Re: [PATCH 01/11] staging: vc04_services: changen strncpy() to strscpy_pad()

Justin Stitt
2024-03-28T23:10:50Z

Hi,

On Thu, Mar 28, 2024 at 03:04:45PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> gcc-14 warns about this strncpy() that results in a non-terminated
> string for an overflow:
>
> In file included from include/linux/string.h:369,
> from drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:20:
> In function 'strncpy',
> inlined from 'create_component' at drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:940:2:
> include/linux/fortify-string.h:108:33: error: '__builtin_strncpy' specified bound 128 equals destination size [-Werror=stringop-truncation]
>
> Change it to strscpy_pad(), which produces a properly terminated and
> zero-padded string.
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

If there is other review that warrants a change, we might as well switch
over to the new 2-argument version of strscpy{_pad}() introduced in
Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). No need to
change for only this reason, though.

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
> drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> index 258aa0e37f55..6ca5797aeae5 100644
> --- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> +++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> @@ -937,8 +937,8 @@ static int create_component(struct vchiq_mmal_instance *instance,
> /* build component create message */
> m.h.type = MMAL_MSG_TYPE_COMPONENT_CREATE;
> m.u.component_create.client_component = component->client_component;
> - strncpy(m.u.component_create.name, name,
> - sizeof(m.u.component_create.name));
> + strscpy_pad(m.u.component_create.name, name,
> + sizeof(m.u.component_create.name));
>
> ret = send_synchronous_mmal_msg(instance, &m,
> sizeof(m.u.component_create),
> --
> 2.39.2
>

Thanks
Justin