Messages in this thread Patch in this message | | | Date | Thu, 14 Sep 2023 20:18:44 -0700 | From | Kees Cook <> | Subject | Re: [PATCH] auxdisplay: panel: refactor deprecated strncpy |
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On Mon, Sep 11, 2023 at 08:51:04PM +0000, Justin Stitt wrote: > `strncpy` is deprecated and as such we should prefer more robust and > less ambiguous interfaces. > > In this case, all of `press_str`, `repeat_str` and `release_str` are > explicitly marked as nonstring: > | struct { /* valid when type == INPUT_TYPE_KBD */ > | char press_str[sizeof(void *) + sizeof(int)] __nonstring; > | char repeat_str[sizeof(void *) + sizeof(int)] __nonstring; > | char release_str[sizeof(void *) + sizeof(int)] __nonstring; > | } kbd; > > ... which makes `strtomem_pad` a suitable replacement as it is > functionally the same whilst being more obvious about its behavior.
Yup, this is exactly what strtomem_pad() was made for. :)
Reviewed-by: Kees Cook <keescook@chromium.org>
-Kees
> > 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 > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> > --- > Note: build-tested > --- > drivers/auxdisplay/panel.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/auxdisplay/panel.c b/drivers/auxdisplay/panel.c > index eba04c0de7eb..e20d35bdf5fe 100644 > --- a/drivers/auxdisplay/panel.c > +++ b/drivers/auxdisplay/panel.c > @@ -1449,10 +1449,9 @@ static struct logical_input *panel_bind_key(const char *name, const char *press, > key->rise_time = 1; > key->fall_time = 1; > > - strncpy(key->u.kbd.press_str, press, sizeof(key->u.kbd.press_str)); > - strncpy(key->u.kbd.repeat_str, repeat, sizeof(key->u.kbd.repeat_str)); > - strncpy(key->u.kbd.release_str, release, > - sizeof(key->u.kbd.release_str)); > + strtomem_pad(key->u.kbd.press_str, press, '\0'); > + strtomem_pad(key->u.kbd.repeat_str, repeat, '\0'); > + strtomem_pad(key->u.kbd.release_str, release, '\0'); > list_add(&key->list, &logical_inputs); > return key; > } > > --- > base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c > change-id: 20230911-strncpy-drivers-auxdisplay-panel-c-83bce51f32cb > > Best regards, > -- > Justin Stitt <justinstitt@google.com> >
-- Kees Cook
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