Re: [PATCH net-next 4/4] net/tcp_ao: use sock_kmemdup for tcp_ao_key

[Geliang Tang <geliang@kernel.org>]

On Thu, 2025-02-27 at 09:35 +0100, Eric Dumazet wrote:
> On Thu, Feb 27, 2025 at 9:24 AM Geliang Tang <geliang@kernel.org>
> wrote:
> > 
> > From: Geliang Tang <tanggeliang@kylinos.cn>
> > 
> > Instead of using sock_kmalloc() to allocate a tcp_ao_key "new_key"
> > and
> > then immediately duplicate the input "key" to it in
> > tcp_ao_copy_key(),
> > the newly added sock_kmemdup() helper can be used to simplify the
> > code.
> > 
> > Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> > ---
> >  net/ipv4/tcp_ao.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> > 
> > diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c
> > index bbb8d5f0eae7..d21412d469cc 100644
> > --- a/net/ipv4/tcp_ao.c
> > +++ b/net/ipv4/tcp_ao.c
> > @@ -246,12 +246,11 @@ static struct tcp_ao_key
> > *tcp_ao_copy_key(struct sock *sk,
> >  {
> >         struct tcp_ao_key *new_key;
> > 
> > -       new_key = sock_kmalloc(sk, tcp_ao_sizeof_key(key),
> > +       new_key = sock_kmemdup(sk, key, tcp_ao_sizeof_key(key),
> >                                GFP_ATOMIC);
> >         if (!new_key)
> >                 return NULL;
> > 
> > -       *new_key = *key;
> 
> Note that this only copies 'sizeof(struct tcp_ao_key)' bytes, which
> is
> smaller than tcp_ao_sizeof_key(key)

Yes, indeed. sock_kmemdup() shouldn't be used here then. I'll drop this
patch in v2.

Thanks,
-Geliang