[PATCH net-next] net/sched: replace strncpy with strscpy

[PATCH net-next] net/sched: replace strncpy with strscpy

[Pranav Tyagi]

Replace the deprecated strncpy() with strscpy() as the destination
buffer should be NUL-terminated and does not require any trailing
NUL-padding. Also, since NUL-termination is guaranteed,
use sizeof(conf.algo) in place of sizeof(conf.algo) - 1
as the size parameter.

Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
---
 net/sched/em_text.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/em_text.c b/net/sched/em_text.c
index 420c66203b17..1d0debfd62e5 100644
--- a/net/sched/em_text.c
+++ b/net/sched/em_text.c
@@ -108,7 +108,7 @@ static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
 	struct text_match *tm = EM_TEXT_PRIV(m);
 	struct tcf_em_text conf;
 
-	strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
+	strscpy(conf.algo, tm->config->ops->name, sizeof(conf.algo));
 	conf.from_offset = tm->from_offset;
 	conf.to_offset = tm->to_offset;
 	conf.from_layer = tm->from_layer;
-- 
2.49.0

Re: [PATCH net-next] net/sched: replace strncpy with strscpy

[Simon Horman]

On Tue, Jun 17, 2025 at 06:05:31PM +0530, Pranav Tyagi wrote:
> Replace the deprecated strncpy() with strscpy() as the destination
> buffer should be NUL-terminated and does not require any trailing
> NUL-padding. Also, since NUL-termination is guaranteed,
> use sizeof(conf.algo) in place of sizeof(conf.algo) - 1
> as the size parameter.
> 
> Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> ---
>  net/sched/em_text.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/sched/em_text.c b/net/sched/em_text.c
> index 420c66203b17..1d0debfd62e5 100644
> --- a/net/sched/em_text.c
> +++ b/net/sched/em_text.c
> @@ -108,7 +108,7 @@ static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
>  	struct text_match *tm = EM_TEXT_PRIV(m);
>  	struct tcf_em_text conf;
>  
> -	strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
> +	strscpy(conf.algo, tm->config->ops->name, sizeof(conf.algo));

Hi Pranav,

Because the destination is an array I think we can use the two-argument
version of strscpy() here.

	strscpy(conf.algo, tm->config->ops->name);

>  	conf.from_offset = tm->from_offset;
>  	conf.to_offset = tm->to_offset;
>  	conf.from_layer = tm->from_layer;

-- 
pw-bot: changes-requested

Re: [PATCH net-next] net/sched: replace strncpy with strscpy

[Pranav Tyagi]

On Wed, Jun 18, 2025 at 4:24 PM Simon Horman <horms@kernel.org> wrote:
>
> On Tue, Jun 17, 2025 at 06:05:31PM +0530, Pranav Tyagi wrote:
> > Replace the deprecated strncpy() with strscpy() as the destination
> > buffer should be NUL-terminated and does not require any trailing
> > NUL-padding. Also, since NUL-termination is guaranteed,
> > use sizeof(conf.algo) in place of sizeof(conf.algo) - 1
> > as the size parameter.
> >
> > Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> > ---
> >  net/sched/em_text.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/sched/em_text.c b/net/sched/em_text.c
> > index 420c66203b17..1d0debfd62e5 100644
> > --- a/net/sched/em_text.c
> > +++ b/net/sched/em_text.c
> > @@ -108,7 +108,7 @@ static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
> >       struct text_match *tm = EM_TEXT_PRIV(m);
> >       struct tcf_em_text conf;
> >
> > -     strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
> > +     strscpy(conf.algo, tm->config->ops->name, sizeof(conf.algo));
>
> Hi Pranav,
>
> Because the destination is an array I think we can use the two-argument
> version of strscpy() here.
>
>         strscpy(conf.algo, tm->config->ops->name);
>
> >       conf.from_offset = tm->from_offset;
> >       conf.to_offset = tm->to_offset;
> >       conf.from_layer = tm->from_layer;
>
> --
> pw-bot: changes-requested

Hi,

Thanks for the feedback. I'll update the patch accordingly
and send a v2 for the same.

Regards
Pranav Tyagi