Re: [PATCH] net: tls: fix possible race condition between do_tls_getsockopt_conf() and do_tls_setsockopt_conf()

[Hangyu Hua]

On 28/2/2023 03:07, Jakub Kicinski wrote:
> On Mon, 27 Feb 2023 11:26:18 +0800 Hangyu Hua wrote:
> > In order to reduce ambiguity, I think it may be a good idea only to
> > lock do_tls_getsockopt_conf() like we did in do_tls_setsockopt()
> >
> > It will look like:
> >
> > static int do_tls_getsockopt(struct sock *sk, int optname,
> > 			     char __user *optval, int __user *optlen)
> > {
> > 	int rc = 0;
> >
> > 	switch (optname) {
> > 	case TLS_TX:
> > 	case TLS_RX:
> > +		lock_sock(sk);
> > 		rc = do_tls_getsockopt_conf(sk, optval, optlen,
> > 					    optname == TLS_TX);
> > +		release_sock(sk);
> > 		break;
> > 	case TLS_TX_ZEROCOPY_RO:
> > 		rc = do_tls_getsockopt_tx_zc(sk, optval, optlen);
> > 		break;
> > 	case TLS_RX_EXPECT_NO_PAD:
> > 		rc = do_tls_getsockopt_no_pad(sk, optval, optlen);
> > 		break;
> > 	default:
> > 		rc = -ENOPROTOOPT;
> > 		break;
> > 	}
> > 	return rc;
> > }
> >
> > Of cause, I will clean the lock in do_tls_getsockopt_conf(). What do you
> > guys think?
>
> I'd suggest to take the lock around the entire switch statement.

I get it. I will send a v2 later.

Thanks,
Hangyu