On Sun, Apr 11, 2021 at 11:52 PM Karsten Graul <kgraul@xxxxxxxxxxxxx> wrote:
>
>
>
> On 10/04/2021 20:17, Cong Wang wrote:
> > From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> >
> > syzbot is able to setup kTLS on an SMC socket, which coincidentally
> > uses sk_user_data too, later, kTLS treats it as psock so triggers a
> > refcnt warning. The cause is that smc_setsockopt() simply calls
> > TCP setsockopt(). I do not think it makes sense to setup kTLS on
> > top of SMC, so we can just disallow this.
> >
> > Reported-and-tested-by: syzbot+b54a1ce86ba4a623b7f0@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Cc: John Fastabend <john.fastabend@xxxxxxxxx>
> > Cc: Karsten Graul <kgraul@xxxxxxxxxxxxx>
> > Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
> > ---
> > net/smc/af_smc.c | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> > index 47340b3b514f..0d4d6d28f20c 100644
> > --- a/net/smc/af_smc.c
> > +++ b/net/smc/af_smc.c
> > @@ -2162,6 +2162,9 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
> > struct smc_sock *smc;
> > int val, rc;
> >
> > + if (optname == TCP_ULP)
> > + return -EOPNOTSUPP;
> > +
> > smc = smc_sk(sk);
> >
> > /* generic setsockopts reaching us here always apply to the
> > @@ -2186,7 +2189,6 @@ static int smc_setsockopt(struct socket *sock, int level, int optname,
> > if (rc || smc->use_fallback)
> > goto out;
> > switch (optname) {
> > - case TCP_ULP:
>
> Should'nt it return -EOPNOTSUPP in that case, too?
I do not think I understand this. In case of TCP_ULP, we will
not even reach this switch case after my patch.
Thanks.
