Re: [PATCH] ionic: replace deprecated strncpy with strscpy

Justin Stitt
2023-10-11T22:25:47Z

On Wed, Oct 11, 2023 at 3:17 PM Nelson, Shannon <shannon.nelson@amd.com> wrote:
>
> On 10/11/2023 2:53 PM, 'Justin Stitt' via Pensando Drivers wrote:
> >
> > strncpy() is deprecated for use on NUL-terminated destination strings
> > [1] and as such we should prefer more robust and less ambiguous string
> > interfaces.
> >
> > NUL-padding is not needed due to `ident` being memset'd to 0 just before
> > the copy.
> >
> > Considering the 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>
>
> Thanks, I suspected this was coming soon :-)
>
> Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>

Thanks Shannon!

>
>
> > ---
> > Note: build-tested only.
> >
> > Found with: $ rg "strncpy\("
> > ---
> > drivers/net/ethernet/pensando/ionic/ionic_main.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_main.c b/drivers/net/ethernet/pensando/ionic/ionic_main.c
> > index 1dc79cecc5cc..835577392178 100644
> > --- a/drivers/net/ethernet/pensando/ionic/ionic_main.c
> > +++ b/drivers/net/ethernet/pensando/ionic/ionic_main.c
> > @@ -554,8 +554,8 @@ int ionic_identify(struct ionic *ionic)
> > memset(ident, 0, sizeof(*ident));
> >
> > ident->drv.os_type = cpu_to_le32(IONIC_OS_TYPE_LINUX);
> > - strncpy(ident->drv.driver_ver_str, UTS_RELEASE,
> > - sizeof(ident->drv.driver_ver_str) - 1);
> > + strscpy(ident->drv.driver_ver_str, UTS_RELEASE,
> > + sizeof(ident->drv.driver_ver_str));
> >
> > mutex_lock(&ionic->dev_cmd_lock);
> >
> >
> > ---
> > base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
> > change-id: 20231011-strncpy-drivers-net-ethernet-pensando-ionic-ionic_main-c-709f8f1ea312
> >
> > Best regards,
> > --
> > Justin Stitt <justinstitt@google.com>
> >