Re: [PATCH] net/smc: replace strncpy with strscpy

Pranav Tyagi
2025-06-18T14:32:40Z

On Wed, Jun 18, 2025 at 4:20 PM Simon Horman <horms@kernel.org> wrote:
>
> On Tue, Jun 17, 2025 at 05:55:12PM +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.
> >
> > Signed-off-by: Pranav Tyagi <pranav.tyagi03@gmail.com>
> > ---
> > net/smc/smc_pnet.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
> > index b391c2ef463f..b70e1f3179c5 100644
> > --- a/net/smc/smc_pnet.c
> > +++ b/net/smc/smc_pnet.c
> > @@ -370,7 +370,7 @@ static int smc_pnet_add_eth(struct smc_pnettable *pnettable, struct net *net,
> > goto out_put;
> > new_pe->type = SMC_PNET_ETH;
> > memcpy(new_pe->pnet_name, pnet_name, SMC_MAX_PNETID_LEN);
> > - strncpy(new_pe->eth_name, eth_name, IFNAMSIZ);
> > + strscpy(new_pe->eth_name, eth_name, IFNAMSIZ);
>
> Hi Pranav,
>
> I think that because strscpy always results in a NULL terminated string
> the length argument can be increased by one to IFNAMSIZ + 1, matching
> the size of the destination.
>
> But I also think that we can handle this automatically by switching
> to the two-argument version of strscpy() because the destination is an
> array.
>
> strscpy(new_pe->eth_name, eth_name);
>
> > rc = -EEXIST;
> > new_netdev = true;
> > mutex_lock(&pnettable->lock);
> > --
> > 2.49.0
> >
>
> --
> pw-bot: changes-requested

Hi,

Thanks for the feedback. Apologies for the oversight.
The size parameter should match the size of the destination.
Anyway, I will now use the two-argument version
send a v2.

Regards
Pranav Tyagi