From: John Fastabend <john.fastabend@gmail.com>
To: Jakub Kicinski <jakub.kicinski@netronome.com>,
John Fastabend <john.fastabend@gmail.com>
Cc: ast@kernel.org, daniel@iogearbox.net, netdev@vger.kernel.org,
edumazet@google.com, bpf@vger.kernel.org
Subject: Re: [bpf PATCH v2 6/6] bpf: sockmap/tls, close can race with map free
Date: Thu, 11 Jul 2019 09:39:53 -0700 [thread overview]
Message-ID: <5d276659122cc_698f2aaeaaf925bc3e@john-XPS-13-9370.notmuch> (raw)
In-Reply-To: <20190710123543.04846e00@cakuba.netronome.com>
Jakub Kicinski wrote:
> On Tue, 09 Jul 2019 20:33:58 -0700, John Fastabend wrote:
> > Jakub Kicinski wrote:
> > > On Mon, 08 Jul 2019 19:15:18 +0000, John Fastabend wrote:
> > > > @@ -352,15 +354,18 @@ static void tls_sk_proto_close(struct sock *sk, long timeout)
> > > > if (ctx->tx_conf == TLS_BASE && ctx->rx_conf == TLS_BASE)
> > > > goto skip_tx_cleanup;
> > > >
> > > > - sk->sk_prot = ctx->sk_proto;
> > > > tls_sk_proto_cleanup(sk, ctx, timeo);
> > > >
> > > > skip_tx_cleanup:
> > > > + write_lock_bh(&sk->sk_callback_lock);
> > > > + icsk->icsk_ulp_data = NULL;
> > >
> > > Is ulp_data pointer now supposed to be updated under the
> > > sk_callback_lock?
> >
> > Yes otherwise it can race with tls_update(). I didn't remove the
> > ulp pointer null set from tcp_ulp.c though. Could be done in this
> > patch or as a follow up.
>
> Do we need to hold the lock in unhash, too, or is unhash called with
> sk_callback_lock held?
>
We should hold the lock here. Also we should reset sk_prot similar to
other paths in case we get here without a close() call. syzbot hasn't
found that path yet but I'll add some tests for it.
write_lock_bh(...)
icsk_ulp_data = NULL
sk->sk_prot = ctx->sk_proto;
write_unlock_bh(...)
Thanks
next prev parent reply other threads:[~2019-07-11 16:40 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-08 19:13 [bpf PATCH v2 0/6] bpf: sockmap/tls fixes John Fastabend
2019-07-08 19:13 ` [bpf PATCH v2 1/6] tls: remove close callback sock unlock/lock and flush_sync John Fastabend
2019-07-08 19:14 ` [bpf PATCH v2 2/6] bpf: tls fix transition through disconnect with close John Fastabend
2019-07-10 2:45 ` Jakub Kicinski
2019-07-10 3:39 ` John Fastabend
2019-07-10 19:34 ` Jakub Kicinski
2019-07-10 20:04 ` Jakub Kicinski
2019-07-11 16:47 ` John Fastabend
2019-07-11 18:32 ` Jakub Kicinski
2019-07-11 21:25 ` John Fastabend
2019-07-12 3:16 ` Jakub Kicinski
2019-07-15 20:58 ` John Fastabend
2019-07-11 16:35 ` John Fastabend
2019-07-08 19:14 ` [bpf PATCH v2 3/6] bpf: sockmap, sock_map_delete needs to use xchg John Fastabend
2019-07-08 19:14 ` [bpf PATCH v2 4/6] bpf: sockmap, synchronize_rcu before free'ing map John Fastabend
2019-07-08 19:15 ` [bpf PATCH v2 5/6] bpf: sockmap, only create entry if ulp is not already enabled John Fastabend
2019-07-08 19:15 ` [bpf PATCH v2 6/6] bpf: sockmap/tls, close can race with map free John Fastabend
2019-07-10 2:36 ` Jakub Kicinski
2019-07-10 2:38 ` Jakub Kicinski
2019-07-10 3:33 ` John Fastabend
2019-07-10 19:35 ` Jakub Kicinski
2019-07-11 16:39 ` John Fastabend [this message]
2019-07-09 6:13 ` [bpf PATCH v2 0/6] bpf: sockmap/tls fixes Jakub Kicinski
2019-07-09 15:40 ` John Fastabend
2019-07-10 0:04 ` Jakub Kicinski
2019-07-10 2:21 ` Jakub Kicinski
2019-07-10 3:28 ` John Fastabend
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