err = snd_rawmidi_new(card, card->shortname, 0,
> @@ -652,7 +652,7 @@ static int pcmidi_snd_initialise(struct pcmidi_snd *pm)
> goto fail;
> }
> pm->rwmidi = rwmidi;
> - strncpy(rwmidi->name, card->shortname, sizeof(rwmidi->name));
> + strscpy(rwmidi->name, card->shortname, sizeof(rwmidi->name));
> rwmidi->info_flags = SNDRV_RAWMIDI_INFO_INPUT;
> rwmidi->private_data = pm;
Same here.
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
>
>
> ---
> base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec
> change-id: 20230914-strncpy-drivers-hid-hid-prodikeys-c-cf42614a21d4
>
> Best regards,
> --
> Justin Stitt <justinstitt@google.com>
>
--
Kees Cook
next prev parent reply other threads:[~2023-09-15 5:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-14 22:20 [PATCH] HID: prodikeys: refactor deprecated strncpy Justin Stitt
2023-09-15 5:02 ` Kees Cook [this message]
2023-09-29 18:47 ` Kees Cook
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